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HomeMy WebLinkAbout1999-11-18RIVANNA WATER & SEWER AUTHORITY !=. O. BOX 18 · CHARLOTTESVILLE, VIRGINIA 22S02-0018 · (SO4) FUTURE WATER SUPPLY PROJECT INFORMATION PACKET PRELIMINARY ALTERNATIVES PUBLIC MEETING APRIL 20, 1999 PRESENTED BY RIVANNA WATER AND SEWER AUTHORITY AND VANASSE HANGEN BRUTLIN, INC. \XFS2\Shared Documents\Water\Cover sheet with contents of VHB CQA sheet.doc SERVING CHARLOTTESVILLE & ALBEMARLE COUNTY CONTENTS Preliminary Alternatives Public Information Meeting Minutes with Comments, Questions and Answers ................................................................................ 1-8 Elizabeth Murray Letter ................................................................................. 9 Lawrence S. Miller Letter ........................................................................ 10-13 League Of Women Voters - Marsha Parkinson Letter ...........................................14-18 Donna Bennett to Sally Thomas E-mail .......................................................... 19-23 Southern Environmental Law Center (SELC) Deborah Murray/Kay Slaughter Letter .... 24-25 Donna and Jim Bennett Letter ...................................................................... 26-30 William McDonough + Partners Letter ........................................................... 31-35 League of Women Voter and Charlottesville/Albemarle County Rivanna River Basin Roundtable Letter .................................................................................... 36-37 \XFS2\Shared Documents\Water\Cover sheet with contents ofVHB CQA sheet, doc RIVANNA WATER & SEWER AUTHORITY I=. O, l=lOX 18 · CHARLOTTIESVILL. I"-. VIRGINIA 22g~02-OO$8 t (804) Rivanna Water & Sewer Authority Water Supply Project Preliminary Alternatives Public Information Meeting Minutes April 20, 1999 A public meeting of the Rivanna Water and Sewer Authority (RWSA) was called to order on Tuedsay, April 20, 1999, at 7:00 p.m. by Mr. Arthur D. Petrini, Executive Director, RWSA, in the Council Chambers, City Hall, Charlottesville, Virginia. Mr. Petrini opened the presentation with a special thanks to the League of Women Voters for their assistance in the preparation of materials and for advertisement of this meeting. Mr. Petrini then introduced Ms. Nancy Barker, Project Manager, for Vanasse Hangen Brustlin, Inc. (VHB). Ms. Barker stated that the members of the VHB team were all pleased to be there to describe the permit process that RWSA is embarking on and to present information gathered to date on the preliminary list of alternatives. Ms. Barker introduced the VHB team members: Ms. Karin Ertl, who is responsible for the environmental evaluation, and Mr. Larry Welford, who is responsible for the demand analysis. Ms. Barker introduced the O'Brien and Gere Engineers team members: Mr. George Rest, who is responsible for the supply analysis and oversight of the engineering analysis and Mr. Thomas Dumm, who is responsible for the engineering investigations. Ms. Barker introduced Mr. Bill Ellis, of McSweeney, Burtch and Cramp, who is the RWSA's legal counsel. Ms. Barker stated that Mr. Ellis is very familiar with water supply projects and is providing input on regulatory issues and permitting requirements. Ms. Barker stated that there are also several other members of the team including the consulting firm of Gray and Pape, Inc. who are conducting the cultural resources investigations and several independent consultants who are assisting VHB with threatened and endangered species surveys. Ms. Barker then gave a brief explanation of the agenda [attached]. Ms. Barker turned the presentation over to Mr. Ellis. Mr. Ellis noted that he appreciated the opportunity to work with RWSA and to speak with the public about their water supply needs. Mr. Ellis said that depending on the alternative that is selected, there may be no permits required or there may be many permits that are required. He said that at this point, their job is to gather the necessary information that will be needed to satisfy the regulatory agencies and any legal requirements that might be applied to the alternative or combination of alternatives that may be chosen. Mr. Ellis stated that one of the most important parts of this project is the complex inter-relationships between all of the local, state, and federal agencies that may be involved. Mr. Ellis stated that his job is to make sure that all the agencies and legal requirements are satisfied so that the RWSA only goes through this process once. With respect to alternatives, Mr. Ellis said that he believed the most challenging, restrictive and demanding standards to satisfy are those administered by the U.S. Army Corp of Engineers and the United Stated Environmental Protection Agency. These agencies can only issue a permit for the -1- H:\Water'~RWSA Public Meeting minutes04-20-99 updated 6-17-99.doc SERVING CHARLOTTESVILLE & ALBEMARLE COUNTY least environmentally damaging practicable alternative. Mr. Ellis said that when considering "practicability", technical feasibility, cost and logistics are all reviewed. Mr. Ellis said that tonight, summaries of the alternatives developed to date would be presented. With respect to each alternative, the basic questions to be addressed would be: what are its environmental effects; what are its costs; what are its logistical considerations; is it technically feasible; and to what extent, if any, will the alternative assist the community in meeting its water needs? Mr. Ellis stated that the study team has been assembling information and preparing documentation for each alternative and is now presenting this information to the community so they can provide RWSA with their input. This information will also be presented to the regulatory agencies for their review and comment. Mr. Ellis stated that the alternatives are currently being evaluated and that the team hopes that the community will be a part of this evaluation process. Mr. Ellis turned the presentation over to Mr. Rest. Mr. Rest said that the study began by looking at what sources of supply are providing raw water to the Urban Service Area. Mr. Rest stated that there are currently three source of raw water: 1) the S. Fork Rivanna River Reservoir, 2) the Sugar Hollow/Ragged Mountain Reservoir System, and 3) the N. Fork Rivanna River. He said that their task was to determine the safe yield (the amount of water that can be supplied in a severe drought situation) of this water supply system through 2050, the planning period that was selected for this study. Mr. Rest discussed the process of sedimentation which gradually silts in reservoirs and how this decreases the productive life of a reservoir, particularly the S. Fork Rivanna Reservoir. As a result, the safe yield of the water supply system is actually decreasing over time. Mr. Rest mined the presentation over to Mr. Welford. Mr. Welford said that in late 1997, the VHB team produced two reports, one of which documented the supply analysis and the other which documented the demand analysis for the Urban Service Area. [The Supply Analysis Report and the Demand Analysis Report are available from RWSA]. Mr. Welford stated that the reports were presented to the public and were also submitted to the regulatory agencies for their review and comment. To examine water demand, Mr. Welford explained the fact that the Authority has two customers, the Albemarle County Service Authority (ACSA) and the City of Charlottesville (which includes the University of Virginia). The City and the ACSA then retail the water to the end users. Mr. Welford said that the system here is unique in that the water is metered in only two general locations. The raw water intake into the system is metered at each of the water treatment plants and then also at the end user (the residential home, business, etc.). Mr. Welford described how four approaches were used to predict future water demand for this system: 1) projecting historic trends in raw water volumes, 2) projecting population trends and per capita water consumption, 3) prediction of consumption based on full build-out as defined in the City and County Comprehensive Plans, and 4) projecting historic trends in demand for each individual component of the system. For purposes of analysis, the system was broken down into 5 primary components: 1) the City of Charlottesville, 2) the University of Virginia, 3) the ACSA, 4) water uses currently outside of the Urban Service Area, and 5) unmetered water use (includes fire fighting, street washing, etc.). Mr. Welford defined "water uses outside of the Urban Service Area" as residential developments that rely on wells for their water supply but which are- expected to be brought into the Urban Service Area in the future. In fact, subsequent to the Demand Analysis Report release, one of those communities was brought into the RWSA's Urban Service -2- H:\Water~RWSA Public Meeting minutes04-20-99 updated 6-17-99.doc Area system. He stated that when the information from the Demand Analysis and the Supply Analysis are brought together, one can understand why we are here: the demand for water is growing and the supply of water is decreasing. It was important for the Authority to move forward with identifying solutions to this problem and that is what this team has embarked on, on behalf of RWSA. Mr. Welford turned the presentation back to Ms. Barker. Ms. Barker noted that the Authority, for the last 20 years or so, has had several studies done to evaluate potential water supply alternatives. She stated that the VHB team went back through those studies and reviewed and re-evaluated the alternatives that had been identified previously. In addition, the study team developed a wide range of new potential alternatives. Ms. Barker explained that what they have done is compile a series of alternatives that can be broken down into two primary categories. One category of alternatives represents some sort of improvement to the efficiency of the existing resources. This includes modifications to existing reservoirs, drought management, water conservation, and reducing sediment loads into the S. Fork Rivanna River Reservoir. The second category represents physical additions to the existing water supply system and includes options such as the construction of a new reservoir or surface water withdrawals. Ms. Barker said they will describe the 30+ alternatives that have been identified, each of which falls into one of those two categories. Ms. Barker indicated that these alternatives were evaluated from both an engineering and an environmental perspective. She said that they had made preliminary evaluations of the projected cost, the potential safe yield, feasibility, and potential environmental impacts to sensitive resources such as wetlands, threatened and endangered species, historic sites and residential displacements. Ms. Barker stated that those items are the groundwork for the evaluation of each alternative. Ms. Barker went over the assumptions used to develop and cost each alternative, which is located in the draft Water Supply Project Preliminary Alternatives document. [attached] Ms. Barker turned the presentation over to Ms. Ertl and Mr. Dumm both of whom then summarized the available information compiled and developed on each alternative to date. Mr. Dumm addressed the safe yield, cost and technical feasibility of each alternative while Ms. Ertl addressed the environmental issues associated with each alternative. All of the information presented was included in the preliminary alternatives document available at the meeting. Following the review of alternatives, Mr. Dumm turned the presentation over to Mr. Ellis. Mr. Ellis described another alternative under investigation aimed at reducing future water demand: growth management within the Urban Service Area. Mr. Ellis reminded everyone that a large part of the future water deficit occurs as a result of a decrease in existing supply, not a result of increase in demand. The population in the City of Charlottesville is not projected to grow significantly through the year 2050. In Albemarle County, this alternative looks at projected growth within the Urban Service Area portion of the county. He noted that it has been the policy of the county to intentionally channel and direct growth into the Urban Service Area, a policy which has been successful over the last 20 years at least. The growth management alternative would restrict growth in the Urban Service Area and essentially reverse the existing policy. He said that if this was done and was effective, that it would probably result in greater growth in the present rural areas of Albemarle County outside of the Urban Service Area. Mr. Ellis stated that some of the effects of this alternative would be the need for infrastructure improvements in the rural areas, such as -3- H:\Water\RWSA Public Meeting minutes04-20-99 updated 6-17-99. doc additional roads and utilities. If the policy were successful, the study team estimated the reduction in demand within the Urban Service Area might reach as much as 1.5 MGD. Mr. Ellis described another alternative that looks at cooperating with other water service providers in the region. He explained that "Regional Cooperation" is the sharing of resources among neighboring jurisdictions in order to reduce the environmental effects of each jurisdiction pursuing separate projects. He said that geography is such that, for the most part, this is not a very promising alternative. He said that in general, the public suppliers in the area are far away and they serve a dispersed population with no great demand. He said that the only real opportunity identified for possible regional cooperation is with the Rapidan Service Authority (RSA), which serves four isolated areas in Greene, Madison, Orange and Louisa counties. The closest these two systems come to one another is approximately 4 miles - - RWSA has a pipeline that proceeds north adjacent to Route 29 and comes within about 4 miles of a smaller RSA line to the north. Mr. Ellis stated that the existing pipes might need to be replaced if the two systems were interconnected. Based on recent information, the Rapidan Service Authority is also expecting an unmet future demand and does not yet know where their 2050 water supply will be coming from. He said that the study team is trying to do the best they can to identify what opportunities do exist for regional cooperation in order to satisfy regulatory requirements. There were comments, questions and answers after the presentation. The public was asked to send written comments to either VHB or RWSA and to feel free to call if they had any other questions, comments, or concerns. Ms. Barker thanked the public for their questions, comments and input and noted that the study team looked forward to hearing from the community. Mr. Petrini thanked the public and adjourned the meeting at 9:35 p.m. -4- H:\WaterXRWSA Public Meeting minutes04-20-99 updated 6-17-99.doc PLIBLIC INFORMATION MEETING Water Supply Project: Permit Process Update and Alternatives Presentation Sponsored by: Rivanna Water & Sewer Authorit~ Tuesday, April 20, 199g LOCATION: CITY OF CHARLOTTESVILLE CITY COUNCIL CHAMBERS TIME: 7:00 PM TO 9:30 PM AGENDA II. IH. IV. VIe INTRODUCTION 0 Introduction of Study Team PERMIT PROCESS OVERVIEW 0 General Phases o£ Permit Process SUMMARY OF WATER SUPPLY NEEDS 0 Existing and Future Water Supply 0 Existing and Future Water Demand WATER SUPPLY ALTERNATIVES ~ Structural Alternatives ~ Non-structural Alternatives NEXT STEPS 0 Where We Go From Here PUBLIC INPUT/QUESTIONS AND ANSWERS \\willva\projects\30502\wp\mise~PIO42099agenda -5- WATER SUPPLY ALTERNATIVES COMMENTS-QUESTIONS-ANSWERS Public Meeting April 20, 1999 7:00 P.M. Attendees Study Team: Art Petrini - Rivanna Water & Sewer Authority Bill Ellis - McSweeney, Brutch & Crump Larry Welford - Vanasse Hangen Brustlin, Inc. Nancy Barker - Vanasse Hangen Brustlin, Inc. Karin Ertl - Vanasse Hangen Brustlin, Inc. George Rest - O'Brien & Gere Engineers, Inc. Thomas Dumm - O'Brien & Gere Engineers, Inc. Comment: For the Growth Management alternative, recommendation that a reduction in growth in the Urban Service Area not necessarily result in increased growth in the rural area. Comment: The following four alternatives should be implemented in the near term: · Growth Management · Demand Management · Water Conservation · Leak Detection Comment: Additional land may be needed around Buck Mountain due to proposed road around mountain shown on a map available from the RWSA, causing an impact to residences. Comment: Support designation of county owned land near Preddy Creek as a Natural Area. A reservoir in this location would be compatible with such a designation. Comment: · · · Four fundamental principles to keep in mind: Optimize instream flows; impact to Moormans River is unacceptable. Water conservation is a must. With 45" of rain/year, the community should be able to live within limits of the watershed - no regional cooperation. Leverage what already have: 1. 2. 3. 4. Strongly support reducing siltation into reservoir Strongly support aggressive water conservation Ought to keep in the retrofit option Support Reuse option -6- H:\Water\Public Meeting Question and Answers for 04-20-99. doc April 20, 1999 Page 2 Comment: In addition to the macroscale level of reuse, it may be useful to also consider a more microscale reuse option; i.e. the treatment of residential/commercial wastewater from landscaping, golf course irrigation, etc. Comment: The groundwater safe yield is accurate; maybe even too generous. Comment: Look hard at water conservation and retrofit options. Comment: Complimentary of the wide range of alternatives under consideration. Comment: It would be beneficial to also see the operations/maintenance costs associated with the alternatives. Question: Is the study team looking at the potential for sedimentation associated with new reservoirs? Answer: Yes Question: Is the cost of dredging the S. Fork Rivanna Reservoir reduced if the reservoir is put off-line during the dredging event? Answer: The cost would be reduced only minimally. Question: Is it true that the City of Richmond has exclusive water rights to the James River? Answer: No Question: Did the study team do their own groundwater investigation? Safe yield of 0. lmgd sounds low. Answer: The study team did not perform groundwater investigations; information on groundwater was obtained from the Virginia Department of Environmental Quality. Question: Why is there a range in safe yield of 4.1 to 4.8 mgd for the existing Sugar Hollow/Ragged Mountain Reservoir system? Answer: Uncertainty due to 1930's versus 1954 drought of record. -7- April 20, 1999 page 3 Question: Are the land costs based on current value? Answer: Yes; $!l,O00/acre Question: Is consideration being given to a MIF release at the Sugar Hollow Reservoir? Answer: The Rivanna and Water Sewer Authority Board's written policy statement is that consideration of an MIF will be given when a new water supply is available. Question: What is the expected time line for completion of the study? Answer: The time will vary depending on the alternative(s) that is implemented. -8- 20 April 1999 For Hearing 0;%. Future Public Water Resources My name is Elizabet~: and I'm the former Co=ordinator at the Ivy Creek Natural Ar( as ~x~s=_~,f_ yo_u k~ow, locate~'%n the. ~O_Uth Rivanna Reservoir. I was a volunteer Board membe~ ~=~ TM Ivy Creek Foundatton~'~-~'~elped the City and County establish and then mana§e the A~ea~ and co-ordinator for ten years. Watershed protection was a big selling point in the establishment of the Area, unfor=uns.tely it doesn't do enough~ the Area is only round par= of the reservotr and hasn't saved tt from =he probl~ we're all ~are of. Pity ~ doesn't ~o all the way round. I resSgned partly to devote ~re ~me ~o the establtsh~nt of otherApublic Natural Areas, ~ fifteen years ~here had been none, despite all o=. ~rowth. I'm happy =o may now we have one ~=e In =he Clty/Co~ty area~ Ragged ~untat~a~ ~h~ch doe~ go all the ~ay ro~d =he ReSEed Mo~tain Reservoir. I started looking at other public land~ and County staff directed me to Preddy Creek, 268 acres, bought specifically with future water resources in m/nds and when I first raised the ~dea of designating ~t a Natural Area, I was told there mi§hr be a reserve there.. T~at's not necessarily incompatlble with a Natural Area. In fact as watershed protectfon~ a Natural Area is about the Best. thinE you could have round a reservoir, plus the benefit of ~nother public amenity for passive recreation. In 1985 there was a rumor that Preddy 'Greek might be sold or logsed, and a former State For.ester and his Deputy submitted a~ independent report urging the Gounty to do neither. This report is in the public record. In 1995 I wemt back to ?teddy .cr~em~.k~tth one of these foresters and we submitted a further report re-iterating the same g-h~ and also urging that in the upcoming Comprehensive Plan revision Freddy Creek be earmarked as e future Natural Area. This is also in the publle record. A~d I'm happy to say that early this year, during the hea~lngs for the ~=ap=er two r~v~s~ons of =he Comprehensive Plan~ the worain~ on Preddy Creek was amended to reflect a need to study it for future passive recreation. I understand ~t's not at the top of your list as a future reservoir site, but I would ltk~ to ask you~ pleases to remember as you d~scuss it, that there is this history of support= for Natural Area desi~nation~ so that any reservoir construction ~ould be compatib].e with future natural area status ..... ..... ,a~d indeed, o~ any o~her sites ~hat you consider for a reservoirs plea;e consider aleo that public land permanently desi~nated Natural Area ~s the best possible protectio~ for any watershed~ plus providing additional public amenity. Elizabeth Murray 1601 Bent]lvar Farm Road Charlotte;;ville VA 22911 (804) 973-6693 Thank You -9- April 23, 1999 Lawrence S. Miller P. O. Box 6 Free Union, VA 22940 lqaney Barker Vanasse Hangen B~ 477 McLaws Circle~ Suite 1 Willi~masburg, VA 23185 Dear Ms. Barker. Thank you leading the very informative public presentatioa on the RWSA's water supply options. I regr=t that I missed the prior pubI/c meeting on th/s subject. A nu~aber of questions and comments have come to mind since last Tuesday's meeting: Comlmrison of Wetland Losses Will the relative value ofwetIands inundated by the various alternatives be considered, or wilI onIy total l~reage be part of the decision? Crest controls for south l~ork Rivanna Dam are estimated to inundate up to 39 acres. However, most of those wetlands were probably created incidental to the ori~,/n~l impotmdmem. They are man.made. Their loss wilt be completely mitigated by the new wetlands created when tha pool elevation is increased. In contrast, naturally occurring wetlands ~ be los! to a new reservoir. These will not be replaced by wetlands of equivalent ecological or enviromnental value. In comparing wefl~ losses of the various alternatives, a distinction should be m_~de i~ween natural wetlands and 8oncomitant wetlands. Propert), Tax losses The project assumptions make no mention ofpotentiaI property tax Iosses to Albemarle County. Some :alternatives require the acquisition of large areas of land. For example, RWSA acquired or encumbered nearly 2000 acres for the Buck Mountain reservoir site. Much of this land is currently leased., with lessees paying the taxes. AP~ impotmdme~ wilt R.WSA pay property taxes? If so, has th/s be~n included in the unit cost (S/gallon) or project costs? Ii'not, will the i~-an¢ial impact on ~e coun~ be corns/tiered?. -10- Laml Acquisition for Buck Mountain Alternative Contrary to statements/n the project descriFt/on, new land acquisition may be necessary. The Iand thus l~ar acquired was based on a normal pool elevation of 464 feet. The project description mentions a normal pool elevation of 480 fee~ This pool elevation will inundate land the RWSA does not own, I believe this will only affect land subject to RWSA. easements, but the easements do not grant rights to flood this land. Development Attraction of New Impoundments Lake.,; and reservoirs tend to attract development. Albemarle Cotmty is already stru§gling with .gro~_'h issues, and of course this is one reason for this project. Although a new impoundment may be part of the 'solution for the area's water needs, it also becomes part of the problem. Impact on South Fork Rivanna Reservoir Several of the alternatives consist of new impoundments in the existflag South Fork reservoir's watershed. Do the calculated increases in safe yield quantities for these impoundment alternatives account for losses they will came to the existing reservoir, or are safe yields only calculated for the retirement date (2050) of the existing reservoir7 How will these impotmdmen~s affect the ability to mai_~_, a/n required flowby at the South Fork clam? New impoundments in the existing watershed are reaIIy just additional storage devices. Wouldn't it be more lag/cai to deveIop a new sowce, i.e. a cliffenmI watershed? Wate:rshed Area and Prolonged Droughts Is tokai watershed area a limiting factor/n meeting demand during proIonged drougt~t7 W~ storage ciq~acity alone be mxfficient to get us through any foreseeable drought? Could global warming invalidate assumptions about drought duration or severity? It would seem that we could increase our rear, ha of safcO/by locating any new reservoir 6utside the South Fork watershed. Increase-in-Safe-Yield Calculations In tetras of/ncrease/n safe. yield, the North Fork R/va~na option exceeds the Buck Mounm/n opt/on by onl:y 7%. Yet thc North Fork Reservoir would have a storage capacity 9 I% greater and a watershed area 65% greater, Is this anomaly solely the result of the lower percent flowby assumed .for the. Buck Mountain option? Can we safely assume this favorable flowby require-meat will not cb ,~mg~: during the life of the impoundment? How would the yields for these two options compare using lhe same percent flowby assumpt/on for each? FIowby and Environmen~i Tradeoffs FIowby requ/remen~s appear to be one ortho most significant constra~ts ~n produdng a I~gh sa~'e yield from a reservoir. I know flowby requirements axe intended to ~eve~t ecological har~ to streams, but how many miles of stream above the dam are we entirely eliminating to avoid occasional damage to the s~rea~ below th~ dam? The revised flowby regimen akernativc for thc South Pork rezePtoir yields an addi~oaal 3.8 mgd without redu¢ir~g flow below ~mraI levels during drought. How much more y~elcl woulc[ be obta~ed /f we were ~ to accept lower flow rates during drought events? Any. damage sustz~ed by this practice would probably be limited to the 3-mile segment between the South Fork dam and the confluence with the North Fork. Compare this to the ~prc.ximately 20 miles of str~_m_s and tributaries that would be flooded by any one cf the new reservoir options. Recommendations In tetris of cost effective~s, dislocations, and enviroumental impacts, pumPback to thc South Fork Reservoir is clearly thc best single-fix option. Rccycling water ~is way will probably be common by 2050, but there migh~ be some problems with public perceptions today. PhasB~g-m several low-yield options n~y be nex~ b~st. I have attached a list of the leas~ object,on'lo and most pra~cal low-yield options. I believe that none of these options affect the practi,~diW of the others on the list. Although I have listed six optiom, notice tha~ the fu'st five options show .~ net yield grea~er tha~ the most cost-effective new reservoir option (Buck Mountain), but at one hfflt'the cost, and without dislocations, acquisitions o.r si~o~i~cant wetland impact. We s~ould maintain and/or upgrade existing sources to the extent poss~le to meet future needs. We shouldn't destroy another stream and its adjacent wetlands when the resulting reservoir will ultimately fill with sediment antnzray. If a new impound .m_er~ is the o~ly solution, then it should be bulk outside the South Fork water~he~ Your ~sponse to my comments will be very much appreciated, lvlany of my questions are just rheton!c~l, bu~ in the hope you con provide answers to thc othci's, I will look forward to hearing from you. S c ly, · Lawrence S. Miller cc: BE['Ellis, McSwcency Buctch & Crump -13- 1928 Ayilngton Blvd., Room 105, Ottatlotteevlll®, VA ;a~;:)3 (804) 970-1707 Plane {8(~4) 971-1708 Fax May 17,1999 Mr. A~thur Petrini, Executive Director RiYanna Water and Sewer Authority Post Office Box 18 Charlottesville, Virginia 22902 Dear Mr. Petrini: We, the Charlottesville/Albemarle Chapter of the League of Women Voters, are writing to provide our responses to the "Water Supply Project: Preliminary Alternatives" meeting held April 20, 1999, during which your consultants, VHB, presented their analysis of water demand and supply alternatives for out area, We have long supported water conservation and stewardship of the natural environment in the Charlottesville/Albemarle area. Thus, we especially applaud those Alternatives which recommend the reuse and more efficient use of water, and the protection and recovery of existing water sources. In order to educate the public on these important subjects, we have written articles, prepared a booklet '~/ater in the New Millennium: Balancing the Needs of People and the Environment', recommended the creation of a Citizen Advisory Board to the RWSA, and invited VHB to speak at a League meeting early in the "permitting process". Also, as part of this effort, we have promoted "public undersfanding and participation in decision making as essential elements and responsive management of our natural resources", a National League of Women Voters position. For this reason, we have remained integrally involved in the ".permifling process" since it began two and a half years ago. During that time, one of our top priorities has been to encourage a meeting for community-wide participation in the analysis of our water demand and supply problems. Our commitment to encouraging community input arises from our belief that, as a co~nmunity, we must plan wisely for the future. The future development of water supply resources ia not an issue related only to providing adequate potable water, but rather is an extremely important component of the overall community-planning process. Our commitment to informed decision making by our community provides the context for the comments and questions by League members, which are included below. Three areas are of special interest to us: 1) the nature and extent of the April meeting, 2) the informational content of the meeting, and 3) the scope of the Water Conservation and Drought Management Plans presented as Alternatives. I. The Nature and Extent of the Meeting: The April meeting took place late in the VHB study process. Until that time. there had been little opportunity for community consensus -14- building, For two and a half years, while VHB completed an evaluation, of water supply and demand and compiled their final report for presentation to regulatory agencies, most of the public has had only a vague awareness that a "permitting process" for a water supply was under way. The April meeting represented an important chance to bring about public discussion regarding which alternative or alternatives our community felt would be the most practicable, environmentally sound way to meet its future water demands. The meeting emphasized information, not an open discussion of the VHB report. During the necessarily short question period, a wide range of citizens' concerns was introduced. Some comments and questions required additional information or answers that could not be given to the public at that time, For example, one person noted that costs were presented as "apples and oranges" and requested a conversion chart. Another person asked whether the South Fork Rivanna Reservoir would be abandoned? And if so, what would be the cost? Many asked questions about water conservation. We think a follow-up meeting should have been scheduled to address these concerns, in advance of the meeting RWSA and VHB will have with regulating agencies on May 21, 1999. Since a follow-up meeting did not occur, we hope another public meeting will take place before too many further decisions ara made. 2. The Informational Content of the Meeting: The following comments and questions address those areas we think need either clarification or additional information to assist us public in making an informed decision among alternatives; GRAPHS. a. A variety of scenarios at the out, et of the VHB study. Why dlcl VHB present only the worst case scenado for demand and not model other outcomes-such as, population growth with a 10% or a 20% reduction in water consumption, or limited population growth combined with reduction of demand? At a February, 1999, RWSA Board of Directors Meeting, a League member asked the consultants ~ they didn't Include a variety of graphs at the outset of thelr study. VHB representatives answered that they were waiting until they presented their list of Alternatives to the public, However, these graphs were not presented at the April 20th meeting. b. Demand. The demand figures are based on historical (unregulated) water demand in our community. Although a formal conservation plan requiring a permanent 10% reduction in water use was proposed and approved by RWSA in 1979, following the 1977 drought, it was never implemented, Our community would be considered irresponsible if it continued to use water as excessively as it has up lo the present. Why should we assume this rligh level of demand will continue for the next 50 year~? A series of graphs projecting water demand but incorporating 10% and 20 % reductions of water consumption shou Id have been presented for comparison. c. Population Growth. The graph that projects population growth and water demand depicts continuation of a hyperbolic growth rate in the Albemarle County servioe area, projected to the year 2050.Why didn't VHB also present more -1_5- conservative models, representlrtg a median between the slower growth rate that preceded '1 gg0 and the faster growth rate since the early '90's'? Graphs depicting both a more conservative population growth curve and more conservative water demand figures should have been offered, Worst Case Drought. The RWSA has utilized a graph titled "Supply and Demand" to depict the extent of a potential water defiGit through the year 2050. This graph is mislea~ling to all but the most careful observer, and it fails to contain information which is essential to fully understand and measure potential water supply deficits. The graph does not depict a decrease in actual water supply through 2050. It only depicts what the "worst case" water deficit would be for each veer if a moat severe drought occurred in that particular year. The interpretation is further confounded because the demand Line depicts the projected desire for water rather than the ~neeq f~r water. This is significant, because it is unrealistic to believe that un,er any drougl~t condition, the "demand" for water would (or should) remain at a constant accelerating level. This analysis ignores the fact that as drought conditions become more severe, more water ' would be conserved through voluntary and mandatory measures. At any point on the supply line, as a severe drought develops, the "demand" line would be expected to drop substantially, an~t the amount Of any actual deficit would not as great as the graph provided would suggest. None of this is meant to imply, however, that the provided graph does not depict an actual problem. Rather, the provided graph is presenting the discrepancy between supply and demand when D.o drouaht manaJ_~_ ement ~olicv is in effect. Thus, once the assumptions behind the provided graph are understood, it is obvious thai considerably more data is needed to enable the public to make judgments on what improvements we should make (and pay for) in our water supply system, ao All previous studies used the 1950's drought for predictions, which utilized actual flow data in our reservoir water sources to estimate safe yields. Changing to the 1930's drought for these estimations is limited to use of flow data from surrogate rivers, which may not be relevant to our situation. Thus, the validity of the recluced safe yield calculations is questionable. GENERALQ~JESTION. S ABOUT DATA. IN_THE VHB REPOR? a. Do the regulatory agencies verify tl~ information given by VHB regarding costs, estimations of environmental impact, etc., or ia all information assumed to be correct? b. At what point will VHB present a more detailed study to the public regarding: the operation and maintenance costs of different alternatives, the costs of buying parcels of lend, and the costa of replacing roadways, etc.? -16- _DATA IN a. Co SP ECIFIC_ALTE R~_~AT. IVE$ North Fork-Trio drainage area of the North Fork is 63 square miles. However, the rel3ort does not indicate that a large portion of the watershed lies in Greene County, and is not protected by Albemarle County's Watersl~ed Protection Policy. Crest Controls on the 8outh Fork Rivanna Reeervoir-VHB needs to clarify, what is meant by an increase of 'safe yield' for 4' and 8' crest. 4' will increase safe yield bv 6 mgd; 1 8' by 11 mgd. Have they considered the loss in mgd represented by the 8 mgd required to maintain aquatic life downstream in the Rlvanna? When Black and Veatch calculated the costs of crest controls for the SFRR, they included the costs of replacing the roadway (which would be inundated), the pumping station and the pil3e lines. VHB estimates trte 4' crest control would cost $4 million; Black and Veatch estimated $'19 million. VHB estimates the 8' crest control would cost $14 million; Black and Veatch estimated $28 million. These figures are substantially different. Also, Black and Veatch estimated more homes affected than VHB. Buck Mountain Reservoir, VHB omits mention of the necessity of replacing two roads and replacing two of Chaflottesvtlle's gas lines that otherwise would be buried beneath the reservoir. Thus, their estimate of cost is likely too Iow, and the environmental impact of these additional projects needs to be included in the analysis of impact of the Buck Mountain Reservoir alternative. Dredging the South Fork Rivanna Reservoir- Costs include water treatment plant improvements, pump station and intake improvements, weflancl mitigation, administrative, and land costs. The source of cost estimate for dredging was a marine contractor. The unit costs 13er cubic.yard for removal were $4-6. Tile unit costs per cubic yard for disposal were $10. VHB considered only large scale marine dredging instead of small-scale reservoir recovery, dredging, which has been utilized by many other communities with similar reservoir siltation problems. Large scale marine dredging would produce substantial turbidity, restricting the usefulness of the SFRR as a water supply during the dredging process and adversely affecting reservoir ecology. More co~t effective and less invasive alternatives are available. These derive from the use of small barges with suction/auger mechanisms which remove silt and allow it to be pumped several miles, if necessary, to reclamation areas. These barges work in as little as 21" of water and do not produce turbidity. A recent reservoir recovery project involving a 1400-acre reservoir produced a cost analysis of 67 cents ;3er c. ubic yard for removal and transfer of slit. This cost included ail labor and materials, maintenance, and depreciation of the dredge barge. It did not include costs of land acquisition for the reclamation area. Case studies show that dewatered silt can be sold for rebuilding landscapes, landfill cover, or road fill. A UVA biologist, who attended the April 20th meeting, suggested the fill could also be considerecl a valuable gardening product. A farm, presently located along the South Fork Rivanna River, produces compost. Perhaps the silt taken from the SFRR would be valuable to this operation. -17- 3, Water Conservation and Drought Management a. Mare Aggressive Water Conservation Plan Needed - For years, members of the LVVV have been advocating the adoption of a serious water conservation program for the urban area. Early in the permitting process we recommended that VHB study the v;'ater usage pafferns in our community to determine how we could reduce our water cor~umpfion, Although VHB indicated at RWSA meetings that they have had experience designing aggressive water conservation plans for other communities, they were not asked to model a comprehensive conservation plan for our community as an alternative. We have researched [he methods other communities use to reduce water consumption. By proactively retrofitting inefficient water fLxtures, promoting more efficient outdoor watering practices, and block pricing, much greater water savings can be gained than the 10% reported by VHB, b. More Aggressive Drought Management Plan Needed - Last summer, our community ironically reached an all time high in water demand ¢luring a drought perioct when total reservoir capacity was approaching the 70% level w~ere voluntary conservation would be requested, A water management plan applicable to evolving droughts should be enacted sooner than when the entire reservoir system reaches 70%. A long range more modern drought-management plan should replace the present sho~t-range plan In closing, we would like to say that we hope you share with us a commitment to presen/ing the natural environment in Albemarle County and will make every effort to involve the public in the ongoing decision-making process for a future water source. The impact of this decision will have repercussions for our county for years to come. Every stakeholder, from individual citizens to members of the Board of Supervisors and City Council, should be invited to play a role in this important process that will shape our future in such a significant way. Sincerely, Marsha Parklnson Co-Chair Natural Resources Committee Albemarle County Board of Supervisors Charlottesville City Council C01. Allan Carroll, Army Corps of Engineers Regina Poeske, E.P.A. Janet Norman. U. S. Fish an<:l Wildlife Service -18- ..... Original Message ..... From: Donna Bennett [SMTP:MoormansR@email.msn.com] Sent: Monday, May 10, 1999 12:11 PM To: Sally Thomas Subject: handouts at NRC Meeting Sally: The following are some handouts from the LoVVV NRC meeting, last Thursday. In preparation for Thurday's meeting, we were to write down areas from the VHB presentation that were of interest or concern to us. I looked into dredging costs-and called VHB for their sources. I also included > information from Mud Cat that we took from the WEB. Along the way, I > also > became interested in learning about the storage capacity vs treatment > capacity of our reservoirs. For example, I had wondered what the safe > yield > number meant relative to treatment capacity. The SWCB allows (still > permits) 5.4 mgd safe yield from SH/RM system. However, the treatment > capacity of the OH Treatment Plant is 7.7. How much can be used? The > Virginia Department of Health (¥DH) says that any available water, up to > 7.7 > mgd can be used. However, this greatly limits Beaver Creek --where the > storage capacity is 560 million gallons, the safe yield is 2.8 mgd--but > the > treatment plant can only process 1.0mgd. Because of the newspaper article > in the DP about sewer hookups and possible leasing/purchase of Camelot > pumping station in Rapidan (RSA)--I included notes from an ACSA Meeting I attended. Thus the following information is divided into three sections: 1. Treatment Capacity; 2. Dredging (water conservation and reuse); 3. Rapidan sewer expansion. Regards. Donna 1 .Treatment Capacity: Information from VA Dept of Health Operating permit, called Waterworks Operation Permit Additional information, Engineering Description Sheet (Engineering Description includes a description of raw water sources, the storage > facilities, the mechanical operation of filtering, and a list of chemicals > used for purification, etc.) :> Information from Planning Bulletin #335: Safe Yield of Municipal Surface Water Supply Systems in VA, dated 1985. (Source for VHB Reports) Sugar Hollow/Ragged Mountain Reservoir: Safe Yield (by SWCB = 5.4 mgd., Treatment Capacity of Observatory Hill Plant = 7.7 mgd. Raw Water Flow Capacity of combined reservoirs = 8 mgd -19- Additional storage capacity: 1. Storage tank near Route 29 and 250 intersection = 3 mg 2.Lewis Mountain Storage Tank = 507,580 gallons. Sugar Hollow storage capacity = 430 million gallons all of which is available for water supply Ragged Mountain storage capacity = 513.6 million gallons Beaver Creek: Safe Yield = 2.8 mgd). Treatment Capacity = 1.0 mgd. ( limited by plant capacity) Beaver Creek Storage Capacity = 615 million gallons (total water capacity equal to 1,100 gallons of which 520 million gallons are available for water supply-Bulletin) Additional Storage Capacity = 1 500, 000 tank near treatment plant 2.200,000 gallon tank near Mint Springs 3.2 million gallon tank near St. George Ave. > Totier Creek Reservoir: Scottsville: > Sage yield = 2.5 mgd > Design Basis of Treatment Plant = .25 mgd > Totier Creek Reservoir storage capacity = 182 million gallons, 120 million > available for water supply > Additional Storage = 250,000 gallon standpipe > South Fork Rivanna Reservoir: > Safe Yield =10.4 > (Safe yield of reservoir is 18.4 mgd. "Water quality models show that a > release of 8 mgd from the reservoir during dry periods would be required > SO > that water quality standards be met at the wastewater treatment plant > downstream. Were this 8 mgd release to be honored throughout the 120 day > critical drought period then the safe yield of the Soouth Fork Rivanna > Reservoir would be 18.4 - 8 = 10.4.") > Treatment Capacity = 8.0 mgd (Raw Water > Pumping Capacity 10.0 mgd with single largest pump out of service. > Filtration = 8.064. "Hence, the design capacity of this treatn~ent facility > is limited by the 4 gpm filtration rate and is equal to 8.0 mgd") > South Fork Rivanna River storage capacity = 1.76 billion gallon Storage facilities: 1. 1.0 mg tank near treatment plant 2. 5 mg tank on Pantops Mountain. North Fork Rivanna Treatment Plant: > Treatment Capacity = 2.0 mgd (Two phase distribution system). ("The > above > mentioned water distribution systems are interconnected to the system > serving the City of Charlottesville.") > > "The 2.0 mgd filter plant was originally designed with the thought that > water from Chris Greene Lake could be released to occasionally augment Iow -20- > flows in the river." > 2. Dredging: > VHB: Karen Ertl (Heads consultant team) Comments on Alternatives: > Alternatives will be presented to the regulatory agencies on May 21st. > This > should not serve as a deadline for comments; however, they should be > submitted soon after this. The regulatory agencies will pay special > attention to these comments after they have a.chance to discuss the > Alternatives. Seek information on what the community wants. Karen Ertl > gave > the following example: After the April 20th meeting, a citizen wrote > comments, concluding with strong support for reuse of water. Ms. Ertl > noted > that many communities would be opposed to reuse and that strong support > for > this innovative concept would enhance its consideration (by VHB and > agencies) as a serious alternative. > > Rapidan Partnership as an Alternative: Asked why this was considered as >an > "alternative". Her answer: Regulatory Agencies look for ways to promote > 'regional cooperation'. They looked at buying water from Rapidan and also > Rapidan buying water from RWSA. But, they discovered that buying water > would increase the demand. proposed > partnership?) > > Dredging as an Alternative: > Total: $79,300,000 (Did Rapidan Authority know about the Cost: $ 300,000 for water treatment plant improvements $76,700,000 for dredging $1,500,000 for pump station and intake improvements $ 790,000 for wetland mitigation > Other costs: $79,300,000 X 20% = $95,100,000 > $95,100,000 X 15% (Engineering, Legal and Administrative) > Land costs (300acres X $11,000/acre) = $3,300,000 Total: $112,000,000 Facility improvement costs represent increased amount of water available. More details: Type of dredging: Marine Contractors Hydraulic dredging (type used for fine sediments) National firms. Unit costs: $4-6 per cubic yard for removal Dewatering and disposal: Used localities (Denver,D.C., Fairfax) Unit costs: $10 per cubic yard for disposal. (Members asked for following quote:) U.S. GEOLOGICAL SURVEY CIRCULAR 1123 -21- > "As we approach the 21 st century, the limited water supply and established > water storage and distribution systems must be managed effectively to meet > increasing demands. Evidence abounds, however, that the era of building > large dams and conveyance systems has ended. Thus, "new" future supplies > likely will come from conservation, reuse, and improved water-use > efficiency > rather than from ambitious water-supply projects."... "the President > signed > into law the Energy Policy Act of 1992 (Public Law 102--486), which calls > for government agencies to take the lead in water-use efficiency measures > and sets new standards for water-conserving plumbing fixtures. A supply > that > has ecological and economic limits cannot be continuously expanded to try > to > meet insatiable demands. Comprehensive streamflow data are needed to > account > for the water in the Nation's hydrologic systems and to quantify the > stress > on existing supplies. Just as managers needed supply information during > the > dam-building era, they now need more comprehensive streamflow data to > assess > the effectiveness of various management options and to monitor mandated > instream flows. Recommend: Efficient use of water, Reuse, and Dredging as a way of solving Water Demand 1. Adopt 1979 RWSA Water Conservation Plan (already approved by Board) calling for Permanent Reduction in Consumption of Water. 2. Find Creative Solution to Dredging Problem in SFRR 3. Seriously consider reuse (including David Hirschman's incremental plan). Information about Mud Cat Dredging: Small scale dredging in contrast to large scale 'marine' dreging. Mud Cat is a small barge containing a suction/auger mechanism to channel silt long distances(a mile and a half, for example) to holding area. Works in as little as 21" of water Does not produce turbidity Cost for removal = $0.67 per cubic yard Dewatered silt used for rebuilding landscape of reservoir (terraced area created), taken to landfill for use in daily cover, used as roadfill by transportation department. Said to be valuable topsoil when dewatered Many communities restore lakes or reservoirs to original pristine conditions Find information (Case Histories) at www.d redge.com/cases_mudcat/water.html -22- 3. Pumping Station. ACSA Meeting: March 19, 1998 From "Other Matters Not on the Agenda" Rapidan has approached ABSA (RWSA?) about purchasing the pumping station that is located just across the county line near Greene County. Rapidan is anticipating growth in the near future (shopping center???). (For Albemarle County, a new pumping station will be needed to serve this area, > anyway-because the present station will not have the capacity to serve the > proposed growth that will take place in this sector of AC.) > Rapidan's request is under consideration at this time. Many factors come > into play as this idea is evaluated. The Four Party Agreement must be > taken > into account. Even though the station is located within AC, the other > members must agree. Also, there is the (political) question of treated > waste water crossing the county line. > Question of effluent. Rapidan is located between the Rappahannock River. > Basin and the James River Basin. If Rapidan builds its own treatment > facility (which it must do, anyway), the effluent will flow into the North > Fork Rivanna River. (Special use permit?). So, either way-whether they buy the AC existing treatment plant or whether they build their own-as far as effluent goes, the outcome will be the same. AC Growth Area. Route 785, Hollymeade, Camelot, other development potential in DGIC, 1100 A. Zoned commercial (available), proposed new elementary school, Dr. Hurt property, Advance Mills, (4000 A.), Industrical Park, W. Woods, UVA Research Park. This potential for growth must be taken into consideration now. We need to plan for the future now (even though, presently, the pumping station is working at only 1/3 its capacity). In two years, Rapidan will need pumping station. Monday, April 3, 1999. DAILY PROGRESS. "As Ruckersville sewer work ends, growth may begin" (Patrick Hickerson) Ruckersville Area Sewer Project, 10 mile line from Ruckersville Village Shopping Center to Standardsville Wastewater Treatment Plant. Plans to further increase sewer capacity-"by obtaining use of treatment plant-called Camelot-in norther AC, or by building a plant in Ruckersville." "The Rapidan and Albemarle service authories have been discussing since last year the possibility of the RSA stretching a line to the plant along the north fork of the Rivanna River...etc...." -23- Southern Environmental Law Center 201 West Main St., Suite 14 Charlottesville, VA 22902-5065 804-977~4090 Fax 804-977-1483 selcva@selcva.org May 20, 1999 Jack Marshall 3570 Brinnington Rd. Charlottesville, VA 22901 Dear Jack: We are aware that the Rivanna Water and Sewer Authority (~RWSA") is meeting on Friday with representatives from the various regulatory agencies and we therefore would like to express our specific concerns regarding the ongoing study for the future water needs of the area. While there have been two public presentations about the proposed reservoir at Buck Mountain over the past year, there has been no opportunity for feedback about the proposed project. There is a corps of citizens who are fairly well informed and concerned about the issue. We believe that it is important to obtain feedback on your plans from the community so that future studies can answer legitimate questions that have been raised. In particular, we are concerned that there has not been a concerted effort between City Council, the Board of Supervisors and the RWSA to understand the long-term ramifications of water supply planning for our community. Instead, the process appears to us to be driven by a team of consultants, who, while knowledgeable and experienced in the technical details of reservoir planning, are no substitute for community decisionmaking. Over the past several years, there have been questions raised about, among other things, the demand projections; efforts to increase existing supply and storage; the lack of a meaningful and coordinated water conservation plan, including an aggressive educational program; the importance of additional -24- Carolinas Office: 137 Est Franklin St., Suite 404 · Chapel Hill, NC 27514-3628 · 919-967-1450 DeO Sous O~ce: The Candler Building · 127 Peachtree St., Suim 605 * Atlanta, GA 30303-1800 · 404-521-9900 100% recycled paper land use planning measures to protect existing sources; additional conservation tools such as recycling or reused water; retrofit/rebat~ programs; and revisions to the rate structure to discourage wasteful use and encourage conservation. We understand full well that the environmental studies related to this project will require public participation, but we think that it is critical for the RWSA, the City and the County.to provide additional opportunities for public participation in advance of these studies. This will better involve and reflect the preferences of the community and could prevent subsequent adversarial battles as well. From our work on the James City County Reservoir and the King William Reservoir in the Tidewater region, we have learned much about the issues that will face the RWSA, and we would be happy to share the information that we have collected over the course of the last decade. We suggest that the RWSA consider a joint public hearing with' the City.and.County governing bodies, at which time the consultants could present their findings'and the public would have an opportunity to give input on the plans to date. We would be glad to discuss this further with you at your convenience. We look forward to hearing from you. Sincerely, Deborah Murray Kay Slaughter /CS CC: Regina Poeske, EPA Region III Joe Hassell, Dept. of Environmental Quality Pam Painter, U.S. Corps of Engineers ~rt Petrini, Rivanna Water and Sewer Authority Charlottesville City Council Albemarle County Board of Supervisors -25- Donna and Jim Bennett June15,1999 Arthur Petrirmi, Executive Director Rivanna Water and Sewer Authority Post Office Box 18 Charlottesville, Virginia 22902 Dear Mr. Petrinni: We are writing to provide our responses to the public meeting held April 20, 1999, during which your consultants, VHB, presented their analysis of water demand and supply alternatives tbr our area. Although the report included much valuable information, we fkel it is inadequate for our community's needs and that additional meaningful public input into the permitting process is required. As you know, we have been campaigning for several years for RWSA to release water during the summer-fall months from the Sugar Hollow Reservoir into the .begimfing of the State Scenic portion of the Moormans River below the Sugar Hollow Dam. We have persisted in this request because of our concern about ecological damage to the Moormans riverbed and related wetlands brought about by man-made cyclical drying of the river during these summer-fall dry spells, which in 1998-99 lasted 7 months. When we first approached you prior to the VHB study process, you suggested that we make our request known at a public meeting to be held by RWSA and VHB early in the permitting process--with the idea that release into the Moormans could be planned for during the subsequent period of evaluation. Because the public meeting did not take place until two and a half years later, we appealed to RWSA Board instead We were told by the Board that consideration of the subject of release of water into the Moormans could not occur until after an additiolml water supply is in place. As a consequence of this decision, no provision was made for water release into the Moormans in the VHB demand analysis for a new water supply. As you know, we have recently proposed a voluntary "proportional release" plan whereby 50% of total inflow into the Sugar Hollow reservoir, measured at weekly intervals, be released into the Moormans dtaSag the summer-fall period. Our proposal includes a cap of lmgd maximum release, and release would cease if mandatory water conservation measures were triggered by a prolonged drought. This proposal could have been easily modeled by VHB, and should have been included along with more realistic modeling of demand during drought conditions (see below). 6430 Sugar Hollow Road Phone/FAX 804-823-2636 -26- Crozet, I/.4 22932 email : M oormansR(a_)msn, corn Donna and Jim Bennett As a result of our concerns for the [ack of water in the Moormans River, we have taken a special interest in water supply and demand problems in our community. Over the past six years we have watched the level of the Sugar Hollow reservoir fall quickly at the beginning of June, with no flow over the dam for the next six months (or more). Reports last summer of the highest demand on record in our area of 14.5 mgd, during the period of time when a serious drought was evolving, show that peak summertime usage plays a major role in diverting flow from the Moormans. Yet, 'although a laudable Conservation Plan was proposed to and approved by RWSA in 1979, which would have required a permanent 10% reduction in water consumption, to date our area has not utilized any method of controlling demand. Even with the example of an unnaturally dry river bed, dramatically demonstrating the cm~sequences of RWSA's continuing to meet unchecked water demands, the same practice of meeting excessive needs of water users has been incorporated into the demand figures projected by VHB. In addition, no provision is made in these projections to allow for water release into the community's most treasured river, a river accorded the honor of State Scenic status as well as nomination and unanimous community support for Tier III designation. Our area is recognized both nationally and locally for its great natural beauty, including its typical Blue Ridge rivers. The tact that these waterways are much beloved by those who live here is exemplified by the following: Two years ago, many residents volunteered to doctunent .and assess the streams of the Rivanna River Basin, as part of a year long, EPA-sponsored, study. In addition, although Albemarle County is located far from the coast, we have adopted Chesapeake Bay Protection regulations and have been the recipient of an award for our efforts to help preserve the Bay by protecting the drainage area of the Blue Ridge. Thus, it can be seen that our community possesses a tradition of serious commitment to the preservation of our watershed areas. Yet, ironically, this concerned community has had no opportunity for meaningful public input during the two and a half year long permitting process for a new water supply. The recent public meeting, held April 20th, took place too late for true public involvement. The April meeting functioned only to convey information, not to promote open discussion of the VI-lB report. During the question period, which occurred at the end of the report, citizens asked a wide range of important questions. Some of these questions required additional information to be provided at a later time in a public setting. Unfortunately, no public meeting is scheduled to take place before the meeting with federal and state regulators. Thus, as citizens, our only opportunity to ask questions or make comments about the alternatives must unfortunately occur outside of a public forum, within the confines of this letter: 1. As mentioned earlier, we feel the demand analysis presented is too limited. Demand figures are based on historical (unregulated) usage in our community. There has been no opportunity for public debate on the important question of whether we should expect to continue to use water at current rates for the next 50 years, as is represented by demand figures. Graphs projecting water demand, but incorporating 10% and 20% reductions of water consumption, would have given the public an opportunity to study its options. A series of graphs should have been given for comparison. 6430 Sugar Hollow Road Phone/F, qX 804-823-2636 -27- Crozet, g,4 22932 ., ft email: MoorrnansR,~msn. corn Donna and Jim Bennett 2. Likewise, the presented graph projecting population growth and water demand utilized continuation of a hyperbolic growth rate in the Albemarle County service area, projected to the year 2050. Why didn't VHB also present more conservative models, representing a median between the slower growth rate that preceded 1990 and the faster growth rate since the early '90's? Graphs depicting both a more conservative population grox~a curve and more conservative water demand figures should have been offered. 3. The RWSA has utilized a graph titled "Supply and Demand" to depict the extent of a potential water deficit through the year 2050. This graph is misleading to all but the most careful observer, and it fails to contain infbrmation essential to understanding and measuring potential water supply deficits.. The graph does not depict a decrease in actual water supply through 2050. It only depicts what the "worst case" water deficit would be for each year if a most severe drought occurred in that particular year. This analysis ignores the fact that as drought conditions become more severe, more water would be conserved through voluntary and mandatory measures. Thus, the presented analysis is biased towards increasing the demand-supply disparity, because it is based on the inaccurate assumption that water usage would not Change during a severe drought. More data is needed to enable the public to make judgments on what improvements we should make in our water supply system. 4. The silting in of the South Fork Rivanna Reservoir (SFRR) is given as one cause of projected deficit of future water supply--assuming a steady rate of loss of storage capacity over time. Recovery of storage capacity in the SFRR would allow expansion of treatment capacity to 16mgd, as recommended by the James River Basin Plan. In fact, recovery of storage capacity may be critically necessary for our community if we are to avoid having to abandon this important reservoir and recreation area. However, the altemative of dredging the SFRR was presented in such an economically extreme manner as to appear unfeasible. The source of cost estimate for dredging was a large scale marine contractor. The unit costs per cubic yard for removal were $4-6; the unit costs per cubic yard for disposal were $10. Small-scale reservoir recovery dredging has been utilized effectively by many other communities to solve similar reservoir siltation problems. Large scale marine dredging would produce substantial turbidity, restricting the usefuhaess of the SFRR as a water supply during the dredging process and adversely affecting reservoir ecology. More cost effective and less invasive alternatives are available. These derive from the use of small barges with suction/auger mechanisms which remove silt and allow it to be pumped up to several miles, if necessary, to reclamation areas. These barges work in as little as 21" of water and do not produce turbidity. A recent reservoir recovery project involving a 1400 acre reservoir produced a cost analysis of 67 cents per cubic yard for removal and transfer of silt. This cost included all labor and materials, maintenance, and depreciation of the dredge barge. It did not include costs of land acquisition for the reclamation area. This is about 5% of the cost presented by VHB. Case studies show that dewatered silt can be sold for rebuildin.l~ landscapes, landfill cover, or road fill. A UVA biologist, who attended the April 20u' meeting, suggested the fill could also be considered a valuable gardening product. A 6430 Sugar Hollow Road Phone/FAX 804-823-2636 -28- Crozet, ~'/t 22932 email: MoormansR(~msn. com Donna and dim Bennett farm, presently located along the South Fork Rivanna River, produces compost. Perhaps the silt taken from the SFRR would be valuable to this operation. 5. We commend VHB's creative suggestions for reuse of water--including piping effluent from the Moores Creek Treatment Plant to the Mechums River. The idea~of reuse of water in the Mechums in tandem with the idea of utilizing the Mechums River Pumping Station to transport water to Ragged Mountain reservoir represents a further solution for allowing additional biological purification of currently highly treated wastewater and for creating greater storage capacity. The Ragged Mountain Reservoir is presently dependent on a very limited drainage area. Other reuse concepts might also be utilized--such as reuse on a smaller scale, for example, within individual developments and neighborhoods. 6. Several organizations requested that a comprehensive Water Conservation Alternative be researched and presented. As mentioned above, our community does not have an effective, modem water conservation plan. Although VHB indicated at RWSA meetings that they have had experience designing water conservation plans ~br other communities, they were not asked to model a comprehensive plan for our community as an alternative. We feel that by proactively retrofitting inefficient water fixtures, promoting more efficient outdoor watering practices, and block pricing, much greater water savings can be gained then the 10% reported by VHB. 7. Drought Management. Our Comprehensive Plan states that ground water and surface water are interdependent, and all water users have a stake in the preservation of natural water resources. For this reason, our whole community needs a more comprehensive and thoughtful drought management plan. Ironically, last summer, public water consumption reached an all time high during a drought period when total reservoir capacity was approaching the 70% level where voluntary conservation would be requested. We need a more modern style of long range planning for drought management. Mandatory conservation should occur sooner than when the entire reservoir system reaches 70%. Implementation of such a plan would significantly alter the demand analysis. Another drought management problem exists, as well. The Sugar Hollow/Ragged Mountain Reservoir system (sometimes serving more than half the water consmners) is supplied by a 20 square mile drainage area. The SFRR is supplied by a 260 square mile drainage area. This disparity is not planned for during times of iow rahrfall. A more comprehensive drought management plan should be designed which deals with specific characteristics of individual reservoirs. In summary, we feel that important community issues are not being addressed as part of the planning for a new water supply and that meaningful public input into the permitting process has yet to occur. Although we have written this letter as individuals, we represent the point of view of many in our area who feel we have an obligation to future generations to preserve exceptional rivers, like the Moormans, and exceptional natural regions, like Albemarle County. Preservation of important natural resources can only come about as a result of careful planning where all members of the community urban, suburban, and rural--work together to help shape the future. The presentation of 6430 Sugar Hollow Road Phone/FAX 804-823-2636 -29- Crozet, gA 22932 email: Moormar~'R(~msn. corn Donna and Jim Bennett Preliminary Alternatives focussed on meeting the future demands of one sector of our community, the public water users. Significantly, the report did not take into consideration the vital role communit-y-wide stewardship must play in this planning process. Sincerely, Donna and Jim Bennett CCi Albemarle County Board of Supervisors Charlottesville City Council Col. Allan Carroll, Army Corps of Engineers Regina Poeske, E.P.A. Janet Norman, U. S. Fish and Wildlife Service Joe Hassell, D.E.Q. 6430 Sugar Hollow Road Phone/F/LY 804-823~2636 -30- Crozet. V~4 22932 email: MoormansR!~msn. corn WILLIAM McDONOUGH + PARTNERS 410 E Water Street Charlottesville VA 22902 804 979 1111 Fax 804 979 1112 June3,1999 Mr. Jack Marshall Chair, Board of Directors Rivanna Water and Sewer Authority P.O. Box 18 Charlottesville, VA 22902-0018 Re~ Rivanna Water and Sewer Authority Water Supply Project Dear Jack, Thank you for the opportunity to submit written comments on the water supply alternatives outlined in the Public Information Meeting of April 20 1999. As you 'know, I was the co-chair of the Rivanna River Basin Roundtable from 1996 - 1998. The Roundtable is citizen group appointed by the Thomas Jefferson Planning District Commission, which is charged with envisioning the future of the watershed. We spent over a year collecting information and data on the historical and current conditions of the streams and rivers in the watershed and published a report on our findings, conclusions and recommendations in early 1998. One of the things that we realized as we pursued our charge concurrently with the Thomas Jefferson Sustainability Council is that this is a community that wishes to define and guide its future on the basis of carefully considered and articulated core values and principles. From the public presentation, it appears that the Water Supply Project is not based on such a definition of values. I would posit that'there are four principles with wide currency within our community that ought to form the b~;.s for your efforts. I would not for a moment want to suggest that you do not share these values, because I believe that you do. What I encourage is a public discussion of what our starting point is and how we should measure success. Let me suggest the following principles: 1. Preserving the biological vitality of our rivers and streams is a fundamental responsibility of our ste~vardship of natural systems. Optimum in-stream flow in our rivers is a starting point for discussions about water withdrawal. The word optimum is carefully chosen here - minimum in-stream flow is not a noble goal. Why would we want to define the standard for the health of our aquatic X:',BIN~US E RSkRKP\W P\LTR99U M060399. DOC .2. ecosystems as the minimum necessary for the system to function.9 There is so much that we do not know about ecosystem function. It would be hubris to suggest that we can accurately define a minimum quantity of flow that would preserve and support healthy, vital and resilient surface waters. What if we are wrong.'? We should study the range of variability of the primary surface waters and err on the side of allowing more water to course through the system rather than less. The seasonal deprivation of the Moormans River is unacceptable. We must restore its historical flows and take all steps necessary to assure that we do not rely on depriving other rivers in the future for our own inefficient water management practices. We shauld use only such ...notable water as is necessary and return it to our rivers and streams in a form that is healthy and ready for reuse. We are prisoners of a misguided technology that combines human waste with vast quantities of potable water causing us to expend significant sums of money to remove the waste prior to release. Over time, this practice will diminish, in favor of more sensible and less resource intensive solutions. While we work towards this inevitable change in technology we should aggressively "mine our own inefficiencies" to create new quantities of available water by using only what is necessary in the course of our activities. As a community we need to wean ourselves from wasteful landscape practices that involve the planting of climatically inappropriate species that require irrigation with potable water. We need for the Authority to provide education and leadership in water conservation. The water that we release is, by most accounts, very clean. It achieves the. standards for "fishable and swimmable" water and is close to achieving a standard for potable water. We count on the biological processes themselves for this final cleansing. The river serves us well in this capacity. We should make use of its capacity for biological cleansing as a component of our water supply strategy. 3. We should llve Our annual rainfall of 45" is sufficient for the current and future water needs in this region. We should be able to husband this res.ource in such a way as to assure that our needs are met without going beyond the Rivanna River watershed for supplemental water. We currently live within these limits and should continue to do so as a model for those in our neighboring watersheds. We 'know that our watershed has inherent characteristics that offer challenges in this regard. Our region's geology does not provide us with abundant resources of stored ground water. These need to be reserved for those who live outside the reach of the public water supply. Our region's topography does not give us many good opportunities to impound water efficiently, that is to say that our shallow valleys with gradual slopes require us to use an inordinate land area for a small storage capacity. Understanding these realities ,,,,'ill cause -32- X:\B INXU SE RS\RK PXW P\LT R99kJ M060399. DOC us to look to more creative solutions for meeting our water needs while assuring the vitality of our aquatic ecosystems. Going down the path of inter-basin transfer is not one of these creative solutions. It represents a selfish attitude of"getting there first" - staking our claim and letting our neighboring regions fend for themselves. 4. Leveraging our investment in public infrastructure is fundamentally sensible in the short and long term. We now know that the same land use practices that have squandered topsoil for generations are also responsible for silting in our reservoi?s. In the case of the South Fork Rivanna Reservoir, based on today's replacement cost, this careless siltation has cost our community an average of $170,000 per year. If provided with the proper information, our community would make the smart choice to leverage its assets by investing in reasonable alternatives such as vegetated buffers to slow this senseless waste. The Authority could provide valuable leadership in framing this discussion. All reasonable options for extending the useful life of this reservoir should be implemented at once. In the process of evaluating the alternatives presented to the Authority, 1 find the primary regulatory criterion, to cause the minimum environmental consequences, to be an instructive yardstick and one sympathetic with these principles. If one were to accept these principles and to seriously attend to this regulatory criterion, what course is suggested? I would submit the following course, in this order: 1. Institute aggressive water conservation now. This is the most environmentally benign solution available to us and fits well within our principles. I was disappointed that the consultants dismissed this strategy by setting their sights too low. We should aim for a 50% reduction in water use and invest as seriously in this strategy as we would in one of thc engineering solutions that are favored in the presentation of options. I would propose that a real study of conservation be done. At the risk of misstating some of the numbers due to lack of available information, let me outline a possible scenario. - If we aim to save 6 mgd (half of our water use) and are willing to invest at the rate of $4.00/g (roughly the lowest rate for the new dam and reservoir alternatives), we ~vould have a pool of $24,000,000 available for this venture. Nowhere have I been able to find the precise number of households served by the Authority nor the mix of commercial to residential use. However, if we have 36,000 households (I doubt it is this high), we could spend $750/household to invest in state-of-the-art toilets, shower heads, faucets, washing machines and dishwashers. Buying in bulk and establishing an efficient network of plumbers who focussed on retrofitting households, we could replace most of the wasteful -33- X:\BIN\USERSLRKP\WP\LTR99~JM060399.DOC fixtures within the Authority's boundaries for this incremental sum, while creating dozens of jobs. How would we encourage people to pa~rticipate? The first step would be public education, then the carrot and stick. The carrot- it's free, the stick- at the end of two years, institute a stepped rate schedule with the current rate charged for half of the current use (around 50 gallons/person/day). Then institute "conservation pricing" for any greater use. I do not know what the right formula is for a program like this. I would expect a lively debate in the course of developing the program, but first we have to start the discussion. By eliminating a retrofit program from consideration and dismissing the resulting tepid water conservation option as ineffective, your consultants are not moving us forward in this venture. With the on-going growth in this region:and the number of residences under construction, stringent standards should be applied through the building codes for all permitted construction. Here is the best part ... no regulators and we can start immediately. Every gallon we save recharges the Moormans River and builds a buffer against the kind of low rain fall that we have had in the past year. 2. Leverage our investment in the South Fork Rivanna Reservoir. The Authority should work with Albemarle CountY to institute land use controls that slow and eventually stop the siltation of the reservoir. Looking at the cost to all of us of our inaction on this front, we can hardly afford not to be making this investment as well. This initiative will take some time so we should start right away to stabilize stream banks, minimize impervious surfaces and establish healthy stream side vegetated buffers. . I strongly endorse the alternatives for increasing the height of the dam at the South Fork Rivanna Reservoir (SFRR) to salvage some of its dwindling capacity. These are inexpensive alternatives and extend our collective investment in this resource. Your consultants also suggested that this could be a relatively quick alternative to implement, which is also valuable. Some members of our community have investigated the technology and economics of reservoir recovery, as it might be applied to the SFRR. Their research suggests that there is a significantly less expensive alternative for dredging to the one priced by your consultants. I would encourage you to have your consultants investigate small hydraulic auger dredges that remove sediment in a non-turbidity-producing manner. This technology has been available for over 10 years and deserves careful consideration. I would be very interested in reading an assessment of the applicability of this technology to the SFRR. 3. Invest in ~vater reuse. There is no question that water reuse will play a significant role in our water planning strategy over the 50-year horizon of your study. It would be smart to start now. Our water -34-- X:\BIN',USERS\RKP\W r~LTR99~J M060399.DOC use plan currently assumes that the biological processes in the Rivanna River will provide the final cleansing of the effluent from the Moore's Creek water treatment plant. We should use that to our advantage. There is something inherently elegant about reusing the same water over and over again ... forever. This is the sustainable water solution of the future. It should be possible to balance our retainage and releases to restore the flow downstream of all impoundments to the natural range of variability in a serious reuse scenario. In addition to considering a pumpback to the Meechums River, I am also interested in the notion introduced by one of the staff of the Authority - to use the two reservoirs at Ragged Mountain as final treatment sites in a reuse strategy. Over time, if our needs continue to grow, we may find that we ha¥'e several options for sites ,'o inco¢orate inta the pumpbac 'k/reuse model. Thank you for taking the time to work your way through these thoughts. Of all people, you know how complex this issue is and how deserving of our careful consideration. I must say that I was disappointed that your consultants in their presentation and analysis exhibited a strong bias for heavy-handed engineering solutions, primarily focussed on new dams and reservoirs. We need to be much more creative than that. This community has no shortage of creativity and will. We need to move beyond old discredited ideas that are based on the premise that "if brute force isn't working, you are not using enough of it". We need to move to elegant solutions based on an appreciation for and understanding of the inherent logic and beauty of natural systems. Please provide the leadership to move us all in this direction. If you do, you will find a majority of this community solidly behind you. I would be delighted to meet to discuss this further at your convenience. Sincerely, Russell Perry, AIA Managing Partner Cci Art Petrini, RWSA Col. Allan Carroll, US Army Corps of Engineers Regina Poeske, USEPA Region 3 Janet Norman, US Fish and Wildlife Service City Council of the City of Charlottesville Board of Supervisors of Albemarle County -35- X:\BIN~U SERS'~RKP\WP',LTR99'd M060399.DOC ~OUNDTA1~L~. DATE: July 8, 1999 TO: Charlottesville City Council Albemarle County Board of Supervisors FROM: League of Women Voters of Charlottesville/Albemarle County Rivanna River Basin Roundtable Water Policy and Water Supply Planning The League of Women Voters and the Rivanna R/ver Basin Roundtable advocate sound water policy and full public participation in water decisions that will impact our community, far into the fhture. Regarding the Water Supply Planning process now underway by the Rivanna Water and Sewer Authority (RWSA), we believe that this process is so important that the ele~cted officials of Albemarle County and the City of Charlottesville should be setting basic policy in this matter. Public participation over the past few years in numerous water forums, summits, and committees, in the RWSA process, and at the Water Supply Plan public meeting of April 20, 1999, suggest a high level of informed citizen interest and concern. Therefore, we urge the County, the City and the RWSA, jointly, to in/t/ate a ser/es of meetings to promote public education, dialog and deliberation on this important issue. We believe that there w/Il be broad interest in and appreciation for this opportunity for public discourse. We propose thc following sessions to be held as soon as scheduling permits, but certainly no later than early September, 1999: 1. An open joint City Council/Board of Supervisors work session with RWSA presenting their water supply and demand analyses and the potent/al alternatives they have identified to meet their projected future demand Additionally, service, educational and conservation groups, and other informed parties that represent the broad spectrum of water use and interest in the Basin should be invited to make concise, informed presentations. 2. A second open meeting to be held after a period of time to allow our elected officials to study the information presented and to solicit input from their constituents. This meeting would give the elected officials an opportun/ty for questions and answers with the RWSA and for a joint discussion of water supply and use strategies. 3. A public hearing for further input by the community on water policy and supply issues. -36= gO'd £g:6 66, 9'[ In£ O08S-96g-l;'Oe:Xe-~ ),,,<-,r,-, The Water Supply Planning process is proceeding at a del/berate pace. We see no reason that the proposed meetings would interrupt or disrupt the process underway. Conversely, now that the RWSA has identified numerous alternatives for consideration, we feel that this is an/deal t/me t'or the public and its mpmsentat/ves to be engaged in the dialog. We ask that you /nitiate this dialog in an expectit/ous manner. Since the Water Supply Planning process w/Il continue for an undefined time, we also suggest that you establish a joint City/County and Regional water oversight commission or task force. This would aIIow the integration of broader water issues with the task of providing an adequate potable water supply for the public: service area. We thank you for your attention to these requests, and offer any assistance you would find helpful in organizing the proposed informational meetings and/or identifying important participants. Respectfully yours, Ruth Wadlington and Sandy Snook Co-Presidents, League of' Women Voters Charlottesville and Albemarle County Arthur Bulger, Ph.D. Chairperson, Rivanna River Basin Roundtable -37- £O'd £5:6 66, £l ln£ 008S-96C-~8:xe~ Raw Water Supply Facility Permitting Supply Analysis Albemarle County and City of Charlottesville Prepared for Rivanna Water & Sewer Authority Prepared by O'Brien & Gem Engineers, Inc. ~r-/~/Vanasse Hangen Brustlin, Inc. DRAFT October 1997 fredva:30502~jraphics',cover~30502cov, pm5 l~aw Water Supply Facility Permitting 'O Water SupplY Analys s Albemarle County/City of Charlottesville, Virginia Prepared for Prepared by Rivanna Water and Sewer Authority Charlottesville, Virginia O'Brien & Gere Engineers 8201 Corporate DriVe, Suite 1000 Landover, Maryland 20785 and · Vanasse Hangen Brustlin, Inc. 477 McLaws Circle, Suite 1 Williamsburg, Virginia 23185 October 1997 O'Brien & Gere Engineers, Inc. Table of Contents Executive Summary Introduction ............................................................................................................................ System Description ................................................................................................................ 2 South Rivanna WTP ................................................................................................................... 2 Observatory WTP ......................................................... ' .............................................................. 2 North Fork Rivanna WTP ........................................................................................................... 2 Methodology ......................? .................................................................................................... 5 Gauging Station Bata ................................................................................................................. 5 Surrogate Watershed Selection .................................................................................................. 6 Safe Yield Analysis ................................... ~ .......................................................................... 11 Rivanna Reservoir .................................................................................................................... 1.1 Sugar Hollow/Ragged Mountain Reservoir System ................................................................. 13 North Fork Rivanna River Intake .............................................................................................. 16 System-Wide Safe Yield ..................................................................................................... 18 References ............................................................................................................................. 20 i Table of Contents \\willva~projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Ina. FigUres Figure No. Description Page No. Urban Service Area .................................................................................. 3 1930 River Flows ...................................................................................... 8 RWSA System-Wide Safe Yield .............................................................. 19 ii Table of Contents \\willva~projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. Executive Summary Vanasse Hangen Brustlin, Inc. (VHB) has been authorized by the Rivanna Water & Sewer Authority (RWSA) to prepare a raw water supply study to evaluate the future water needs of the RWSA's Urban Service Area which includes the City of Charlottesville and surrounding areas. O'Brien & Gere Engineers, Inc. serves as a subcontractor to VHB on various aspects of the raw water supply study. Among the initial efforts as part of this study are tasks to: (1) estimate the current and future safe yield of the existing raw water supply system and, (2) project future water demand through the year 2050. A comparison of safe yield and demand projections will enable the RWSA to better understand whether and when it may face a water deficit, and the magnitude of any such deficit. Subsequent studies will include an analysis of alternatives to address any water deficit. Alternatives to be evaluated will include, but will not necessarily be limited to, new sources of supply, water conservation programs, demand control measures, and options to restore or increase the safe yield of existing sources. This report summarizes the results of a raw water safe yield review of the existing RWSA Urban Service Area system as it has historically operated. This system includes the (1) Rivanna Reservoir, (2) Sugar Hollow/Ragged Mountain Reservoir system, and (3) North Fork Rivanna River Intake. For purposes of this analysis, "safe yield" is defined as the maximum raw water yield that can be supplied consistently over the long term. It is estimated by examining hydrologic data for as long a time period as possible and then calculating the probable maximum yield of the raw water supply resource during the most severe drought, also referred to as the "critical period". Previous safe yield estimates conducted for the same water supplies used differing techniques and drought periods to estimate safe yield. For example, the recent Urban. Area Raw Water Management Plan (Black & Veatch, 1995) used synthesized flow records simulating the period 1942 - 1991, and particularly the drought of 1954 to estimate the yield of the Rivarma Reservoir. The Report on Water Works System Charlottesville, Virginia (Polglaze & Basenberg, 1959) used the 1930 drought to · predict the safe yield for the Rivanna Reservoir. The Safe Yield of Municipal Surface Water Supply Systems in Virginia Planning Bulletin #335 (Virginia State Water Control Board, March 1985) used the 1953-54 critical period to estimate safe yield of the Sugar Hollow/Ragged Mountain system. Executive Summary \\witlva\projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. Methods employed for this analysis included a review of United States Geological Survey (USGS) stream gage data for numerous gauging stations in the region. This data was used to select representative hydrologic data and to identify the critical periods for all three water supply sources noted above. System-wide safe yield evaluations were 'performed for the RWSA Urban Service Area system based on the 1930 drought, which was found to be the critical period for each of the water supply systems (the Rivanna Reservoir, Sugar Hollow/Ragged Mountain Reservoir system, and the North Fork Rivarma River). The system-wide safe yield was estimated by adding the safe yield estimates for each component of the system. As no data exist to directly evaluate the effect of the 1930 drought on the Sugar HolloW/Ragged Mountain reservoir system, estimates of safe yield based on two surrogate watersheds were used. The estimated safe yield of the water supply system is currently 11.9 to 12.6 mgd. This range in safe yield results from uncertainty regarding the 1930 safe yield of the Sugar Hollow/Ragged Mountain system. As siltation reduces storage volume in the reservoirs, this safe yield will decrease over time. Safe yield for the system in Year 2050 is estimated to be 4.5 mgd to 4.8 mgd. Current and future safe yield estimates for the existing raw water supply system and for each component of the system are Summarized below. RWSA Current And Future System-Wide Safe Yield Estimates Source Current Safe Year 2050 Safe Yield Yield Rivanna Reservoir 7.2 mgd 0 mgd Sugar Hollow/Ragged Mtn. 4.1 to 4.8 mgd ¢) 3,9 to 4.2 mgd ¢) North Rivanna River Intake 0.6 mgd 0.6 mgd Total System 11.9 to 12.6 mgd 4.5 to 4.8 mgd (1) Range corresponds.to uncertainty regarding the 1930 drought event. Executive Summary \\willva~projects\30502\obrien&gere\Watersupply1097 E 0 0 0 0 0 0 0 0 0 0 0') 0 "- (plStu) Ple!A e:[eS Je:l.e~ O'Brien & Gere Engineers, Inc. Introduction Vanasse Hangen Brustlin, Inc. (VHB) has been authorized by the Rivanna Water & Sewer Authority (RWSA) to prepare a raw water supply study to evaluate the future water needs of the RWSA's Urban Service Area which includes the City of Charlottesville and surrounding areas. O'Brien & Gere Engineers, Inc. serves as a subcontractor to VHB on various aspects of the raw water supply study. Among the initial efforts as part of this study are tasks to: (1) estimate the current and future safe yield of the existing raw water supply system and, (2) to project future water demand through the year 2050. A comparison of safe yield and demand projections will enable the RWSA to better understand whether and when it may face a water deficit and the magnitude of any such deficit. Subsequent studies will include an analysis of alternatives to address any water deficit. Alternatives to be evaluated will include, but will not necessarily be limited to, new sources of supply, water conservation programs? demand control measures, and options to restore or increase the safe yield of existing sources (i.e. dredging). This report summarizes the results of a raw water safe yield review of. the existing RWSA Urban Service Area system as it has historically operated. This system includes the (1) Rivanna Reservoir, (2) Sugar Hollow/Ragged Mountain Reservoir system, and (3) North Fork Rivanna River Intake. For purposes of this analysis, "safe yield" is defined as the maximum raw water yield that can be supplied consistently over the long term. It is estimated by examining hydrologic data for as long a time period as possible and then calculating the probable maximum yield of the raw water supPly resource during the most severe drought, also referred to as the "critical period". 1 Introduction \\willva \projects \30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. System Description The Rivanna Water and Sewer Authority Urban Service Area system includes three water treatment plants (WTP): (1) South Rivanna WTP, (2) Observatory WTP, and (3) North Fork Rivanna WTP. These treatment plants receive raw water from a water supply system which includes reservoirs and a river diversion. Major system components are shown in Figure 1. South Rivanna WTP The South Rivanna WTP withdraws raw water from the Rivanna Reservoir which is located on the South Fork of the Rivanna River. The reservoir has a usable volume of 880 million gallons (MG) and a drainage area of 261 mi2. However, since 18 mi2 of the Rivanna Reservoir drainage basin flows to the Sugar Hollow ReServoir ~see Observatory WTP discussion below), a drainage basin size of 243 mi (261 mi2 minus 18 mi2 ) has been used to calculate safe yield at the Rivanna Reservoir. I Observatory WTP The Observatory WTP is located in the City of Charlottesville and withdraws water from the "Upper" and "Lower" Ragged Mountain reservoirs via an 18 inch raw water pipe. These reservoirs were evaluated as one with a total drainage area of 1.8 mi2 and a usable volume of 514 MG. The Observatory WTP also withdraws from the Sugar Hollow Reservoir via another 18 inch raw water pipe. The Sugar Hollow Reservoir is located at the confluence of the north and south fork of the Moorman's River, has a drainage area of 18 mi2 and a usable volume of 360 MG. It is located entirely within the drainage basin of the Rivanna Reservoir and can supply raw water to the Ragged Mountain Reservoir by way of a weir overflow box that interconnects the system. II North Fork Rivanna WTP The North Fork Rivanna WTP withdraws water from the North Fork of the Rivanna River via a river intake. The drainage area for the river at this point is 121 mi2 . That number does not include the drainage area located above Chris Greene Lake, an impoundment on Jacobs Run. Jacobs Run is a tributary of the North Fork Rivanna River located upstream of the RWSA's intake. The drainage area above Chris Greene 2 System Description \ \willva\ projects \30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. Lake was not included in these calculations because the impoundment historically has been used for recreational purposes and it has not released water during times of severe drought. Thus, this drainage area has not contributed to the safe yield of the North Fork Rivanna River Intake. A full evaluation of using Chris Greene Lake and its upstream drainage area for water supply purposes will be undertaken as part of the analysis of alternatives available to the RWSA. 4 System Description \\wiltva\projects\$0502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. Methodology Gauging Station Data Based on a review of available documents, 'it appears that recent safe yield calculations ( Black & Veatch, 1994 and 1995) were not based on the 1930 drought, an event which, in O'Brien & Gere's experience, has been the most limiting in estimates of the safe yield of nearbY water supplies. However, during the1930 drought event, gauging stations were not in operation at the WTP intake locations which are the focus of this analysis. In order to estimate the effects of the 1930 drought on the water supply system as previously described, streamflow data were obtained from nearby gauging stations in the area which were in service during 1930. These gauging stations were evaluated to determine the suitability of each for use as surrogates .for the Rivanna River, the Moorman's River, and the North Fork Rivanna River. The search for compatible gauging stations encompassed the following counties in Virginia which are topographically similar and are in close proximity to the Rivanna System: Amherst Albemarle Greene Appomattox Fluvanna Madison Nelson Louisa Culpeper Bucki.ngham Orange Rappahannock Table 1 shows the gauging stations which were active in these counties during the 1930 drought event. The gauging station which was active on the Rivanna River below Moore's Creek (near Charlottesville) during the 1930 drought was moved upstream to a point near Earlysville near the Route 29 bridge downstream from the Rivanna Reservoir dam. Data are available from this location for the period from 1/1/53 to 12/31/57. 5 Methodology \ \willva\projects\30502\obrien&gere\watersupply1097 O'Brien & Gere Engineers, Inc. Table 1. Available gauging stations (1930 drought) Gauging Station/River/Location County Dates of Available Data Drainage Area Rivanna River below Moore's Creek (later moved to a location near Earlysville) Slate River near Arvonia Tye River near Roseland and Lovingston North Anna River near Doswell Rapidan River near Culpeper and Rapidan Albemarle Buckingham Nelson Caroline Culpeper 10/1/25-3/31/34 (No data for some months) and (1/1/53- 12/31/57) 4/1/26-9/30/93 (No data from 1935-36) 10/1/27-9/30/93 (Station moved in 1938, no data for some months of that year) 4/1/29-9/30/88 4/1/25-9/30/93 (Station moved downstream in 1930) 507 mie (216 mi2 @ Earlysville) 226 mi2 68 mi2 441 mi2 472 mi~ SurrOgate Watershed Selection In determining the safe yield of the water supply system, supplies to the three WTPs have been analyzed separately. Rivanna Reservoir Due to the fact that 18 mi2 of the Rivanna Reservoir drainage basin flows to the Sugar Hollow Reservoir, which feeds the Observatory WTP during a drought, the Rivanna Reservoir safe yield has been calculated using a drainage basin size of 243 mi2 (rather than 261 mi2). Data are available for the 1930 drought at a gage on the Rivanna River downstream of the existing reservoir (Rivanna River below Moore's Creek). These data were used to calculate a safe yield for the reservoir, and a surrogate watershed (Slate River near Arvonia) was selected to confirm this calculation. There are two drought periods for which historical flow data are available at all of the gauging stations described in Table 1: the 1930's drought of record and the 1950's drought which was used in previous studies. To assess the suitability of potential surrogates, average yields were calculated and compared for each of these watersheds. The results of the average yield calculations for each historical period are shown in Table 2. 6 Methodology \ \wilIva\projects\30502\obrien&gere\watersupply1097 O'Brien & Gere Engineers, Inc. Table 2. Average yield at potential Rivanna River surrogates Gauging Station/River/Location County Avg. Yield, period of 1011129-3/31134 ' (cfs/mi2) Avg. Yield, period of 1/1/53-12/31/57 (cfs/mi2) Rivanna River below Moore's Creek (10/1/29-3/31/34) and near Earlysville (1/1/53-12/31/57) Slate River near Arvonia Tye River near Roseland and Lovingston North Anna River near Doswell Rapidan River near Culpeper Albemarle 0.77 0.81 Buckingham 0.74 0.75 Nelson 1.41' 1.93 Caroline 0.69 0.67 Culpeper 0.73 0.84 The average yield of the Rivanna, Slate, and North Anna rivers did not vary significantly for the two periods (within each basin). The Slate and Rapidan rivers have yields most similar to the Rivanna River. More detailed review of the data for the specific drought period between May and November of 1930, suggests that the Rapidan River had lower yields than the Rivanna during the drought. (A comparison of daily flow data is provided in Figure 2). The Rapidan River flow also recovered more slowly from this drought. Daily data for the Rivanna and Slate rivers compare more favorably. Because of the repeatability of the average yield data and the similarities of flow patterns through the drought, separate safe yield calculations were carried out using both the Slate and Rivanna gauging station data. Sugar Hollow/Ragged Mountain Reservoir System The Sugar Hollow and Ragged Mountain Reservoirs have been evaluated as one system of reservoirs with a drainage area of 19.8 mi2. Since no streamflow data are available for the Moorman's River during the 1930 drought, two surrogates were selected to use in safe yield calculations for the Sugar Hollow/Ragged Mountain system. Since the Sugar Hollow Basin lies entirely within the Rivanna River watershed, the Rivanna River flows should closely mimic those in the Moorman's River. The Rivanna River was therefore selected as one surrogate for the Moorman's River. In order to evaluate other potential surrogates, the flow yield (flow volume/drainage area) at the gauging stations was compared with that of the Moorman's River during a period in which data are available for all gages. The Slate River, which had a yield most similar to that of the Moorman'~, was also selected as a surrogate. Daily flow data for the surrogates were adjusted for differences in drainage area and flow yield, 7 Methodology \\wiltva\projects\30502\obrlen&gere\watersupply1097 o ('!uJ 'bs/$~o) MOI--I 0 ~ 0 O'Brien & Gere Engineers, Inc. and these adjusted data were used in a safe yield analysis based on the 1930 drought. In order to verify the use of the Slate River, the evaluation was repeated using 1954 data from the Slate River gage, and the results were compared to the existing 1954 data from the Moorman's River gage. This comparison revealed that simply using the Slate River as a surrogate for the Moorman's River results in a significant overestimate of the documented 1954 flows. This difference was used to develop a correction factor for use in estimating safe yield. No data are available for the Moorman's River (source for the Sugar Hollow Reservoir) during the 1930 drought. Therefore, surrogate watersheds, for which 1930's data are available, were selected for estimating the safe yield of the Sugar Hollow/Ragged Mountain system during this drought event. Since the Sugar Hollow Basin lies entirely within the Rivanna River watershed, the Rivanna River flows should closely mimic those in the Moorman's River. To determine the similarities between the Moorman's River and the rivers which had gauging stations during 1930, available data for the North Fork of the Moorman's River (1952-1963 and 1982-1983) were compared with data for the same periods from these other rivers. Although there is no period for which data are available from both the Rivanna River gauging station and the Moorman's River gauging station, the Rivanna River was selected for use as a surrogate because the Rivanna River watershed includes the Sugar Hollow basin. The average yields of the Moorman's River and the other potential surrogates are shown on Table 3. Table 3. Average yield of potential Moorman's River surrogates' Gauging County Avg. Yield, Station/River/Location (cfs/mi2) North Fork of the Moorman's River near White Hall Slate River near Arvonia Albemarle 1.50 Buckingham 0.92 Tye River near Roseland Nelson and Lovingston 2.13 North Anna River near Caroline 0.84 Doswell Rapidan River near Culpeper 1.02 Culpeper The Rivanna River is not included because there is no period for which data is available from both the Rivanna River station and the Moorman's River station. 9 Methodology \ \ willva\projects \30502\ obrien&gere\w a tersupply 1097 O'Brien & Gere Engineers, Inc. Of the rivers analyzed, the Rapidan should be removed from consideration because, as determined in the analysis and shown on Figure 2 of the Rivanna Reservoir, the Rapidan flows did not mimic recorded flows in the Rivanna River during the 1930 drought (the Moorman's River Basin is located within the Rivanna Watershed). Of the remaining rivers, none appear to have an average yield closely corresponding to that of the Moorman's River. Therefore, the Slate River data, which indicate a yield closest to that of the Moorman's River and closely resembled the Rivanna River Basin during the 1930 drought, was used to estimate safe yield for the Moorman's River. The Slate River data were adjusted with a yield factor of 1.50/0.92 to correct for differences in yield. North Fork Rivanna River As previously noted, the North Fork watershed area is approximately 121 mi2 excluding the portion above Chris Greene Lake. The safe yield calculation has been carried out based on the 1930 drought using the same data set from the Rivanna River as was used for the Rivanna, Sugar Hollow and Ragged Mountain reservoirs (Rivanna River below Moore's Creek Gauge). Data from the. North Fork Rivanna River near Proffit, Virginia have also been used to calculate the safe yield of the system and thus verify previous work. Recent studies of the North Fork Rivanna River have relied on data from a gauging station on the North Fork of the Rivanna River (at the Route 606 crossing) near the WTP intake. This gage is an excellent surrogate but was not in place during the 1930 or the 1954 droughts. In order to estimate the safe yield of this source during the 1930 drought, O'Brien & Gere modeled the system using data from the Rivanna River gage which was active during the 1930 drought (Rivanna River below Moore's Creek). 10 Methodology \ \ willva \projects \30502 \obrien&gere \ watersul~l~ly1097 O'Brien & Gere Engineers, Inc. Safe Yield AnalYsis Rivanna Reservoir Estimated safe yields were calculated for the Rivanna Reservoir using adjusted data from two gauging stations: the Rivanna River below Moore's Creek, and the Slate River near Arvonia. Daily flow data for each of the rivers were adjusted for differences in drainage area. The watershed area used for the Rivanna River at the reservoir was 243 mi2, a value used in the Interim Memoranda for the Urban Raw Water Management Plan (Black & Veatch, 1994). This watershed area excludes 18 mi of the ~ivanna Watershed which supplies the Sugar Hollow Reservoir. It was assumed in the Black & Veatch report that the Sugar Hollow Reservoir would supply water to the Ragged Mountain Reservoir during drought conditions. No adjustment of data for flow yield was necessary, as the yield values were fairly similar for both the Rivanna and Slate rivers. A 1994 bathymetric survey found a usable storage volume of 880 mg and a siltation rate of 13.01 mg/year. For current (1997) safe yield calculations, the Rivanna Reservoir storage volume was assumed to be 841 MG. This value represents the volume between the spillway elevation (382 ft.) and the lowest water intake gate elevation (367 ft.). The available volume of 841 MG represents approximately 63% of the total reservoir volume of 1333 MG (178 million cubic feet). To estimate the future safe yield of the reservoir, continued loss of storage volume due to siltation was considered. In the December, 1959 Report on Water Works System Charlottesville, Virginia by Polglaze & Basenberg, an evaporation factor of 44 inches per year was applied. This corresponds to a loss of 1.28 mgd from the Rivanna Reservoir. The estimated current safe yield for the 1930 drought was calculated by determining the date of drought initiation (the day that the net reservoir inflow began to decrease according to the daily flow records) and applying daily withdrawal rates and evaporation losses from that date such that all available storage volume is emptied at the time daily inflows begin refilling the reservoir. Results of the safe yield calculations are shown in Table 4. 11 Safe Yield Analysis \ \willva \pr ojects",30502 \ obrien&gere\Wa tersupply 1097 O'Brien & Gere Engineers, Inc. Table 4. Current Rivanna River Unadjusted Safe Yield Gauging station Estimated watershed current safe yield (unadjusted) Rivanna River below Moore's Creek Slate River near Arvonia 15.2 mgd 15.0 mgd As expected, the Rivanna River and Slate River results are quite similar. O'Brien & Gere believes that the 15.2 mgd value is the best estimate of unadjusted safe yield (based on the 1930 drought) for the current reservoir volume, because the drainage area Of the Rivanna River below Moore's Creek Gauge includes the Rivanna Reservoir drainage area and is considered a slightly better surrogate. In determining available withdrawals for the South Fork Rivanna WTP, this value has been adjusted to incorporate the minimum flowby currently used for purposes of maintaining water quality on Moore's Creek (downstream of the Moore's Creek Wastewater Treatment Plant). This flowby is not mandated by a Minimum Instream Flow requirement. Discussions with Virginia Department of Environmental Quality (VDEQ) personnel indicate that the 8.00 mgd currently used is based on an old modelling effort (from the 1970's) and suggest that additional modelling could be performed as part of a study to establish a more accurate estimate. Until such a study is complete, 8 mgd has been used as the best existing estimate of the minimum flowby required to maintain water quality. Therefore, the current safe yield for the Rivanna Reservoir is 8 mgd less (7.2 mgd) than the unadjusted 15.2 mgd estimate based on the 1930 drought. The safe yield (based on the 1930 drought) was projected for the future using reduced reservoir volumes as projected in the 1994 Black & Veatch report. Black & Veatch used a bathymetric survey of the reservoir to evaluate the amount of previously available reservoir volume which has been displaced by siltation and to predict the future displacement of storage. The estimated annual storage loss due to siltation was 13.01 MG/year. Siltation is caused by the settling of solids which are carded into the reservoir by streams and rivers. Because the streams and rivers typically enter the reservoir in the shallows, and because settling will occur soon after entering the quiescent reservoir, the siltation typically occurs in areas which are above the lowest intake (rather than at depths which are not usable storage volume). A cursory review of the bathymetric survey report supports the assumption that the loss of volume is primarily in areas above the elevation of the lowest intake gate. Therefore, the reservoir volume would be reduced by 729 MG by the year 2050 (56 years x 13.01 MG/yr.) to 151 MG. The safe yield calculation was repeated using this reservoir volume and applying 1930 drought flow data from the gauging station at the Rivanna River below Moore's Creek. This calculation predicts an unadjusted safe yield of 6.6 mgd in 2050, using the Rivanna River Gauge 12 Safe Yield Analysis \ \willva\projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. as a surrogate and 7.7 mgd in 2050 using the Slate River ,Gauge. Reducing this for the flow-by of 8 mgd provides an estimated safe yield of 0 mgd. As anticipated, this is lower than the 3.9 mgd safe yield calculated for the Rivanna Reservoir in the year 2040 using 1954 drought data as reported in the 1994 Black & Veatch report. Current estimated safe yield for the Rivanna Reservoir, based on Rivanna River data from the 1930 drought, is 7.2 mgd. This value is substantiated by evaluating data from the Slate River, which resulted in an estimated safe yield of 7.0 mgd. Since the 8 mgd flowby is greater than the 1930 drought flows, the estimated safe yield for the year 2050 is 0 mgd. Sugar Hollow/Ragged Mountain Reservoir System To determine the likelihood that the 1930 drought was more severe than · the 1954 drought, minimum instream flows were compared for the four gauging stations which collected data during both events. Minimum 30- day average instream flows at these gauging stations are shown on Table 5. Table 5. Comparison of average instream flows for 1930 and 1954 droughts 1930 Minimum 1954 Minimum 30-Day Average 30-Day Average Gauging Station Instream Flow Instream Flow 9.9 cfs State River near Arvonia Tye River near Roseland and 6.0 cfs Lovingston North Anna River near Doswell 8.4 cfs 22.9 cfs 10.8 cfs 8.1 cfs Rapidan River near 7.7 cfs Culpeper and Rapidan 12.5 cfs Rivanna River not shown because its gage was not active in 1954. At three of the four gauging stations, the 1930 drought was significantly more severe than the 1954 drought, and at the fourth station the droughts were similar in magnitude. This evaluation suggests that the 1930 drought was probably as severe, or more severe, than the 1954 drought in the Moorman's River Basin. However, no data are available to directly calculate the safe yield of the Sugar Hollow/Ragged Mountain Reservoir system based on the 1930 drought. In the absence of such direct data, O'Brien & Gere calculated an upper 13 Safe Yield Analysis \ \ willva\ projects \30502\ obriert&gere\ Watersupply 1097 O'Brien & Gere Engineers, Inc. limit for the reservoir system's safe yield based on the less-severe 1954 drought (verifying previous studies) and an approximation of the probable safe yield during the 1930's event as described below. Estimated safe yield for the Sugar Hollow/Ragged Mountain Reservoir system during 1930 was calculated in several steps. First, the Slate River flow data from 1930 were used as one surrogate for the Moorman's River. Next, the Rivanna River flow data from 1930 were used as a surrogate. A 19.8 mi2 drainage area was used for the reservoir system which consists of 18 mi2 for Sugar Hollow and 1.8 mi2 for the Ragged Mountain Reservoir. These values were taken from the Safe Yield of Municipal Surface Water Supply Systems in Virginia Planning Bulletin #335 (Virginia State Water Control Board, March 1985). The 44 inches/year evaporation factor (discussed above) corresponds to a loss of 0.6 mgd from the Sugar Hollow/Ragged Mountain. System. The State Water Control Board used 1953-54 streamflow data for the North Fork of the Moorman's River to calculate a safe yield of 5.4 mgd. O'Brien & Gere repeated this evaluation using the same data, and the same reservoir volume. A safe yield of 4.8 mgd was calculated. The 'difference is apparently a result of the evaporation factor. A study of the dam at Sugar Hollow Reservoir has recently been performed to determine the best operat!ng elevation for the spillway crest. Based on this study, RWSA has decided to operate the Sugar Hollow Reservoir with crest gates at elevation 975. A recently conducted hydrographic survey determined the volume of the Sugar Hollow Reservoir to be 360 MG (with crest gates at elelvation 975). Reducing this volume by the estimated siltation rate of 1.49 MG/year for three years resulted in a 1997 volume of 356 MG. The Ragged Mountain Reservoirs have a total volume of 514 MG. The Ragged Mountain/Sugar Hollow system was evaluated as one reservoir with a total volume of 870 MG. Analysis Using Slate River Gauging Station An additional adjustment was made to the 1930 Slate River data for differences in the average yield of the two rivers by applying a yield factor of 1.50/0.92 (based on comparable historical data for the two rivers, as discussed above). This analysis resulted in preliminary safe yield estimates for the Ragged Mountain/Sugar Hollow system, based on Slate River data, of 6.0 mgd. To assess the validity of the 6.0 mgd estimate, the methodology applied to the 1930 data was applied to the 1954 data and compared to actual recorded flows. The safe yield was calculated using Slate River flow data from 1953-54, adjusted to the Moorman's River by watershed size and yield, and using the 944 MG reservoir volume (the volume prior to loss of 70 MG of storage). This calculation resulted in a safe yield estimate of 8.5 mgd for the Sugar Hollow/Ragged Mountain Reservoir system during the 1953-54 drought event. Existing Moorman's River 14 Safe Yield Analysis \\willva\projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. flow data indicate a safe yield of only 4.8 mgd. The methodology plainly is overestimating the flows in the Moorman's River. Accordingly, a correction factor was estimated by comparing the safe yield calculated using the recorded flows in the Moorman's River during the 1950's drought (4.8 mgd) with the safe yield calculated using the Slate River data corrected for drainage area size and yield (8.5 mgd). By applying this correction factor (4.8/8.5) to the previously calculated safe yield based on the 1930's drought (6.0 mgd), a safe yield estimate of 3.4 mgd is obtained. Analysis Using Rivanna River Gauging Station The Rivanna River has a drainage area of 507 mi2 at the gauging station versus '19.8 mi2 for the Sugar Hollow Reservoir. Therefore, a correction factor of 19.8/507 was used in this analysis. This analysis resulted in preliminary safe yield estimates for the Ragged Mountain/Sugar Hollow system, based on Rivanna River data, of 4.1 mgd. Based on the above, O'Brien and Gere believes that 4.1 mgd should be used for the present safe yield estimate of the Sugar Hollow/Ragged Mountain reservoir system. However, this report shows the 4.8 mgd estimate from the 1954 drought to indicate, the upper end of the potential safe yield. This range reflects the uncertainty in the 1930's hydrologic data. No flow-by requirement is currently applicable to this reservoir system. Therefore, no reduction in safe yield has been employed and it is assumed that. the entire basin flow may be used for water supply purposes. Based on that assumption, the numbers shown above are estimates of reservoir safe yield at present. The estimated current safe yield of the Sugar Hollow/Ragged Mountain Reservoir system based on the 1930's drought is 4.1 mgd. Safe yield estimates are shown on Table 6. The 1954 safe yield (4.8 mgd) and the 1930 Slate River safe yield (3.4 mgd) are also shown in this table for informational purposes. 15 Safe Yield Analysis \\wilIva\projects\30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. Table 6. Sugar Hollow/Ragged Mountain Current Safe Yield Estimates Reservoir volume 1930 1954 1930 Rivanna Moorman's Slate River River River analysis analysis analysis* 944 MG (prior to any 4.3 mgd siltation) 4.8 mgd 874 MG (including siltation through t997) 3.4 mgd 4.1 mgd 4.5 mgd * adjusted from Polglaze & Basenberg estimates for evaporation The reservoirs were constructed with a volume of 944 MG. Recent studies indicate that this volume has been reduced by 70 MG due to a recent landslide and general siltation. To account for projected loss of storage in estimating future safe yield, calculations were carried out using various reservoir volumes and applying all three methodologies described above (1930 Rivanna River Data, Slate River Data, and 1954 Moorman's River Data.) A 1.49 MG/year siltation rate (70 MG loss of storage over the 47-year reservoir life) was applied for projections of future safe yield of the Ragged Mountain/Sugar Hollow Reservoir system. The results of these calculations are shown in Table 7. Table 7. Ragged Mountain/Sugar Hollow future safe yield estimates (year 2050) Reservoir volume 1930 Rivanna 1954 1930 River Moorman's Slate Riveranalysis analysis River analysis 794 MG 3.1 mgd 3.9 mgd 4.2 mgd North Fork Rivanna River Intake Estimated safe yields were calculated for the North Fork Rivanna River using adjusted data from two gauging stations: the Rivanna River below Moore's Creek and the Slate River near Arvonia. Daily flow data for each of the rivers were adjusted for differences in drainage area. The watershed area of the North Fork Rivanna River at the WTP intake (exclusive of the Chris Greene Lake portion of the watershed) is 121 mi2. This value was used in the "Technical Memoranda for the Safe Yield of the North Fork Rivanna Water System" (Black & Veatch, 1995). 16 Safe Yield Analysis \ \willva \projects\30502 \obrien&gere \Watersupply 1097 O'Brien & Gere Engineers, Inc. In determining available withdrawals for the North Fork Rivanna WTP, this value may need to be adjusted for a minimum instream flow requirement. There is currently no minimum instream flow (MIF) but it is possible that one may be imposed in the future. The estimated safe yield of the North Fork Rivanna River at the WTP intake, during the 1930 drought, was calculated to be 0.6 mgd using the Rivanna River Gauge and 0.7 mgd using the Slate River Gauge. Because no storage volume is required for a run of the river intake (like the one at the North Fork Rivanna WTP), the estimated future (year 2050) safe yield at the North Fork Rivanna River Intake source is unchanged from the estimated current safe yield (0.6 mgd). If the existing Chris Greene Lake and its drainage area were used for water supply purposes, this safe yield would be increased, The amount of that increase in safe yield would depend on the balance struck between use of Chris Greene Lake for recreational purposes, an its use for water supply purposes. O'Brien & Gere will fully evaluate the potential safe yield that may result from use of Chris Greene Lake for water supply purposes in the upcoming analysis of alternatives. 17 Safe Yield Analysis \ \witlva\project$ \30502\obrien&gere\Watersupply1097 O'Brien & Gere Engineers, Inc. System-Wide Safe Yield System-wide safe yield evaluations have been performed for the Rivanna Water and Sewer Authority Urban Service Area system based on the 1930 drought, which was found to be the critical (drought) period for the Rivanna, Sugar Hollow/Ragged Mountain Reservoirs and the North Fork Rivanna River. The system-wide safe yield has been estimated by adding the safe yield estimate for each component of the system. As no data exist to directly evaluate the effect of the 1930 drought on the Sugar Hollow and Ragged Mountain Reservoirs, estimates of safe yield based on two surrogate watersheds have been used. The estimated safe yield of the current system is 11.9 to 12.6 mgd depending on uncertainty regarding the 1930 safe yield of Sugar Hollow/Ragged Mountain. As siltation reduces storage volume in the reservoirs, this safe yield will decrease. Safe yield for the system in Year 2050 is estimated to be 4.5 mgd to ,$.8 mgd. Current and future safe yield estimates for the system and foreach component of the system are shown in Table 8 and on Figure3. Table 8. RWSA current and future system-wide safe yield estimates Source Current Safe Yield Year 2050 Safe Yield 7.2 mgd 0 mgd Rivanna Reservoir Sugar Hollow/Ragged 4.1 to 4.8 mgd (1) 3.9 to 4.2 mgd (4) Mountain North Rivanna River 0.6 mgd 0.6 mgd Total System 11.9 to 12.6 mgd 4.5 to 4.8 mgd (1) Range for uncertainty regarding the 1930 drought event 18 System-Wide Safe Yield \ \willva\projects\30502\obrien&gere\Watersupply1097 E 0 0 (p6tu) ple!A ej. es Je~,e~ ~et:! 0 0 0 CO 0 0 0 0 0 0 ~- O'Brien & Gere Engineers, Inc. References BLack & Veatch, 1994. Interim Memoranda for the Urban Raw Water Management Plan, November 1994, t 16 pp. Black & Veatch, ~1995 (Revised). Urban Raw Water Management Plan Summary Report, Hevised August 1995, 24 pp. F:'olglaze. and Bas..enburg, 1959. Report on Water Works System, Charlottesville, virginia, vecemDer 1959, 101 pp. Virginia State Water, Control Board, 1985. Safe Yield of Municipal Surface Water Supply SysTems, Virginia Planning Bulletin #335. 20 References \ \ willva \projects \30502\obrlen&gere \Wa~rsupply1097 Draft Rivanna Water and Sewer Authority Preliminary Alternatives [] [] [] Public Information Meeting April 20, 1999 RIVANNA WATER SEWER AUTHORITY PRELIMINARY WATER SUPPLY ALTERNATIVES Increase in Estimated Unit Cost Alternative Safe Yield (mgd) Cost ($) (S/gallon) Aquifer Storage & Recovery 0 N/A N/A Conventional Withdrawal of Groundwater 0.1 1,200,000 12/gallon James River Withdrawal at Scottsville 15 72,000,000 4.80/gallon Rivanna River Withdrawal 4.7 17,800,000 3.79/gallon Mechums River Withdrawal 0.2 850,000 4.25/gallon Mechums River Withdraw. + Conversion of Ragged Mtn. to Pumped Storage Reservoir 10 47,000,000 4.70/gallon Construct Dam on Buck Mountain Creek 14.4 57,000,000 3.96/gallon Construct Dam on North Fork Rivanna River 15.4 79,000,000 5.13/gallon Construct Dam on Preddy Creek 6.4 91,000,000 14.22/gallon Construct Dam on Mechums River Near Lake Albemarle 13.3 68,000,000 5.11/gallon Construct Dam on Mechums River ',lear Midway 5.6 26,000,000 4.64/gallon Construct Dam on Buck Island Creek 15 118,000,000 7.87/gallon Construct Dam on Moormans River 11.6 106,000,000 9.14/gallon No Action 0 Comments \\WillvaLProjects\30502\Sheets~Altemative Comments 3\Sheet 3 4/12/99 @ 9:15 AM AssumptiOns All pricing is in current dollars 0anuary 1999) Costs are based on an "order of magnitude" estimate Cost for property acquisition based on $11,000/ acre ($8,000/acre for wetland mitigation) Cost estimates include: 15% engineering/legal/administrative fees 20% contingency Costs for water distribution system improvements are not included Transportation costs are not included except where noted otherwise Wetland mitigation costs are included in the cost estimate and are based on approximate wetland impacts Cost estimates do not include costs associated with mitigation for threatened/endangered species and cultural resources 7Q 10 or 30% mean annual flow is adequate to meet agency requirements Pipeline alignments are conceptual and for cost estimating purposes only Peaking factor of 1.5 used to size' the waterworks facilities where appropriate Operation and maintenance costs not included 8 willva\ 30502ho, p65 Dredging South Fork Rivanna River Reservoir Dredging of bottom sediments in the middle and upper reaches of the reservoir approximately three times through 2050, each time returning the reservoir to it's original storage capacity. Requires dewatering and disposal of dredged spoil. Includes 3 mgd expansion of South Fork Rivanna water treatment plant, raw and finished water pump stations. · Increase in 2050 safe yield- 10 million gallons per day' · Estimated cost- $112 million through 2050 Locating suitable sites for dredge spoil disposal poses challenge Approximately 100 acres of land needed per dredging event · Temporary water quality impacts · Direct impact to 5 acres of wetlands; additional impacts to shallow water habitat · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements willva\ 30502ho.p65 Decrease Sediment Load into South Fork Rivanna, River Reservoir Implementation of watershedprotection measures within the South Fork Rivanna River Reservoir watershed which encompasses over 260 square miles. May include construction of regional stormwater management ponds on target watersheds, the effects of a new Water Protection Ordinance adopted in 1998, and possible expansion of stream buffer requirments. · Increase in 2050 safe yield for regional stormwater management ponds alone- __ million gallons per day · Increase in 2050 safe yield for ordinance alone- ~ million gallons per day · Increase in 2050 safe yield for both regional ponds and expansion of stream buffer requirements- ~ million gallons per day · Estimated cost- $.__ million for regional ponds · Estimated cost for implementation and expansion of stream buffer requirements- $ · Target sites suitable for regional stormwater management ponds · Environmental benefits to water quality · Approximately ~ acres of wetland impacts for regional ponds · May require surveys for threatened/endangered species and cultural resources · Assumed approximately 50% sediment removal efficiency for regional ponds based on preliminary results of Lickinghole Creek basin monitoring 10 willva\ 30502ho.p65 Decrease Sediment Load into South Fork Rivanna' River Reservoir (continued...) Assumed __% removal' of sediment load for watershed protection measures implemented as a result of the watershed protection ordinance No anticipated residential displacements Impacts to private property in the form of reduced agricultural land 11 willva\ 30502ho.p65 Revise Downstream Release Regime at SOuth Fork Rivanna River Reservoir Presently, the release regime at South Fork Rivanna River Reservoir would consist of augmenting natural streamflows during severe drought conditions. The revised release scenario would be operated such that the natural stream- flow would not be augmented during severe drought conditions. Includes installation of stream gages on major reservoir tributaries as well as controls/ valves on the existing dam. · Increase in 2050 safe yield- 3.8 million gallons per day · Estimated cost- $386,000 · Minimal environmental impacts over long term · Downstream habitat assessment may be required · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 12 willva\ 30502ho.p65 4' Crest Controls on South Fork Rivanna Dam Addition o/four-foot crest controls to increase the normal pool elevation/rom 382feet to 385feet. Requires replacement of Route 67~ bridge over Ivy Creele and acquisition of land around the reservoir. Assumed no cliscbarge of fill mate- rial into jurisdictional areas and therefore no requirements for wetland mitiga- tion. · Increase in 2050 safe yield- 6 million gallons per day ~ · Estimated cost- $~.~ million · Increases useable storage volume by 600 million gallons · Increase in storage volume reduces rate of system storage loss over time · Purchase of approximately 70 acres of land surrounding reservoir · Requires alteration to existing FERC license exemption · Approximately ~/acres of wetlands inundated by new pool · James spiny Mussel previously identified in vicinity; would need to examine potential impacts · Possible impact to one previously identified archaeological site (eligibility not determined)~ additional archaeological surveys may be required · Potential indirect impact to one previously identified historic structure (eligibility not deter- mined); additional architectural surveys may be required · Possible displacement of 2 residences · Possible ira)acts to private property around reservoir such as docks, boat houses, etc. 13 willva\ 30502ho.p65 8' Crest COntrols on South Fork Rivanna Dam Addition of eight-foot crest controls to increase the normal pool elevation from 382feet to 390feet. Requires replacement of Route 676 bridge over Ivy Creek and acquisition of land around the reservoir. Includes 4.5 mgd expansion of South Fork Rivanna Reservoir intake, plant and pump stations. Assumed no discharge of fill material into jurisdictional areas and therefore no require- ments for wetland mitigation. · Increase in 2050 safe yield- i 1 million gallons per day · Estimated cost- $14.7 million · Increases useable storage volume by 1,300 million gallons · Increase in storage volume reduces rate of system storage loss over time · Purchase of approximately 170 acres of land surrounding reservoir · Requires alteration to existing FERC license exemption · Approximately 39 acres of wetlands inundated by new pool · James Spiny Mussel previously identified in vicinity; potential effects undetermined · Possible impact to one previously identified archaeological site (eligibility not determined); additional archaeological surveys may be required · Potential indirect impact to one previously identified historic structure (eligibility not determined); additional architectural surveys may be required · Possible displacement of 2 residences · Possible impacts to private property around reservoir such as docks, boat houses, etc. 1 4 willva\ 30502ho,p65 South Fork Rivanna River Reservoir as Pumped Storage Reservoir High flow sleimming from the Rivanna River into the South Forle Rivanna River Reservoir. Includes a new pump station and new intake on the Rivanna River just downstream of the confluence of the North and South Forks of the Rivanna River. The drainage area of the Rivanna River at the intake is approximately 450 square miles. No withdrawal to occur when flow in the Rivanna River drops below 30% of mean annual flow. · Increase in 2050 safe yield- 0 million gallons per day · Insufficient flow exists in Rivanna River when South Fork Rivanna River Reservoir has available volume to refill · No storage available in reservoir during non-drought conditions · Sedimentation into reservoir results in continued reduction in available storage · Minimal wetland impacts · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 15 willva\ 30502ho.p65 5' Drawdown of Chris Greene Lake to Supplement North Fork Rivanna RiVer Convey water from Chris Greene Lake to the North Fork Rivanna water treat- ment plant during severe drought conditions to supplement the North Fork Rivanna River water system. Would be limited to a 5-foot drop of pool elevation, Includes a 3.2 mgd expansion of the North Fork Rivanna finished water pump station and water treatment plant. Chris Greene Lake is a 52-acre impoundment with storage volume of 334 million gallons. · Increase in 2050 safe yield- 3 million gallons per day · Estimated cost- $7.4 million · Would require coordination to address prior use of Land and Water Conservation Funds · Currently designated a water supply protection area · Currently used for swimming, fishing and boating · Frequency of occurrence: approximately once every decade · Possible impacts to existing recreational activities during drawdown · Anticipate minimal environmental impacts · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 16 wiilva\ 30502h0,p65 20' DrawdoWn of Chris Greene Lake to Supplement North Fork Rivanna River Convey water from Chris Greene Lake to the North Fork Rivanna water treat- ment plant during severe drought conditions to supplement the North Fork Rivanna River water system. Would allow for a maximum drawdown of 2O feet. Includes a 7.2 mgd expansion of the North Fork Rivanna finished water pump station and water treatment plant. · Increase in 2050 safe yield- 5.5 million gallons per day' · Estimated cost- $14 million · Would require coordination to address prior use of Land and Water Conservation Funds · Greater drawdown could have significant recreational impacts · Potential impacts to fish populations · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 17 willva\ 30502ho.p65 Use Chris Greene Lake as Pumped Storage Reservoir High jIow skimming from the North Fork Rivanna River into Chris Greene Lake via a river intake and pump station. During drought conditions, raw water would be conveyed from Chris Greene Lake to the North Fork Rivanna water treatment plant. No skimming to occur when flow in the Rivanna River drops below 30% of mean annual flow. · Increase in 2050 safe yield- 0 million gallons per day ' Insufficient flow in North Fork Rivanna River when Chris Greene Lake has available volume to refill · No available storage in reservoir during non-drought conditions · Minimal wetland impacts · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 18 willva\ 30502no.1:)65 Dredge Sugar Hollow Reservoir Dredging of landslide debris and bottom sediments in the reservoir once through 2050. Requires disposal of dredge spoil but minimal dewatering. During drought conditions, the additional volume would be released to the South Fork Reservoir or diverted to the Ragged Mountain Reservoirs. · Increase in 2050 safe yield- 0.1 million gallons per day · Estimated cost- $7.4 million · Locating suitable sites for dredge spoil disposal poses' challenge due to topography · Approximately 25 acres of land needed for disposal · Temporary water quality impacts · Direct impact to 2 acres of wetlands; minimal impacts to shallow water habitat · No anticipated impacts to cultural resources and threatened/endangered species · No residential displacements 19 willva", 30502ho.p65 Pumpback to South Fork Rivanna River Reservoir (Indirect Re. Use) Pumpback of treated effluent from the Moore's Creek waste water treatment plant to the Mechums River to augment flow into the South Fork Rivanna River Reservoir. lncludes a 10.5 mgd expansion of the S. Fork Rivanna River Reservoir pump stations and water treatmentplant, a new 22.5 mgd pump station at Moore's Creek, new filters at the Moore's Creek treatment plant, a new 22.5 mgd booster pump station, and a new 36-inch pipeline along 1-64 for a distance of approximately 12.5 miles. · Increase in 2050 safe yield - 15 million gallons per day · Estimated cost - $56 million · Will require the acquisition of land along the pipeline corridor · Anticipate dose scrutiny by Virginia Dept. of Health · Approximately 2 acres of wetland impact · James Spiny Mussel previously identified in the vicinity; would need to examine potential impacts · Impacts to cultural resources not known; additional surveys may be required · No anticipated residential displacements 2O willva\ 30502ho.p65 Water Conservation Development and implementation of a long term water conservation program consisting of plumbing fixture changeout (without retrofit program), public education/awarenessprograms. Short term savings resulting from outdoor watering restrictions and mandatory conservation are addressed under drought management. · Reduction in Demand - 1.5 mgd (Residential) due to plumbing ftxture changes through the year 2050 · Reduction in Demand - 0.08 mgd (Commercial and Industrial) · Reduction in Demand - 0.17 mgd (Residential) due to water conservation public awareness and education · Cost of plumbing fLxture changeout - $0 · Cost of Public Education/Awareness program - $50K per year ($2.5 million through 2050) · No major permanent restrictions on outdoor water use assumed Savings estimates based on the following assumptions: Fixture Type Current Type Assumed Use Toilet 3.5 gallons 1.6 gallons per flush per flush Showerhead 5.0 gallons 2.5 gallons per minute per minute 21 wiltva\ 30502ho. P65 Drought Management Development and implementation of a drought management plan. Plan in- cludes mandatory water conservation and a ban on outdoor water use. Plan also includes a drought management operating scenario for the RWSA existing water supply facilities. Supply side techniques include synergistic operation of existing facilities, reduction or elimination of downstream releases, and diver- sion from other uses. 1.8 mgd reduction in demand due to mandatory water conservation and limitations on outdoor water use during summer drought · Indoor water consumption reduced by 5% · Outdoor water consumption reduced by 25% · 0.6 mgd reduction in demand for similar restrictions during winter drought · ! mgd increase in safe yield due to system wide drought management 22 willva\ 30502ho.p65 Leak Detection and Meter Calibration Leak Detection and Meter Calibration programs are implemented by the Albemarle County Service Authority (ACSA) and the City of Charlottesville as the distributors of finished water to the end user. Both currently have active leak detection and meter calibration efforts underway. · No specific reduction in demand can be directly attributed to this alternative · Financial incentive exists for leak detection · Meter calibration and changeout is revenue neutral · Overall documented system losses indicate that entire system is operating within generally accepted limits · Leaks are detected and responded to early using billing monitoring and written notification system · Meter change out is being done systematically by both the ACSA and City · Meter calibration results from1998 indicate acceptable meter performance 23 willva\ 30502ho.p65 Growth Management Attempt to slow population growth in the Albemarle County portion of the Urban Service Area to reduce future demand for public water supply Potential means include further restricting the size of Urban Service Area, increasing minimum lot sizes, and actively discouraging industrial, commercial, or business development within the Urban Service Area. Could decrease 2050 demand by as much as 1.5 million gallons per day Costs would be significant but cannot reasonably be qUantified Reducing population growth 5~rithin the Urban Service Area would likely result in increased growth in surrounding rural areas on well and septic systems May be politically infeasible as it reverses Comprehensive Plan and policy of two decades attempting to guide growth into Urban Service Area and away from rural areas Secondary impacts would include dispersed development outside the Urban ServiCe Area, requiring construction and maintenance of infrastructure improvements to roads and utilities · Transportation and safety impacts could be expected 24 wiltva\ 30502ho.p65 Regional Cooperation Interconnection between the Rivanna Water and Sewer Authority water supply system and the Rapidan Service Authority system in order to provide additional water supply to the Rapidan Service Authority. The Rapidan Service Authority projects additional demand for approximately 2.0 to 3.0 mgd of water through the year 2050. Connection would be via pipeline approximately 3.5 miles long at the closest approach of the two service areas, along U.S. Route 29 south of Ruckersville. · Increase in 2050 demand- 3 million gallons per day Estimated cost- $~ The Rapidan Service Authority is considering a variety of short term and long term solutions to their future water needs Potential environmental impacts not yet determined 25 willva\ 30502ho.p65 Aquifer Storage and Recovery Storage of treated water in a suitable aquifer during times when available wa- ter supply exceeds demand and subsequent recovery of water during drought conditions. · Increase in 2050 safe yield - 0 million gallons per day · Unsuitable geologic conditions: presence of subsurface rock with Iow transmissivity · Not feasible 26 willva\ 30502ho,p65 Conventional Withdrawal of Groundwater Installation of 15 shallow groundwater wells and piping water to the existing South Fork and North Fork water treatment plants (WTP): 6 wells in the vicinity of North Fork WTP and 9 wells in the vicinity of South Fork WTP. Includes instal- lation of wells, pump, piping and land acquisition. Groundwater is typically of good quality but has the potential for high iron. Increase in 2050 safe yield - O. 1 million gallons per day Estimated cost- $1.2 million Minimal environmental impacts No residential displacements are anticipated 27 willva\ 30502ho.p65 James River Withdrawal at Scottsville Withdrawal of water from the James River at Scottsville with a new 22.5 mgd river intake, raw waterpump station, a new 36-inch pipeline to the South Fork water treatment plant, and a 10.5 mgd expansion of the South Fork Rivanna water treatment plant and finished water pump station. Alternatively, an option was considered which included a new 22.5 mgd river intake, raw and finished water pump stations, and a new water treatment plant at Scottsville with 36- inch pipeline along Route 20 to Charlottesville. The costs were essentially equiva- lent. The option presented provides water treatment at the South Fork Plant. · Increase in 2050 safe yield o 15 million gallons per day · Estimated cost- $72 million · Requires acquisition of a 25' wide easement along entire pipeline length · Approximately 5 acres of wetland impacts · Impacts to threatened/endangered species not known; additional surveys may be required · Potential impact to archaeological resources along James River; additional archaeological surveys may be required · Potential impact to previously identified Scottsville Historic District; additional surveys related to historic structures may be required · No anticipated residential displacements 28 willva\ 30502ho. D65 Rivanna River Withdrawal Withdrawal of water from the Rivanna River near Glenmo're Country Club. Includes a new 7 mgd river intake, raw and finished water pump station, water treatmentplant, booster pump station, and a new 24-inch/16-inch pipeline from the finished water pump to the existing 16-inch main along Route 250 which currently serves the Village of Rivanna. Increase in 2050 safe yield - 4.7 million gallons per day ' Estimated cost- $17.8 million Potential water quality concerns Moore's Creek waste water treatment plant discharge is located more than 5 miles upstream Requires acquisition of a 25' wide easement along entire pipeline length Approximately 2 acres of wetland impacts Impacts to threatened/endangered species not known; additional surveys may be required Impacts to cultural resources not known; additional survey for cultural resources may be required 'o No antiCipated residential displacements 29 wiiiva\ 30502ho,p65 Mechums River Withdrawal Skimming of high flows from the Mechums River at the site of the abandoned intake and pump station near Lake Albemarle and pump to the Ragged Mountain Reservoirs. Includes rehabilitation of the river intake, pump station and ancillary features, as well as access road improvements. · Increase in 2050 safe yield - 0.2 million gallons per day · Estimated cOst- $850,000 · Insufficient flows in Mechums River during severe drought conditions · Useful only when there are droughts in two successive years · Minimal impacts to wetlands ~,Impacts to cultural resources or threatened/endangered species not known; additional surveys may be required · No anticipated residential displacements 30 willva\ 30502h0.~65 Mechums River Withdrawal and Conversion of Ragged Mountain to Pumped Storage Reservoir Skimming of high flows from the Mechums River into Ragged Mountain Reser- voirs by rehabilitating and expanding the abandoned intake and pump station on the Mechums River to 10 mgd. This option is combined with raising the dam for Lower Ragged Mountain Reservoir by 50' creating a normal pool elevation of 700' with a surface area of 275 acres and storage capacity of 2,800 million gallons. Results in inundation of existing dams. Option also includes new 24- inch pipeline, 15 mgd intake on Ragged Mountains, and 8 mgd expansion of Observatory water treatment plant and pump station. · Increase in 2050 safe yield - 10 million gallons per day · Estimated cost - $47 million · Requires purchase of approximately 125 acres of additional land Approximately 5 acres of wetlands inundated by increased pool elevation at Ragged Moun- tain Reservoirs Impacts to cultural resources or threatened/endangered species not known; additional surveys may be required · . One potential residential displacement 31 willva\ 30502ho,p65 Construct Dam and Reservoir on Buck Mountain Creek Construction of a dam and reservoir on Buck Mountain Creek 1.5 miles up- stream of the confluence of Buck Mountain Creek and the S. Fork Rivanna Reser- · voit. Includes: new 21.6 mgd intake, 9. 6 mgd expansion of the existing S. Fork Rivanna intake, raw water pump station, water treatment plant and finished water pump station. Normal pool elevation of the new reservoir 480feet with surface area. of 670 acres and storage capacity of 5,242 million gallons. Drain- age area of reservoir 38 square miles. · Increase in 2050 safe yield - 14.4 million gallons per day · Estimated Cost - $57 million · Assumes minimum flowby = 7Q10 based on short affected stream segment · Does not require purchase of additional land · Approximately 59 acres of wetland impacts · Potential impacts to previously identified populations of James Spiny Mussel · Direct impact to 2 previously identified historic structures (eligibility not determined) · Potential indirect impacts to 4 previously identified historic properties (eligibility not determined); additional cultural resource surveys necessary · Potential displacement of 1 residence 32 willva\ 30502ho.p65 Construct Dam and Reservoir on North Fork Rivanna River Construction of a dam and reservoir on North Fork Rivanna River 2 miles west of the North Fork Filtration Plant. Includes:new 23 mgd intake and pump sta- tion, 11 mgd expansion of the S. Fork Rivanna Reservoir intake, pump stations and treatment plant, and a new 36-inch pipeline from the North Fork Rivanna pump station to the South Fork Rivanna River Reservoir. Normal pool elevation of new reservoir 490feet with surface area of 1,057 acres and storage capacity of 10, 059 million gallons. Drainage area of reservoir 63 square miles. · Increase in safe yield - 15.4 million gallons per day · Estimated cost - $79 milliOn · Will require land acquisition · Assumes minimum flowby = 30% of mean annual flow · Approximately 72 acres of wetland impacts · Impacts to threatened/endangered species not known; additional surveys may be required Direct impacts to 4 previously identified archaeological sites (eligibility not determined); additional archaeological surveys required Potential indirect impacts to 3 previously identified historic properties (eligibility not determined); additional architectual surveys necessary · Potential displacement of 2 residences 33 willva\ 30502ho.p65 Construction of Dam and Reservoir on Preddy Creek Construction of a dam and reservoir on Preddy Creek 2.5 miles northeast of the North Fork Rivanna water treatment plant. Includes a new 9. 6 mgd intake struc- ture, raw water pump station, water treatment plant, finished water pump sta- tion, and a new 24-inch pipeline. Normal pool elevation of reservoir 460feet with surface area of 932 acres and storage capacity of 9,134 million gallons. Drainage area of reservoir 14 square miles. Increase in 2050 safe yield - 6.4 million gallons per day Estirriated cost - $91 million Will require land acquisition Assumes minimum flowby - 30% of mean annual flow Approximately 77 acres of wetland impacts Impacts to threatened/endangered species undetermined; survey may be required Direct impacts to 4 previously identified historic structures (eligibility not determined); additional architectural surveys required Potential indirect impacts to 3 previously identified historic properties (eligibility not determined); additional surveys necessary Potential displacement of 6 residences 34 wi{~va~ 30502h0.p65 Construction of Dam and Reservoir on MeChums River Near Lake Albemarle Construction of a dam and reservoir on Mechums River 0.5 miles northeast of Batesville. Includes a new 20 mgd intake structure, 8 mgd expansion of the South Fork Rivanna Reservoir intake, raw water pump station, water treatment plant and finished water pump station. Normal pool elevation of reservoir 520 feet with surface area of 973 acres and storage capacity of 7,896 million gallons. Drainage area of reservoir 94 square miles. Increase in 2050 safe yield - 13.3 million gallons per day Estimated cost- $68 million Will require land acquisition Assumes minimum flowby = 30% of mean annual flow Approximately 107 acres of wetland impacts James Spiny Mussel previously identified in vicinity; will need to examine potential impacts Direct impacts to 1 archaeological, site and 8 historic structures previously identified (eligibil- ity not determined); additional cultural resource surveys required Potential indirect impacts to 10 previously identified historic properties (eligibility not determined) Potential displacement of 21 residences 35 willva", 30502ho.p65 Construction of Dam and Reservoir on Mechums River Near Midway Construction of dam and reservoir on Mechums River one mile upstream of the 1-64 crossing near Midway. Includes a new 8.4 mgd intal~e structure. Normal pool elevation of reservoir 580feet with surface area of 477 acres and storage capacity of 3,477 million gallons. Drainage area of reservoir 34 square miles. · Increase in 2050 safe yield - 5.6 million gallons per day · Estimated cost - $26 million · Will require land acquisition · Assumes minimum flowby = 30% of mean annual flow · Approximately 52 acres of wetland impacts · James Spiny Mussel previously identified in vicinity; will need to examine potential impacts · Possible direct impact to 1 National Register Property (Miller School); will require furture investigation · Direct impact to 1 previously identified historic structure (eligibility not determined); additional architectural survey required · Potential indirect impacts to 5 previously identified historic properties (eligibility not determined); additional survey required · Potential displacement of 6 residences 36 witlva',. 30502ho.p65 Construction of Dam and Buck Island Creek Reservoir on Construction of a dam and reservoir on Buck Island Creek 0.5 miles upstream of Route 53. Includes a new 22.5 mgd intake structure, raw water pump station, water treatment plant and finished water pump station. Normal pool elevation of reservoir 340feet with surface area 1, 707 acres and storage capacity of 13,950 million gallons. Drainage area of reservoir 38 square miles. · Increase in 2050 safe yield o 15 million gallons per day · Estimated cost - $118 million · Will require land acquisition · Assumes minimum flowby = 30% of mean annual flow · Approximately 103 acres of wetland impacts Impacts to threatened/endangered species not determined; additional surveys may be re- quired Direct impacts to 4 previously identified historic structures (eligibility not determined); additional cultural resource surveys required Potential indirect impacts to 2 previously identified historic properties (eligibility not deter- mined) · Potential displacement of 14 residences 37 willva\ 30502ho.p65 Construction of Dam and Reservoir on Moormans River Construction of a dam and reservoir on Moormans River just downstream of confluence with Doyles River. Includes a new 17. 4 mgd intake structure and 5. 4 mgd expansion of the South Fork Rivanna River intake, raw water pump station, water treatment plant and finished water pump station. Normal pool elevation of reservoir 680feet with surface area of 817 acres and storage capacity of 9,202 million gallons. Drainage area of reservoir 53 square miles. · Increase in 2050 safe yield - 11.6 million gallons per day ' · Estimated cost - $106 million · Will require land acquisition · Assumes minimum flowby = 30% of mean annual flow · Approximately 68 acres of wetland impacts · Impacts to threatened/endangered species not determined; additional surveys may be required · Direct impacts to 9 historic structures and 1 archaeological site previously identified (eligibility not determined); additional cultural resource surveys required · Potential indirect impacts to 5 previously identified historic properties (eligibility not deter- mined) · Potential displacement of 22 residences 38 wdlva\ 30502ho. D65 12. 13. 14. 15 Water conservation - Development and implementation of a long term water conservation program consisting of plumbing fixture ehangeout and public education/awareness programs. ,~ Demand = 1.8 mgd Drought management- Development and implementation of a drought management plan including mandatory water conservation, ban on outdoor water use, and an operating scenario for RWSA's existing water supply facilities during severe drought conditions. ,1, Demand = 3.4 mgd Leak detection and meter calibration - Evaluation of leak detection/meter calibration programs implemented by the Albemarle County Service Authority and the City of Charlottesville who distribute finished water to the end users. Growth management - Attempt to slow population growth in the Albemarle County portion of the Urban Service Area to reduce future water demand. $ Demand = 1.5 mgd Physical Additions to Existing Water Supply System: 16. Regional cooperation - Identifying opportunities for a regional approach to meeting future water supply needs; based on coordination to date, only one neighboring water provider is considering short term and long term solutions to meet their future water needs. 1` Demand = 1.5 mgd 17. Aquifer storage and recovery -~ Storage of treated water in a suitable aquifer when water supply exceeds demand, and subsequent recovery of water during drought conditions. ? Safe Yield = 0 mgd 18. Groundwater- Conventional withdrawal of groundwater via installation of approximately 15 wells and then piping water to existing water treatment plants. 1' Safe Yield --- 0.1 mgd 19. James River withdrawal - Withdrawal of water from the James River at Scottsville and pumping it through a new pipeline to the South Fork water treatment plant for treatment. 1' Safe Yield = 15 mgd 20. Rivanna River withdrawal - Withdrawal of water from the Rivanna River near the Glenmore Country Club and treating it in a new water treatment plant. 1' Safe Yield = 4.7 mgd 21 Mechums River withdrawal - Withdrawal of water from the Mechums River at the site of the abandoned pump station during conditions of high flow. Water would be pumped to the Ragged Mountain Reservoirs. Would require rehabilitation of the pump station and intake. 1` Safe Yield = 0.2 mgd 22. Mechums River withdrawal and conversion of Ragged Mountain to pumped storage reservoir- Combining previous option with the expansion of the existing Ragged Mountain Reservoir system. Would include raising dam at Lower Ragged Mountain Reservoir by 50' to increase storage volume. 1` Safe Yield = 10 mgd 23. Buck Mountain Creek Reservoir- Construct a dam and 670-acre reservoir on Buck Mountain Creek 1.5 miles upstream of confluence of Buck Mountain Creek and the S. Fork Rivanna River Reservoir. 1` Safe Yield = 14.4 mgd 24~ North Fork Rivanna River Reservoir - Construct a dam and 1,057-acre reservoir on the North Fork of the Rivanna River 2 miles west of the North Fork Filtration Plant. 1' Safe Yield = 15.4 mgd 25. Preddy Creek Reservoir - Construct a dam and 932-acre reservoir on Preddy Creek 2.5 miles northeast of the North Fork Rivanna water treatment plant. 1' Safe Yield = 6.4 mgd 26. Mechums River Reservoir near Lake Albemarle - Construct a dam and 973-acre reservoir on the Mechums River 0.5 miles northeast of Batesville. 1' Safe Yield= 13.3 mgd 27. Mechums River Reservoir near Midway - Construct a dam and 477-acre reservoir on the Mechums River 1 mile upstream of the 1-64 crossing near Midway. ? Safe Yield = 5.6 mgd 28. Buck Island Creek Reservoir- Construct a dam and 1,707-acre reservoir on Buck Island Creek 0.5 miles upstream of Route 53. 1` Safe Yield = 15 mgd 29. Moormans River Reservoir - Construct a dam and 817-acre reservoir on the Moormans River just downstream of its confluence with the Doyles River. 1' Safe Yield = 11.6 mgd More information on these alternatives can be found on the RWSA home page: http://monticello.avenue.gen.va.us/Gov/RWSA/ For more information on the Water Supply Study or to obtain copies of the reports referred to in this insert, please contact the RWSA at (804) 977-2970 ext. I01 WATER SUPPLY STUDY The Rivanna Water and Sewer Authority (RWSA) is responsible for providing potable water to the Albemarle County Service' Authority and the City of Charlottesville Public Works Department who then distribute the water to their respective customers. The following information is a synopsis of the ongoing water supply study being conducted on behalf of the RWSA by the firms of Vanasse Hangen Brustlin, Inc., O'Brien &Gere Engineers, Inc., and McSweeney Burtch and Crump. This information, still considered "draft", is being distributed to make each ~customer aware of the study efforts and to keep citizens in our community informed. PLANNING HORIZON: Year 2050 STUDY AREA: 'Urban Service Area" City of Charlottesville and portions of Albemarle County I. SUMMARY OF WATER SUPPLY AND WATER DEMAND ANALYSIS There are currently four sources of raw water for customers in the Urban Service Area: 1) South Fork Rivanna River Reservmr, 2) Sugar Hollow Reservoir, 3) Ragged Mountain Reservoirs, and 4) an intake at the North Fork of the Rivanna River. The "safe yield" of this system (the amount of water that can be safely withdrawn during a severe drought) is currently between 12 and 13 million gallons per day (mgd). In the fall of 1997, the study team published the results of their water supply and water demand analyses which included projections of available water supply and anticipated water demand within the Urban Service Area in the year 2050. Based on the results of the supply analysis, the safe yield of the existing water supply system is expected to decrease to approximately 4.5 mgd in 2050 primarily as a result of sedimentation in the South Fork Rivanna River Reservoir. Using four different approaches, the study team also p)ojected the amount of water to be used in the future by customers within the Urban Service Area. Based on the results of this analysis, water demand in the year 2050 is expected to be between 18 to 21 mgd. Combining the results of the water supply and the water demand analysis, a future water deficit of approximately 15 mgd is being used for the ongoing planning efforts. To meet future water needs, the study team developed the following range of alternatives which may be implemented either alone or in combination with each other. II. ALTERNATIVES UNDER CONSIDERATION Improvements to the Efficiency of' Existing Water Resources: Dredge South Fork Rivanna River Reservoir- Periodic dredging of accumulated sediments from the reservoir through 2050, each time returning it to its original capacity. ? Safe Yield = 10 mgd Decrease sedimentation into South Fork Rivanna River Reservoir- Implementation of watershed protection measures aimed at reducing the amount of sediment transported to the reservoir. ~' Safe Yield = To be determined Revise downstream release regime at South Fork Rivanna River Reservoir - Revision of current release regime at S. Fork Rivanna dam such that natural stream flow would not be augmented during severe drought conditions. ? Safe Yield = 3.8 mgd 4' crest controls on South Fork Rivanna dam - Addition of four-foot crest controls on existing dam to increase the normal pool elevation of the reservoir by four feet. ~' Safe Yield = 6 mgd 8' crest controls on South Fork Rivanna dam - Addition of eight-foot crest controls on existing dam to increase the normal pool elevation of the reservoir by eight feet. ~' Safe Yield = 11 mgd Use South Fork Rivanna River Reservoir as pUmped storage reservoir - Removal of water from the Rivanna River during high flow conditions and pumping it to the existing S. Fork Reservoir for storage. ~' Safe Yield = 0 mgd 5' drawdown of Chris Greene Lake - Convey water from Chris Greene Lake to the North Fork Rivanna River during severe drought conditions in order to supplement the existing N. Fork Rivanna River water system. Would be limited to a 5-foot drop of pool elevation in the lake. ~' Safe Yield = 3 mgd 20' drawdown of Chris Greene Lake - Maximum release of water from Chris Greene Lake to the North Fork Rivanna River during severe drought conditions. '1' Safe Yield = 5.5 mgd 11. Use Chris Greene Lake as pumped storage reservoir- Removal of water from the North Fork Rivanna River during high floTM conditions and pumping it to Chris Greene Lake for storage. ~' Safe Yield = 0 mgd Dredge Sugar Hollow Reservoir - A one-time dredging of Sugar Hollow Reservoir to remove debris deposited in the 1995 landslide and any accumulated sediment. ~' Safe Yield = 0.1 mgd Indirect reuse - Pumpback of treated effluent from the Moore's Creek waste water treatment plant to the Mechurns River via a new pipeline to then augment flow into the South Fork Rivanna River Reservoir. ~' Safe Yield = 15 mgd ALTERNATIVES UNDER CONSIDERATION I. NO ACTION II. REDUCE DEMAND A. Water conservation B, Drought management C. Leak detection and meter calibration D. Growth management III, INCREASE SUPPLY A. Improvements to the Efficiency of Existing Water Resources 1. South Fork Rivanna River Reservoir a. Dredge b. Decrease sedimentation c, Revise downstream release regime d. Add crest controls ii. 8' e. Use SFRR as pumped storage reservoir 2. Chris Green Lake a. 5' drawdown b. 20' drawdown 3. Sugar Hollow Reservoir: Dredge 4. Indirect reuse: pumpback of treated effluent to Mechums River and SFRR B. Physical Additions to the Existing Supply System 1. Regional cooperation 2. Aquifer storage and recovery 3. Groundwater withdrawal (wells) 4. Withdrawal of raw water from local rivers a. James River b. Rivanna River c. Mechums River i. direct withdrawal ii withdrawal with expansion of Ragged Mt. reservoir system 5. Construction of new reservoirs a. Buck Mountais Creek b. North Fork Rivanna River c. Preddy Creek d. Mechums River near Lake Albemarle e. Mechums River near Midway f. Moormans River