HomeMy WebLinkAboutWPO202000020 VSMP - SWPPP 2020-04-02 (2)A.
SEH
Building a Better World
for All of Us'
Engineers I Architects I Planners I Scientists
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Erosion Control Plan & Stormwater Management Plan
Albemarle - Berkeley Water Pump Station
Charlottesville Virginia
SEH No. RIVAN 154511
March 23, 2020
I hereby certify that this report was prepared by me or under my direct supervision, and
that I am a duly Licensed Professional Engineer under the laws of the State of Virginia.
Date: 3/12/2020 License No.: 0402051131
Reviewed By: Maria Tiegs Date: 3/12/2020
Short Elliott Hendrickson Inc.
3535 Vadnais Center Drive
St. Paul, MN 55110-3507
651.490.2000
SEH
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i
SEH
Building a Better World
for All of Us"
Contents
Certification Page
Contents
1 Project Overview........................................................1
2 Site Description..........................................................1
2.1 Drainage.................................................................................................1
2.2 Disturbance............................................................................................1
2.3 Soils........................................................................................................1
2.4 Adjacent Areas.......................................................................................2
2.5 Steep Slopes Overlay.............................................................................2
3 Erosion Control Plan..................................................3
3.1 Temporary Measures.............................................................................3
3.2 Stabilization............................................................................................3
3.3 Erosion Control Sequence......................................................................4
3.4 Maintenance and Sediment Disposal.....................................................5
4 Stormwater Management Plan...................................6
4.1 Water Quality Requirements (9VAC25-870-63. Water quality design
criteria requirements.).............................................................................6
4.2 Water Quantity Requirements (9VAC25-870-66. Water quantity.) .........6
List of Tables
Table1 — Land Cover.................................................................................................6
Table 2 — 2 & 10-year 24 hr Peak Flows....................................................................7
SEH is a registered trademark of Short Elliott Hendrickson Inc.
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Contents (continued)
List of Appendices
Drainage Area Maps
Water Quality Calculations
Water Quantity Calculations — Channel Protection
Water Quantity Calculations — Flood Protection
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Erosion Control Plan & Stormwater
Management Plan
Albemarle -Berkeley Water Pump Station
Prepared for Riv,�
2
2.1
2.2
2.3
inna Water and Sewer Authority
Project Overview
As part of on -going maintenance projects, the Rivanna Water and Sewer Authority (RWSA) is
proposing to demolish the abandoned sand filters and associated buried piping at the Albemarle
— Berkeley Wastewater Pump Station located on the Albemarle High School grounds. The sand
filter structures are primarily buried and have been out of service since the mid 1970's, when they
were replaced by several pump stations including the Albemarle -Berkeley Wastewater Pump
Station facilities. Through the middle 2000's, the filters were used as emergency storage until a
backup generator was installed. Two of the three sand filter beds are capped with concrete. The
pump station still conveys wastewater from this site into the RWSA interceptor system, to be
treated at their downstream wastewater treatment facilities. This work includes removal and
abandonment of previously abandoned sand filters, storage basins, chlorination facilities, splitter
box, yard waterline piping and associated piping and structures. The project will eliminate old, un-
used systems, and replace these areas with pervious, vegetated surfaces.
Site Description
Drainage
The side is located in the Ivy Creek watershed and slopes south to north. The site receives some
drainage from Lambs Lane and the parking lot to the south.
Disturbance
The proposed work will disturb approximately 0.48 acres.
Soils
The site is made up of one soil types. Soils have been identified and classed by the Natural
Resources Conservation Service (NRCS). For the stormwater evaluations, all soil were assumed
type D soils.
88-Culpeper Fine Sandy Loam
The Culpeper soils exist predominantly on interfluves and the typical depth to the water table is
over 80 inches. Culpeper soils originate from residuum weathered from meta-arkosic sandstone
and quartzite. Slopes range from 2 to 7 percent.
RIVAN 154511
Page 1
2.4 Adjacent Areas
The Albemarle — Berkeley Water Pump Station is located within an easement on land owned by
Albemarle School Board. Land use immediately surrounding the property on the leased section
of land consists of several school campuses and support buildings.
2.5 Steep Slopes Overlay
Critical steep slopes exist on the site. From Albemarle County Code, preserved slopes, by right:
18.4.2 The provisions in this section through section 4.2.5 implement the comprehensive plan by
protecting and conserving steep hillsides together with public drinking water supplies and flood
plain areas because of the increased potential for soil erosion, sedimentation, water pollution and
sewage disposal problems associated with the disturbance of critical slopes. The disturbance of
critical slopes may result in: rapid and/or large-scale movement of soil and rock; excessive
stormwater run-off; siltation of natural and man-made bodies of water; loss of aesthetic resource;
and in the event of onsite sewage system failure, a greater travel distance of septic effluent, all of
which constitute potential dangers to the public health, safety and/or welfare. The regulations in
sections 4.2.1, 4.2.2, 4.2.3 and 4.2.4 are intended to direct building and onsite sewage system
locations to terrain more suitable to development and to discourage development on critical
slopes, and to supplement other regulations regarding the protection of public water supplies and
encroachment of development into flood plains.
Based on the figure below, the critical slopes appear to be at the walls of the sand filters, and
therefore are manmade. These walls will be removed as part of the project, and the site graded
to remove the critical slope.
Figure 1 — Critical Slopes
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 2
3 ' Erosion Control Plan
The erosion and sediment control devices and measures have been designed and placed in
accordance with the Virginia Erosion and Sediment Control Handbook (VESCH), Third Edition,
1992.
3.1 i Temporary Measures
Temporary measures are used to limit erosion and contain sediment within areas denude of
vegetation.
3.1.1 Construction Entrance (CE)
A temporary stone construction entrance shall be used to prevent tracking of material from
construction vehicles off of the site. The construction entrance shall be constructed in
accordance with plate 3.02-1 of the VESCH and meet construction specifications of Std. & Spec.
3.02 of the VESCH. Maintenance of the construction entrance shall be in accordance with Std.
and Spec. 3.02 of the VESCH. See E&S plan sheet of the SWPPP for placement location.
3.1.2 I Silt Fence (SF)
Silt fence shall be use to prevent sediment from leaving the site. Silt fence shall be constructed
in accordance with plate 3.05-2 of the VESCH. Installation, construction specification, and
maintenance of the silt fence shall meet Std. & Spec. 3.05 of the VESCH. See E&S plan sheet of
the SWPPP for placement location.
3.1.3 Tree Preservation & Protection (TP)
Tree protection fence shall be used to protect existing groves of trees. The tree protection fence
shall be constructed and maintained in accordance with the Tree Protection Fence standard
detail on the E&S Detail plan sheet of the SWPPP. See the E&S plan sheet of the SWPPP for
placement location.
3.2 Stabilization
3.2.1 Temporary Stabilization
Temporary stabilization shall be obtained by temporary seeding (TS), mulching (MU), and Soil
Stabilization Blankets & Matting (B/M). Temporary seeding shall performed in accordance with
Std. & Spec. 3.31 of the VESCH, and temporary mulching shall be performed in accordance with
Std. & Spec. 3.35. Soil stabilization blankets & matting shall be in accordance with St. & Spec.
3.36 VESCH. Temporary seeding and mulching shall be used on any disturbed area that shall
not be worked for more than 14 days.
3.2.2 Permanent Stabilization
Permanent stabilization shall be obtained by permanent seeding (PS) and soil stabilization
blanket & matting (B/M). Permanent seeding shall be in accordance with Std. & Spec 3.32.
Treatment 1 soil stabilization blanket meeting Std. & Spec 3.36 shall be used over the permanent
seeding. Placement of the soil stabilization blanket shall be in accordance with standard plates
3.36-1 and 3.36-2.
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 3
3.2.3 Seeding
Seeding shall conform to the following:
Type
Minimum
Seed Purity
N
Minimum
Germination
N
Maximum
Weed Seed
N
Kentucky 31 Tall Fescue
97
85
0.50
Perennial Ryegrass
98
90
0.50
Kentucky Bluegrass
97
85
0.50
Annual Ryegrass
97
90
0.50
Weeping Lovegrass
98
87
0.50
German Millet
98
85
0.50
Cereal (Winter) Rye
98
85
0.50
Redtop
94
80
0.50
Seeding mixtures to be used on the projected as follows:
Permanent Seeding
180
Kentucky 31
5 Perennial 5 Kentucky
#/acre
Tall Fescue
#/acre Ryegrass #/acre Bluegrass
....................................................................................................................................................._........................._................................................_.....................
Temporary Winter
575
Annual
_..................................
75 Cereal
Seeding
#/acre
Ryegrass
#/acre (Winter) Rye
.........................................................................................._.
Temporary Spring
75
_. _.....................
Annual
_......................... ................................................. _......................... ...................................
Seeding
#/acre
Ryegrass
Temporary Summer
75
German
Seeding
#/acre
Millet
3.3 � Erosion Control Sequence
1. No demolition, construction or land disturbance activities may begin until all perimeter
erosion control measures have been installed as per Contract Drawings. Perimeter
control devices include, silt fence, temporary stone construction entrance and tree
protection fence. If clearing is required for installation of a particular measure, all other
measures shown shall be installed first; clearing of the land necessary may then proceed.
2. Once all measures have been installed, the site shall be cleared and grubbed as
necessary within the limits of disturbance as per the Contract Drawings. Efforts shall be
made to minimize the amount of cleared area exposed at any given time.
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 4
3. Once clearing and grubbing is complete, any necessary topsoil stripping may begin.
Topsoil shall be stockpiled on site in the stockpile areas per the Contract Drawings. The
stockpile shall receive such temporary seeding measures as may be required. Any soil
take offsite shall be stockpiled at locations with all required permits. If offsite location
does not have all required permits, the contractor is responsible for obtaining all required
permits.
4. Demolition, earthwork and construction operations may begin once topsoil has been
removed and stockpiled.
5. Once perimeter erosion control measures are in place, construction activities for the
project may begin.
6. All pipes shall be installed in accordance with standard construction techniques. Only the
length of trench in which pipe can be installed in one day's time shall be open at any
time, with spoil material placed on the uphill side of the trench. Piping shall be capped at
the end of each day's work to prevent sediment from entering. The trench shall be
backfilled at the end of each day's work and the disturbed area seeded and mulched
within seven (7) days of backfill.
7. All inlets shall have inlet protection installed immediately after installation.
8. Temporary soil stabilization shall be applied within seven (7) days to denude areas that
may not be at final grade but will remain dormant for longer than fourteen (14) days,
except for that portion of the site on which work will be continuous beyond fourteen (14)
days.
9. Upon completion of final grading, permanent seeding, mulching and fertilization
measures shall be employed on all disturbed areas. Permanent soil stabilization shall be
applied within seven (7) days after final grade is reached on any portion of the site. All
remaining erosion control measures shall remain in place until the entire site has been
stabilized.
10. Once permanent stabilization has occurred, temporary sediment control measures shall
be removed. Any areas disturbed by the removal of these measures shall be returned as
closely as possible to original condition and seeded, mulched and fertilize
3.4 Maintenance and Sediment Disposal
All sediment and erosion control measures shall be inspected upon installation, at least once
every four business days or at least once every five business days and no later than 24 hours
following a measureable storm event. Repairs to, or replacement of, measures shall occur
immediately if necessary and accumulated sediment removed as needed.
Sediment shall be removed from all erosion control measures when the sediment storage volume
of the measure has become 50% full. All removed sediment shall be disposed of in an approved
manner at the stockpile location or a location to be designated by the Engineer or Owner. Steps
shall be taken at the disposal site to insure that further sediment transport does not occur.
Permanent or temporary soil stabilization shall be applied to denuded areas within seven days
after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied
within seven days to denuded areas that may not be at final grade but will remain dormant for
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 5
longer than 14 days. Permanent stabilization shall be applied to areas that are to be left dormant
for more than one year
4 Stormwater Management Plan
This stormwater management plan (SMP) has been prepared in accordance with the Virginia
Code of Ordnances. The SMP addresses water quality and water quantity requirements to the
demolish the abandoned sand filters and associated buried piping at the Albemarle - Berkeley
Wastewater Pump Station located on the Albemarle High School grounds. Drainage area maps
are located in Appendix A.
4.1 Water Quality Requirements (9VAC25-870-63. Water quality
design criteria requirements.)
Virginia Runoff Reduction Method Spreadsheet (VRRMS) version 3 was utilized to meet water
quality requirements outlined in section 9VAC25-870-63 of Virginia Code.
4.1.1 Pre -Post Redevelopment Land Cover
Appendix A3 and A4 show the pre and post redevelopment land cover. Table 1 below
summarizes the land cover for both conditions.
Table 1 - Land Cover
..
Preconditions 0.33 0.15 0.48
(acres)
Post
conditions 0.48 0 0.48
(acres)
4.1.2 I Calculations
Based on the VRRMS, no TP reductions are required. The VRRMS summary page is provided in
Appendix B.
4.1.3 TP Reduction Achieved
The proposed demolition results in no TP reduction required. Therefore, no permanent
stormwater BMP's are proposed.
4.2 Water Quantity Requirements (9VAC25-870-66. Water quantity.)
The area disturbed all drains to the north east. The Table 1 above summarizes pre and post
surface conditions
4.2.1 ' Channel Protection
The methodology outlined in 9VAC25-870-66.B.3.a was used to meet channel protection
requirements.
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 6
Q_Developed<_I.F.*(Q_Predeveloped*QRV�_Predeveloped )/QRVI_Developed
The Runoff Volume for pre and post development were calculated using the SCS TR-55 method.
The Peak Runoff was calculated using the graphical peak discharge method.
The full calculations are provided in Appendix C. A summary of the 9VAC25-870-66.3.a
evaluation is shown below. The QDeveloped, 0.2 cfs, is less than the maximum allowable runoff, 0.4
cfs, from the site.
I.F. (site > 1 acre):
QDeveloped:
RVDeveloped:
cfs 0.2
cf 500
QPre-Developed cfs 20.3
RVPre-Developed cf 800
1 • F. * (QPre-Developed* RVPre-Developed)/RVDeveloped 0.4
4.2.2 Flood Projection
The pre and post peak runoff for the drainage area was calculated using the rational method.
The post development peak flow from a 2 & 10-year 24 hour storm event is shown to be less than
the pre development peak flow from the same storm event. Thus meeting sub paragraph C.2.b
of 9VAC25-870-66. The tables below summarize the peak flows and the full calculations can be
found in Appendix D.
Table ^ " � 10•year 24 hr Peak Flows
EROSION CONTROL PLAN & STORMWATER MANAGEMENT PLAN RIVAN 154511
Page 7
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Appendix A
Drainage Area Maps
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General Vicinity Map
Albemarle — Berkeley Water Pump Station
Albemarle — Berkeley
Water Pump Station
C h a - I .," T I � Y. H LI n'i p h I is Palk.
F':.-,i k
IZ fJ
ottesville
H I d
Source: Albemarle County GIS (not to scale)
Pantop-,
j
M1 I -is
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USDA United States
Department of
Agriculture
MRCS
Natural
Resources
Conservation
Service
F
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
200 ft
Custom Soil Resource
Report for
Albemarle
County, Virginia
P I C
i0
If
February 27, 2020
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/
portal/nres/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil
Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/?
cid=nres142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................
2
SoilMap..................................................................................................................
5
SoilMap................................................................................................................6
Legend..................................................................................................................7
MapUnit Legend..................................................................................................
8
MapUnit Descriptions..........................................................................................
8
Albemarle County, Virginia..............................................................................10
21 B—Culpeper fine sandy loam, 2 to 7 percent slopes ..............................
10
21 C—Culpeper fine sandy loam, 7 to 15 percent slopes ............................
11
94C—Toast sandy loam, 7 to 15 percent slopes.........................................12
References............................................................................................................13
Glossary................................................................................................................15
4
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
5
Custom Soil Resource Report
0
719050 719080 719110
380 4' 42" N
e
a
8
d 4
o }
a
0
v
Soil Map
N
719140 719170 719200 719230 719260 719290 719320
38° 4' 42" N
%
v
i
sr '�
•1
1
,o
J
rf
N
V
w �
' ; • o
38° 4' 36" N - 71— 38° 4' 36" N
719050 719080 719110 719140 719170 719200 719230 719260 719M 719320
3 �
Map Scale: 1:1,310 if printed on A landscape (11" x 8.5") sheet.
N Meters
0 15 30 60 90
Feet
0 50 100 200 300
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
6
MAP LEGEND
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
. 0
Soil Map Unit Lines
0
Soil Map Unit Points
Special
Point Features
(
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
--
Mine or Quarry
Miscellaneous Water
0
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
_
Severely Eroded Spot
Sinkhole
Slide or Slip
oa
Sodic Spot
Custom Soil Resource Report
MAP INFORMATION
t�j
Spoil Area
The soil surveys that comprise your AOI were mapped at
1:15,800.
Stony Spot
Very Stony Spot
Warning: Soil Map may not be valid at this scale.
Wet Spot
Enlargement of maps beyond the scale of mapping can cause
Other
misunderstanding of the detail of mapping and accuracy of soil
«-
Special Line Features
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
Water Features
scale.
Streams and Canals
Transportation
Please rely on the bar scale on each map sheet for map
+44
Rails
measurements.
Interstate Highways
Source of Map: Natural Resources Conservation Service
US Routes
Web Soil Survey LIRL:
Coordinate System: Web Mercator (EPSG:3857)
Major Roads
Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
Background
distance and area. A projection that preserves area, such as the
Aerial Photography
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Albemarle County, Virginia
Survey Area Data: Version 13, Sep 17, 2019
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: May 20, 2019—Aug
1. 2019
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
7
Custom Soil Resource Report
Map Unit Legend
Map Unit Symbol
Map Unit Name
Acres in AOI
Percent of AOI
21 B
21C
Culpeper fine sandy loam, 2 to
7 percent slopes
3.6
46.8%
Culpeper fine sandy loam, 7 to
15 percent slopes
1.7
21.8%
94C
Toast sandy loam, 7 to 15
percent slopes
2.4
31.5%
Totals for Area of Interest
7.8
100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
0
Custom Soil Resource Report
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha -Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
0
Custom Soil Resource Report
Albemarle County, Virginia
21 B—Culpeper fine sandy loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: kb8k
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Culpeper and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Culpeper
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from meta-arkosic sandstone and quartzite
Typical profile
H1 - 0 to 8 inches: fine sandy loam
H2 - 8 to 30 inches: clay
H3 - 30 to 37 inches: sandy clay loam
H4 - 37 to 45 inches: fine sandy loam
H5 - 45 to 50 inches: bedrock
H6 - 50 to 79 inches: bedrock
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: 40 to 79 inches to lithic bedrock; 40 to 79 inches to
paralithic bedrock
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 6.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
10
Custom Soil Resource Report
21 C—Culpeper fine sandy loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: kb8l
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Culpeper and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Culpeper
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from meta-arkosic sandstone and quartzite
Typical profile
H1 - 0 to 8 inches: fine sandy loam
H2 - 8 to 30 inches: clay
H3 - 30 to 37 inches: sandy clay loam
H4 - 37 to 45 inches: fine sandy loam
H5 - 45 to 50 inches: bedrock
H6 - 50 to 79 inches: bedrock
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: 40 to 79 inches to paralithic bedrock; 40 to 79 inches
to lithic bedrock
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 6.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
11
Custom Soil Resource Report
94C—Toast sandy loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: 2v7k9
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Toast and similar soils: 90 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Toast
Setting
Landform: Interfluves
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 7 inches: sandy loam
BA - 7 to 11 inches: sandy clay loam
Bt - 11 to 30 inches: clay
C - 30 to 60 inches: sandy clay loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 8.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
12
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/
nres/detail/national/soils/?cid=nres142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nresl42p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nresl42p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/
home/?cid=nres142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
13
Custom Soil Resource Report
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/
nres/detail/soils/scientists/?cid=nres142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/?
cid=nres142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nres.usda.gov/Internet/FSE_DOCUMENTS/nresl42p2_052290.pdf
14
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it
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7
7
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N
N
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Q_
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LEGEND
-- LIMITS OF DISTURBANCE I
I � I
TF XTEMPORARY SECURITY FENCE
� l /
GENERAL NOTES:
1 � /
1. TOPOGRAPHY DATA IS DERIVED FROM 4-FOOT INTERVAL COUNTY GIS DATA. // 4•//
ASSUMED CONTOURS ARE APPROXIMATE.
2. DISPOSE OF ALL DEMOLISHED MATERIALS IN APPROVED OFF -SITE LOCATION.
3. CONTRACTOR IS REQUIRED TO KEEP ACCESS TO ALL ALBEMARLE COUNTY SCHOOL
FACILITIES AND PUMP STATION DURING CONSTRUCTION.
DRAWN BY: TJS
DESIGNER: MAIM
CHECKED BY: XXX
DESIGN TEAM
0= =
11
1
I
I I
REVISIONS
Appendix A4 - Post Land Cover
I dry
557_SAND FILTER #3
s
/ Mangaged Turf /
\ma/
SAND FILTER #2
\ NIL \
t3�
1 , of
SAND FILTER #1
f� 1 Disturbance (TYP)
I
/ ED
11 1 \ \
Mangaged Turf _
\ \ \ 0
10000
1000,
_
PHONE:262.646.6855
501 MAPLE AVENUE
SEH
DELAFIELD, WI 53018
DE
www.sehinc.com
\ I i
RIVANNA WATER AND
SEWER AUTHORITY
ALBEMARLE COUNTY, VA
S�9
0
ss �
- 20 0 20 40
scale 10 feet
Managed Turf
—_I I
I �
!mow
L
PARCEL ID: 06000-00-00-078AO
TAX MAP: 60-78A
COUNTY OF ALBEMARLE
SCHOOLBOARD
DB: 287/414
ZONING: RURAL AREAS
GRADING PLAN
ALBEMARLE-BERKELEY PUMP STATION
STORAGE BASIN DEMOLITION
FILE NO.
154511
1w,
C3.0
DATE 03/06/2020 I OF 7
U
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ry
(D
O
7-
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0
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co
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Q_
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N
n
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0
N
0
N
M
ai
M
U)
LEGEND
-- LIMITS OF DISTURBANCE I
I � I
TF XTEMPORARY SECURITY FENCE 1 1
� l /
1 /
GENERAL NOTES:
1. TOPOGRAPHY DATA IS DERIVED FROM 4-FOOT INTERVAL COUNTY GIS DATA. // 4•//
ASSUMED CONTOURS ARE APPROXIMATE.
2. DISPOSE OF ALL DEMOLISHED MATERIALS IN APPROVED OFF -SITE LOCATION.
3. CONTRACTOR IS REQUIRED TO KEEP ACCESS TO ALL ALBEMARLE COUNTY SCHOOL
FACILITIES AND PUMP STATION DURING CONSTRUCTION.
DRAWN BY: TJS
DESIGNER: MAIM
CHECKED BY: XXX
DESIGN TEAM
0= =
11
I
I
I I
REVISIONS
Appendix A3 - Pre Land Cover
/
I '
I 1 I l l r dry
557_SAND FILTER #3
UF
Mangaged Turf
0000
� I
r� I
fn 1 Impervious (TYP) Disturbance (TYP)
I
11 1 \ \
Mangaged Turf _
\ \ \ \ 0!
/
.00�
0000,
r ' /
\ \\ \\�\,� \\\\\ r` /
_
PHONE:262.646.6855
501 MAPLE AVENUE
SEH
DELAFIELD, WI 53018
DE
www.sehinc.com
\ I i
RIVANNA WATER AND
SEWER AUTHORITY
ALBEMARLE COUNTY, VA
MEN,
IMMMI
L
20 0 20 40
scale -1*Ow feet
PARCEL ID: 06000-00-00-078A0
TAX MAP: 60-78A
COUNTY OF ALBEMARLE
SCHOOLBOARD
DB: 287/414
ZONING: RURAL AREAS
GRADING PLAN
ALBEMARLE-BERKELEY PUMP STATION
STORAGE BASIN DEMOLITION
FILE NO.
154511
1w,
C3.0
DATE 03/06/2020 I OF 7
Appendix B
Water Quality Calculations
this page intentionally left blank
Virginia Runoff Reduction Method Worksheet
DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0
BMP Design Specifications List: 2013 Draft Stds & Specs
Site Summary
Project Title: ABW PS - Demo
Date: 3.12.2020 Total Rainfall (in): 43
Total Disturbed Acreage: 0.48
Site Land Cover Summary
Pre-ReDevelopment Land Cover (acres)
®
A soils
B Soils
C Soils
D Soils
Totals
% of Total
Forest/Open (acres)
0.00
0.00
0.00
0.00
0.00
0
Managed Turf (acres)
0.00
0.00
0.00
0.33
0.33
69
Impervious Cover (acres)
0.00
0.00
0.00
0.15
0.15
31
0.48
100
Post-ReDevelopment Land Cover (acres)
A soils
B Soils
C Soils
D Soils
Totals
% of Total
Forest/Open (acres)
0.00
0.00
0.00
0.00
0.00
0
Managed Turf (acres)
0.00
0.00
0.00
0.48
0.48
100
Impervious Cover (acres)
0.00
0.00
0.00
0.00
0.00
0
0.48
100
Site Tv and Land Cover Nutrient Loads
® Final Post -Development
,�
(Post-ReDevelopment
Impervious)
& New Im p
Post-
ReDevelopment
Post-
Development
(New Impervious)
Adjusted Pre-
ReDevelopment
Site Rv 0.25
0.25
0.47
Treatment Volume (ft) 436
436
817
TP Load (lb/yr) 0.27
0.27
0.51
Total TP Load Reduction Required (lb/yr) -0.19 -0.19 0
® ® Final Post -Development Load
®® ®®
Pre-
(Post-ReDevelopment & New Impervious)
ReDevelopment
TN Load (Ib/yr) 1.96
3.67
Pre -
Final Post -Development
Post-ReDevelopment TP
ReDevelopment
TP Load per acre
Load per acre
TP Load per acre
(Ib/acre/yr)
(Ib/acre/yr)
Ib acre/ r
1.07
0.57
0.57
Summary Print
Virginia Runoff Reduction Method Worksheet
Site Compliance Summary
Maximum Y Reduction Required Below 10%
Pre-ReDevelopment Load
Total Runoff Volume Reduction (ft3)
0
Total TP Load Reduction Achieved (lb/yr)
0.00
Total TN Load Reduction Achieved (lb/yr)
0.00
Remaining Post Development TP Load
0.27
(lb/yr)
Remaining TP Load Reduction (lb/yr)
Required
0.00
"TARGET TP REDUCTION EXCEEDED BY 0.19 LB/YEAR **
Summary Print
Virginia Runoff Reduction Method Worksheet
Drainage Area Summary
Drainage Area Compliance Surnmar
Summary Print
Virginia Runoff Reduction Method Worksheet
Runoff Volume and CN Calculations
• �� •c asas^rO's�`,..:^»eaaease«:.>;3�Oic'saxaoa• 1- ear storm 2-year storm 10- ear storm
Target Rainfall Event (in) 1.44 3.68 5.57
Drainage Areas
RV & CN
Drainage Area A
Drainage Area B
Drainage Area C
Drainage Area D
Drainage Area E
CN
'
'ss'as'c .a;e:ees'a>
0
0
0
0
0
RR (ft)
®
0
0
0
0
0
1-year return period
RV wo RR (ws-in)
0.00
0.00
0.00
0.00
0.00
RV w RR (ws-in)
0.00
0.00
0.00
0.00
0.00
CN adjusted
0
0
0
0
0
2-year return period
RV wo RR (ws-in)
0.00
0.00
0.00
0.00
0.00
RV w RR (ws-in)
0.00
0.00
0.00
0.00
0.00
CN adjusted
0
0
0
0
0
10-year return period
RV wo RR (ws-in)
0.00
0.00
0.00
0.00
0.00
RV w RR (ws-in)
0.00
0.00
0.00
0.00
0.00
CN adjusted
0
0
0
0
0
Summary Print
Appendix C
Water Quantity Calculations — Channel Protection
this page intentionally left blank
Prepared By
Date of Calculations
Client
Project Name
Description
Reviewer
Date Reviewed
Table 1: Drainage Area Calculations
Maria Tiegs
2/27/2020
RSWA
Albemarle - Berkeley Water Pump Station
Channel Analysis
CN Predevelopment Post development
[ac] [ac]
Impervious
98
0.15
0.00
Grassed
80
0.33
0.48
Wooded
77
0.00
0.00
Total 0.48 0.48
Table 2: Pre and Post Volume
-A.
SEH
BulldIng a Batter World
for All of Us"
units
Predeveloped
Developed
1-yr (24hr) precipitation (P)
in
1.44
1.44
Composite CNa
86
80
Storage Capacity (S)
in
1.63
2.5
Initial abstraction (la)
in
0.33
0.50
Runoff Depth (Q)
in
0.45
0.26
Drainage Area
sf
21,000
21,000
RV (Runoff Volume)
cf
800
500
a Composite CN value for "post development with treatment" obtained from Virginia RRM Spreadsheet,
Runoff Volume and CN tab
Table 3: Peak Flow (1yr-24hr)
units Predeveloped Developed Developed (with
Treatment)
1-yr (24hr) Peak Flow (Qp)b cfs 0.3 0.2
b Peak Flow values obtained from SCS Graphical Peak Discharge Spreadsheet
Channel Analysis 1 of 4
Table 4: Qdeveloped < 1.F.*Are-Developed* RUPre-Developed)/RV Developed)
I.F. (site > 1 acre):
0.9
QDeveloped•
0.2
RVDeveloped:
500
QPre-Developed•
0.3
RUPre-Developed •
800
1. F. * (QPre-Developed* RUPre-Developed)/RVDeveloped
0.4
Q _ (P — la )2
(P—Ij+S
la = 0.2S
S_1+00_10
CN
Q = runoff (in)
P = rainfall (in)
S = potential maximum retention after runoff
begins (in) and
la = initial abstraction (in)
Channel Analysis 2 of 4
-A.
Prepared By Maria Tiegs SEH
Date of Calculations
2/27/2020
Building a Beffer World
for All of_ Us*
Client
RSWA
Project Name
Albemarle -
Berkeley Water Pump
Station
Description
Channel Analysis
- SCS Graphical
Peak Discharge
Reviewer
Date Reviewed
Table 1: Drainage Area Calculations
Predevelopment
Post development
CN
[ac]
[ac]
Impervious
98
0.15
0.00
Grassed
80
0.33
0.48
Wooded
77
0.00
0.00
Total
0.48
0.48
Table 2: Runoff Depth Tc [hr]: 0.08
units Predeveloped Developed
1-yr (24hr) precipitation (P) in 1.44 1.44
Composite CNa 86 80
Storage Capacity (S) in 1.63 2.5
Initial Abstraction (la) in 0.33 0.50
Runoff Depth (Q) in 0.45 0.26
a Composite CN value for "post development with treatment" obtained from Virginia RRM Spreadsheet, Runoff
Volume and CN tab
Table 3: Unit Peak Discharge
units Predeveloped Developed
Initial Abstraction Oa in 0.33 0.50
UP 0.23 0.35
Unit Peak Discharge (q,,)` csm/in 968 949
b Values interpolated from Table 4-1
`Values obtained from Exhibit 4-II. Unit Peak Discharge for NRCS (SCS) type II rainfall distribution
SCS Graphical Peak Discharge 3 of 4
Table 4: Peak Discharge
units Predeveloped Developed Developed (with
Treatment)
Drainage area (Ar,) mi2 0.0008 0.0008 0.0008
Pond and Swamp adjustment factor (Fp) 1.0 1.0 1.0
Peak Discharge (qp) cfs 0.3 0.2 0
qp = �-u n-iQV
qp = peak discharge cfs
u = unit peak discharge c m/in
,, = drainage area, ()
= runoff in
p= pond and swamp adjustment factor
Exhibit 4-II Unit peal discharge (q) for NRCS (SCS) type II rainfall distribution
I
s
6
c
E
or
m
M
U
u
N
Y
R
a
7
Time of concentration (T.), (hours)
SCS Graphical Peak Discharge 4 of 4
Appendix D
Water Quantity Calculations — Flood Protection
this page intentionally left blank
Prepared By Maria Tiegs
Date of Calculations 3/12/2020
Client RSWA
Project Name Albemarle - Berkeley Water Pump Station
Description 2 yr & 10 yr Runoff Calculations
Reviewer
Date Reviewed
Table 1: Drainage Area Calculations
A
SEH
Building a Better World
for All of UO
a
Predevelopment
Post development
C
[ac]
[ac]
Impervious
0.90
0.15
0.00
Grassed - Steep slopes
0.28
0.33
0.48
Wooded
0.21
Total
0.48
0.48
a: Table 4-5 of the VSWMH, 1999 edition.
D soil conditions with greater than 6% slope.
Table 2: Rational Method Calculations
Tc [min]:
5.0
Units
Predevelopment
Post development
Composite C
0.47
0.28
2-yr Intensity (1)
in/hr
5.04
5.04
10-yr Intensity (1)
in/hr
6.64
6.64
2-yr Peak Flow (Q)
cfs
1.14
0.68
10-yr Peak Flow (Q)
cfs
1.50
0.89
Change in Q at 10 yr event
Where: Q = discharge (cfs)
C = runoff coefficient representing a ratio of runoff to rainfall
I = rainfall intensity (inl'hr)
A = drainage area (acres)
2 yr 10 yr Runoff Calculations 1 of 1
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