HomeMy WebLinkAboutWPO200800042 Review Comments Road Plan and Comps. 2008-06-06ALg�,��
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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: WPO- 2008 - 00042, Avon Court
Plan preparer: Mr. Scott Collins, PE; Collins Engineering fax 434.245.0300
Owner or rep.: Avon Court Holdings, LLC fax (unknown)
Date received: 23 April 2008
Date of Comment: 6 June 2008
Engineer: Phil Custer
The SWM, ESC, and road plans for Avon Court, received on 23 April 2008, have been reviewed. The
plans cannot be approved as submitted and will require the following corrections before approval can be
granted:
A. General Review Comments
1. For the ESC plan, construction operations appear to take place on TMP 77 -7. Please provide a
letter of intent from the property owner. The permanent easement on this property will be handled
through the ACSA review process.
2. Please note that State Route 742 is Avon Road and not Avon Court. Please change this state route
number on all sheets.
3. Please provide letters from the property owners of TMP 77 -9, TMP 77 -9A, and TMP 77 -8C
acknowledging that access to their site will be limited during the road construction operation.
VDOT approval may eliminate this comment.
4. A letter of intent from the owner of TMP 77 -9A is needed for the construction of the parking lot
entrance.
5. Stream buffers in the development areas are independent of the floodplain. Please adjust the plan
to correct this.
6. Please amend note 1 on Sheet E -I to match the floodplain note on the cover sheet.
7. Please state the datum the topography was generated from on the plan.
8. At Sta. 13 +50, there is a paved area with a culvert that is not shown or accounted for on this plan.
B. ESC Plan Review Comments
1. Please provide adequate channels for all temporary and permanent discharge points. It appears
adequate channels are needed from trap #2 and the bioiilter /trap #1. Easements will be needed
along these channels as well.
2. Please provide a second construction entrance at the beginning of the work on Avon Court and
provide a note on the plan that this construction entrance is only to be implemented during the
construction of the roadway from Sta. 12 +50 to Sta. 18 +00.
3. Silt fence on the southside of Avon Court is not an acceptable measure because it is placed across
contours. It appears that a diversion leading to a sediment trap would be a more appropriate
measure to treat this part of the construction. Please provide a letter of intent from the owners of
TMP 77 -8C to allow these construction operations to take place.
4. Please state specifically on the ESC plan how the upgrade of the roadway between Sta. 12 +50 and
18 +00 will be carried out to minimize access issues to TMP's 77 -9, 77 -9A and 77 -8C.
5. The post development drainage area to sediment trap #1 is greater than 3 acres and should be
designed as a sediment basin. The drainage area that I found using a planimeter was somewhere
between 3.5 to 3.75 acres depending on drainage line on a fully - constructed Avon Court that is not
shown correctly on sheet ESC -2.
6. The graded slope northwest of sediment trap #2 needs an ESC measure.
7. Please extend the diversion east of sediment trap #2 to capture the existing roadside swale
drainage. It appears that a grading easement exists in this area already.
8. There are areas within the limits of disturbance that are not protected. Please amend the limits of
disturbance or adjust ESC measures to protect all disturbed areas.
9. Will the concrete and waste areas located on TMP 77 -7 be removed with this plan? If not, please
clearly show the limits of construction and the existing concrete and areas to remain on the ESC
plan. If so, please provide protection measures for this work and a letter of intent from the
property owner.
10. In trap 1, all slopes above the wet storage must be at least 2:1.
11. Please adjust the calculation sheet of trap #2 to indicate the bottom dimension is 13' x 58'.
12. In all of the lots, please replace temporary seeding symbols with permanent seeding symbols.
13. The ESC portion of the WPO bond will be computed once all comments have been addressed.
14. Please note that a grading permit will be withheld until a copy of the state VSMP permit is given
to the county. Please contact Mr. Matthew Grant, DCR, at 804.225.3068 for more information.
C. SWM Plan Review Comments
1. A signed Stormwater Management Facility maintenance agreement and recordation fee will need
to be submitted. Please contact Pam Shifflett (x 3246) for questions regarding this procedure.
2. Engineering is only reviewing the SWM plan for the proposed construction of the extension of
Avon Court. There will be no future impervious area credit granted with this approval. On sheet
SWM -1, please remove the statement "It also demonstrates the ultimate development of the
parcels can achieve stormwater detention and quality." As always, the applicant may oversize
their facilities at his discretion but, as noted on the plan, additional SWM reviews will be required
for each future development plan.
3. Please remove all "conceptual" stormwater management facilities and conveyance systems that
will not be constructed with this road from the calculations sheet.
4. The downstream slope of the embankment should be constructed with 3:1 slopes.
5. All slopes steeper than 3:1 will require a low maintenance, non - grassed groundcover. This
requirement is also enforced around biofilters.
6. The SWM access road should be shown as loft on the detail on SWM -2. Gravel is not required
unless the slopes are greater than 10 %.
7. The maximum ponding depth allowed in biofilters is lft. Please adjust bioiilter elevations.
8. Please change all callouts for Luckstone bioiilter mix to "state approved mix."
9. On the embankment detail, please show the cutoff trench into existing grade as it appears in Figure
3.01 -1a.
10. Please provide a planting schedule for the bioiilter. The planting plan should be designed
following the recommended specifications in the VSMH MS 3.11.
11. It appears a permanent SWM easement will be needed on TMP 77 -7 for the underdrain. An
easement for this must be recorded before a grading permit will be given.
12. The detention calculations do not appear to route the critical storm duration. I do not see how
there could not be any discharge from the bioiilter during the 2 -year and 10 -year critical storms. A
detention waiver could possibly be granted by the program authority. If desired, please submit to
me a justification letter citing any of the reasons listed in Section 17 -314G and I'll discuss the
issue with Glenn. On occasion, projects within close proximity to floodplains have been given
waivers for detention, but flooding of Moore's Creek is a well -known issue and a waiver may not
be granted in this watershed.
13. The underdrain inlet elevation is incorrect.
14. The SWM portion of the WPO bond will be computed once all comments have been addressed.
D. Road Plan Review Comments
1. VDOT approval is required. Comments will be forwarded at the time they are received.
2. Please show all entranceways and parking lots of all of the sites affected by the road
improvements.
3. Please provide horizontal curve information on the plan.
4. Please provide marks at all +50 stations. [DM]
5. Please show and label all traffic control signs on the plan.
6. Please label all curb radii on the plan.
7. Pipes 11 and 9 must be a minimum 15" in diameter.
8. Please show outlet protection on the storm profile as well.
File: El_esc swm rp_PBC_08 -042 Avon Court