HomeMy WebLinkAboutWPO200900061 Review Comments Mitigation Plan 2010-11-23� OF AL
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project: North Pointe Stream Crossing [WPO- 2009 - 00061]
Plan preparer: Luke Dupont; TEC Inc. and Field Works
Owner or rep.: Neighborhood Investments, NP, LLC
Developer: Charles Rotgin; North Pointe Charlottesville, LLC c/o Great Eastern Management
Company
Plan received date: (Rev. 1) 25 October 2010
7 December 2009
Date of comments: (Rev. 1) 23 November 2010
14 January 2010
Reviewer: Phil Custer
The first resubmittal of the Mitigation Plan for the North Pointe Stream Crossing project, submitted on 25
October 2010, has been reviewed. The following comments must be addressed before approval of the set
is given:
1. The current plan does not appear to consider all proposed impacts to the buffer according to the
latest ESC plan. Since the December 7th submittal, a sediment trap and new channel have been
added within the buffer and must be accounted for. Also, please consider the encroachment of the
turn lane into the stream buffer in your calculation of buffer impacts. Use the limits of
disturbance from both ESC plans prepared by WW Associates to determine the total buffer
impacts for this portion of the North Pointe project.
(Rev. 1) Figure 5 does not match Figure 6 with regard to the stream buffer disturbance around
the culvert crossing. Figure 6 is correct. Also, the existing crossing should be excluded from
the disturbed buffer calculations. The "South" disturbance area does not need to be mitigated
because stormwater conveyance channels are permitted in the buffer with county approval per
17- 318.B.5 and 17- 318.0.6. Should "50,215sf ' in Section 1.2 be "88,165sf '? This number
would have to be updated based on issues raised earlier in this comment.
2. The side slopes of the stream crossing cannot be counted towards the total mitigation area. [17-
320-D.5] Also, the ESC plan for this stream crossing has a proposed groundcover proposed for
the side slopes to meet county requirements. The engineering division of the Community
Development Department is concerned a proposed forested condition on the 2:1 slopes would
experience more erosion than a woody groundcover.
(Rev. 1) This area of the site has been removed from the proposed plan.
3. An Army Corps of Engineers permit will be required prior to construction for the stream
restoration plans. If the applicant feels they do not need a permit for the proposed work, please
provide confirmation from an Army Corps of Engineer representative after submitting this package
to them.
(Rev. 1) When it is received, please forward Army Corps approval of the streambank work as
described on page 31 of the report.
4. Please provide a table summarizing proposed buffer impacts and proposed mitigation areas
(including the stream restoration equivalency outlined in the design manual). Considering the
Albemarle County Community Development
Engineering Review Comments
Page 2 of 2
increased impacts as identified in comment 1 and the prohibition of using the road side slopes as
called out in comment 2, it is our estimation that the total opportunities on site for mitigation will
not be enough to meet the requirements. Engineering review will allow the plan to be approved
short of the required 2:1 ratio if it appears that the applicant is providing mitigation in all other
practicable areas. (However, if a County Mitigation bank is established before plan approval, the
applicant will be required to pay into this bank for the mitigation that could not be provided on
site.) Additional areas of possible mitigation include streamwork at the confluence of Flat Branch
and the unnamed tributary north of the crossing (and other possible eroded banks north of the
culvert), the removal of the pond embankment, and VDOT outlet stabilization along Flat Branch.
(Rev. 1) On page 30 of the Mitigation Narrative, the design manual states that "1' of restored
channel for every 100sf of disturbed area" is a mitigation option. This implies that every Ift
linear feet of channel restoration is equivalent to 200sf of required planting area.
If the 12,000sf "North" section is not approved as part of the permanent stormwater
management facility, it must be replanted. This replanted area can be counted towards total
mitigation requirements.
The county currently does not have a mitigation bank set up and cannot accept any payment
for buffer disturbance. It appears as though the applicant has not exhausted all opportunities
along Flat Branch. As noted in the County's Stream Assessment performed in 2003 and shown
on page 29 of the narrative, there are erosion downstream of the roadway culvert. I expect
there are ample opportunities from road culvert to the river. The county assessment notes bank
erosion and buffer issues.
The cross - sections on pages 33, 34, and 35 are not clear in Figure 23 and it is very difficult to
decipher where along the stream which cuts are proposed. Two of these sections do not show
any construction (Streambank 2 and Streambank 3. If these designations correspond to Figure
23 then it appears that only 295ft of bank stream restoration is actually occurring.
5. Areas C and D appear to be isolated by steep slopes. Please detail how the areas are to be accessed
in order to be bushhogged. If grading or clearing of forest or trees is necessary, the work will need
to be included in the stream crossing ESC plan.
(Rev. 1) Comment has not been addressed.
6. Please show the ESC measures, limits of disturbance, and replanting plan for the construction
necessary to perform the stream channel restoration. For instance, how will the work within the
existing forest be performed without damaging trees that must remain? I suspect there will need to
be a temporary access road provided through the forest adjacent to the stream to haul away excess
sediment. How will this road be cleared, protected from erosion, and replanted?
(Rev. 1) Comment has not been addressed. Will the ESC plan be updated to include the
mitigation work?
7. The bond for the mitigation plantings will be computed at the time of plan approval.
(Rev. 1) Comment remains unchanged.
E2_mp_PBC_North Pointe Stream Crossing_wpo200900061.doc