HomeMy WebLinkAboutSDP201000091 Review Comments Minor Amendment 2011-01-17ALg�,��
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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: Treesdale Park; WPO- 2010 - 00078; SDP - 2010 -00091
Plan preparer: Mr. Scott Collins, PE; Collins Engineering
Owner or rep.: Albemarle Housing Improvement Program, Inc.
Date received: 3 December 2010
Date of Comment: 17 January 2011
Engineer: Phil Custer
The first submittal of the amendment to the site, ESC, and SWM plans for the Treesdale Park Project
(original site plan: SDP - 2010 - 00013; original WPO plan: WPO- 2010 - 00011) has been reviewed. The
following comments are provided.
A. SDP - 2010 -00091 General Comments
1. Please mimic the sheet numbering system of the previously approved plans so it's clear what
sheets are being modified and which are remaining the same.
2. Please provide the county with the Army Corps of Engineers permit for the temporary disturbance
needed to install the storm line across the intermittent stream.
3. If no changes are proposed on sheet 8, then please remove it from the set. If there are
modifications shown on this sheet, please identify them.
4. Similarly, if no changes are proposed on sheet 13, then please remove it from the set.
B. SDP - 2010 -00091 Minor Site Plan Amendment Comments
1. References and callouts to the previous stormsewer alignment are still shown on the plan. Please
revise these notes and remove the proposed riprap from the channel that was to be placed above
the pipe disturbance.
2. Please provide a safety slab on structure 4D.
3. Anchor blocks are needed on pipe 4C. Please use the same note that was provided for pipe from
structure S24.
4. The drainage system south of building 2 cannot drain to structure 34 without lowering the invert of
the VDOT structure significantly. This would require VDOT approval. The pipe from the
roofdrain collection system to structure 34 is further complicated by the foundation of the wall.
Please provide a detail of how this pipe is to pass through the wall. It may be difficult to get all of
the roofdrains of building 1 to structure 32 as well. What are the inverts of some of the
southwestern cleanouts?
5. In the area of the new wall, please refer to the wall rail detail on sheet S -5 of the original site plan.
C. WPO- 2010 -00078 Stormwater Management Plan Comments (Amendment to WPO- 2010 - 00011)
1. The county is under the impression from statements made by both applicants' representatives over
the last several years and the agreement recorded on DB 3775 PG645 that both Stonewater and
Treesdale are committed to a jointly used facility at the location of the recorded swm easements.
This SWM plan amendment appears to disrupt this commitment. The County Attorney's office
will need to review the applicable agreements and determine if and how Community Development
can approve such an amendment.
The plan is also confusing on many levels. To name a few points of confusion:
• The only modifications to the stormwater sheets appear to be the addition of new contours
into the previously approved proposed contours of the enhanced, extended - detention
facility and the addition of an underdrain system.
• All of the enhanced, extended detention facility details (including the Landscape
Schedule) of the previously approved plan are still on sheet 12 even though it is clear that
a biofilter is being shown over 90% of the facility.
• The wetland planting plan is still shown on the plan view detail on sheet 12.
• According to the plan view detail on sheet 12, the stormwater facility will no longer treat
runoff from majority of the Stonewater development. Such a reduction would require a
drastic alteration to the existing ESC plan.
• The modified simple spreadsheet has not been updated based upon the proposed bypass of
the majority of the Stonewater drainage area.
• The routing and downstream channel calculations have not been updated after the
reduction to the volume of the facility.
The problems above are not the only point of confusions on the project. I recommend the
applicants meet with staff to discuss the reasons for this submittal and potential solutions.
2. If a biofilter is still being proposed, a revised landscape plan is required. The plan must show 1
planting for each 100sf of biofilter bed area. The landscape plan must possess a shrub -to -tree ratio
between a 2:1 to 3:1. There must also be 3 species each of tree and shrub.
3. If a biofilter is still being proposed, a revised section of the biofilter meeting all state and county
requirements is required.
4. If a biofilter is still being proposed, the overflow from the biofilter must be a rigid surface like a
concrete weir, wall, or other drainage structure. A grass or riprapped overflow is too variable and
susceptible to erosion.
5. Since this plan is proposing to replace the existing stormwater management plan (WPO -2010-
00011), new stormwater facility management maintenance agreements will be needed. An
agreement on TMP 61 -184 will currently be required because the embankment of the stormwater
facility will be provided on that property.
6. If any variation of a SWM amendment is approved, another bond computation may be necessary.
D. WPO- 2010 -00078 Erosion and Sediment Control Plan Comments (Amendment to WPO -2010-
00011)
1. Please modify the limits of disturbance so that all proposed work within the lines.
2. If the revised ditch grading west of the offsite sanitary sewer work appeared on the previous ESC
plan, please include the grading on this amendment (currently 14).
3. The revision to the ESC measures and limits on the Treesdale parcel (61 -182) does not necessitate
any modification to the ESC bond. However, depending on the resolution achieved after the
meeting suggested in comment Cl, the limits of disturbance of the ESC plan will need to be
reduced and a bond reduction would be justified.
File: EI_mia esc swm_PBC_wpo2Ol OOOO78- sdp2Ol OOOO91 Treesdale Amendment.doc