HomeMy WebLinkAboutSDP200800084 Review Comments Final Site Plan and Comps. 2008-07-07� 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: WPO- 2008 - 00057, Dunlora Gates E &SC, SWM and Road Plans
SDP - 2008 - 00084, Dunlora Gates Site Plan
Plan preparer: Mr. Mike Myers PE, The Engineering Groupe fax: 703.670.7769
Owner or rep.: Mr. Jim Gates fax: 434.263.4691
Plan received date: 21 May 2008
Date of comments: 7 July 2008
Reviewer: Phil Custer
A. General Review Comments
1. Please include the following on the plan: source of topography, date of topography, and a
benchmark.
Please provide confirmation of the grading easement on the open space adjacent to lot 394. A
letter or an email from the property owner will do.
Before this plan can be approved, drainage easements will need to be recorded from drainage
systems 10 -11 -12 and 9- existing. Storm structure 6 should be moved off of the property line;
otherwise, an easement will be needed in this area as well.
On the cover sheet, please update all standard county notes for general construction and
general construction for streets. These notes are available in the latest edition of the design
standards manual which can be found online.
B. Site Plan Comments (SDP- 2008 - 00084)
1. A drainage easement is required on the outfall of the biofilter to the stream.
2. A drainage easement is required on storm sewer system 6B -6A -6 and the upstream channel.
The width of this easement should be computed using the equation found in the design
manual.
3. Please callout a non - grassy, low maintenance groundcover in all areas where grades are
steeper than 3:1. [DM]
4. Please show the driveway on lot 394. The new sidewalk in this area does not appear to be
long enough.
5. The sidewalk on lot 16 should be angled towards the sidewalk crossing across the street
between lots 2 and 3. This crossing should also be angled towards the sidewalk on lot 16.
6. There should be a turn in the sidewalk on lot 384 directing pedestrians across the street
7. Inlet shaping (IS -1) is required on all inlets with a drop of water flow of 4ft or greater. This
fall requirement includes drops from the grate of an inlet as well.
8. The minimum deflection angle in a storm sewer system is 90 degrees. Please amend the
configuration on storm line 6B -6A -6 so that the deflection angle is greater than 90 degrees.
9. The drop connection shown in storm structure 3 is not allowed. Engineering review policy is
to have all grade and angle changes occurring in manholes.
10. The easement along the storm system 213-3 -4 should be widened based on the equation in the
design manual.
C. Road Plan Comments (WPO- 2008 - 00057)
VDOT approval is required. VDOT approval has not yet been received at the time of this
letter.
Albemarle County Community Development
Engineering Review Comments
Page 2 of 2
2. A crossdrain (CD -1) appears to be needed at Sta. 13 +40. [DM]
3. In addition to the proposed grade elevation, please include the existing grade elevation at each
50ft station in the profiles. [DM]
4. Please provide speed limit signs on the plan. [DM]
5. All driveways should be designed to conform to VDOT standard PE -1.
6. The following comments are typically reviewed by VDOT and, if approved by VDOT, do not
need to be amended to obtain county approval.
a. Some of the K- values appear to be steeper than the minimum value based upon the
design speed.
b. For rural road intersections, engineering review maintains a policy that the
intersecting cross street continue the 2% cross of the intersected primary street for at
least 20ft.
7. A new road bond will be calculated with this application. To request a road bond, the
applicant must complete a Subdivision Road Bond Estimate Request and a Schedule of
Completion for Bonded Improvements.
D. Erosion and Sediment Control Plan Comments (WPO- 2008 - 00057)
1. The diversion at the southern end of the property should be extended to the SW corner and pulled up
the western boundary to the construction entrance. This would satisfy engineering review's
requirement of construction entrances draining to trapping measures. The silt fence in the SW corner
would need to stay in place.
2. In phase II of the ESC plan, the back halves of lots 10 -15 do not appear to be adequately protected. A
trap or a diversion directing water to sediment basin 1 may be required.
3. The installation of the sanitary sewer line south of lot 395 will require ESC measures.
4. Please provide a staging and parking area on the plan. [DM]
5. Please provide a soil stockpile area. [DM]
6. In the narrative under "Critical Erosion Areas," please note that all areas steeper than 3:1 will require
low maintenanced, non - grassed groundcover. [DM]
7. The following comments are regarding the sediment basin calculations.
a. Barrel from sediment basin is mislabeled as 48" RCP in the detail.
b. Please provide stage - volume tables and volume calculations for the sediment basin.
c. An emergency spillway does not appear to be provided in plan view. Please provide a note
calling out the 8ft wide spillway on both sheets 9, 10, and 14.
d. Please submit dewatering orifice calculations. My calculations showed the orifice needed to
be 3" (rounded down from 3.8 ").
8. The ESC portion of the WPO bond will be computed once all comments have been addressed.
E. Stormwater Management Plan Comments (WPO- 2008 - 00057)
1. The maintenance agreement submitted with the original WPO was recorded with the property
and another agreement is not necessary. If a fee was submitted with this latest agreement
submittal, please let me know and I will refer you to correct person to obtain a refund.
2. Please show emergency spillway on sheet 14.
3. The gravel layer in a biofilter must be 1.5ft. [DM]
4. Please provide a planting schedule for the biofilter meeting the planting quanity requirements
of the VSMH. Please also be sure to specify at least 3 species of trees and 3 species of shrub.
5. The SWM portion of the WPO bond will be computed once all comments have been addressed.