HomeMy WebLinkAboutWPO201100051 Review Comments Stormwater Management Plan 2011-11-17COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project:
Country Green Cottages SWM Amendment (WPO- 20 1 1- 0005 1)
Owner:
Mr. Dale Ludwig
Applicant:
Mr. Tim Miller, PE; Meridian Planning Group, LLC
Plan received date:
18 July 2011
(Rev. 1) 31 October 2011
Date of comments:
23 August 2011
(Rev. 1) 17 November 2011
Reviewer:
Phil Custer
The first revision to the SWM Amendment for Country Green Cottages (WPO- 2011 - 00051), received 31
October 2011, has been reviewed by engineering. The following comments must be addressed in order to
receive plan approval:
1. The incoming pipe is in a different alignment than the approved plan. Is this current pipe location
based on the as -built condition?
(Rev. 1) Comment has been addressed.
2. The county will grant a variance for the downstream slope of 2.5:1 (steeper than the 3:1 standard)
if a 2.5:1 slope is applied to the upstream slope of the embankment in keeping with the 5:1
standard as outlined on VSMH 3.01 -13.
(Rev. 1) Comment has been addressed. Both embankment slopes are now 2.5:1. However, with
the changes required to address comments 2 and 3, a retaining wall has been added to the
embankment. While retaining walls in SWH embankments are questionable, the previous
SWHplan was approved with a much larger retaining wall in the embankment and, therefore,
no further modification is necessary.
3. The width of the embankment is not adequate. The embankment detail states that the provided
width is loft, but this width is only accurate for the distance between the 488 contours.
Embankment widths must be measured at the top elevation, 488.8.
(Rev. 1) Comment has been addressed. The embankment width is now ]Oft. However, with the
changes required to address comments 2 and 3, a retaining wall has been added to the
embankment. While retaining walls in SWH embankments are questionable, the previous
SWM plan was approved with a much larger retaining wall in the embankment and, therefore,
no further modification is necessary.
4. Please provide horseshoe - shaped gravel rings around the two inlets to create makeshift forebays.
This will not affect any of the water quality or water quantity calculations.
(Rev. 1) Comment has been addressed.
5. Please provide Top of Wall and Bottom of Wall spot elevations for the new wall.
(Rev. 1) Comment has been addressed.
6. The plan shows disturbance to the neighboring property, TMP 76 -52J3. Also, disturbance is
needed to this property to apply a roofdrain system on the back gutters to drain to the biofilter.
Please provide a signed letter from the owner of this lot consenting to the grading shown on the
plan and the construction of the roofdrain system implied in the approved SWM plan.
(Rev. 1) The county is still waiting on a letter from the adjacent owner for the connections of
the roofdrains to the biofilter.
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Albemarle County Community Development
Engineering Review Comments
Page 2 of 2
Please provide a landscape schedule on sheet C -101. Also, it appears more plants are needed to
meet the state's 10 plants per 1000sf guideline. [VSMH 3.11 -20]
(Rev. 1) Comment has been addressed.
The outlet protection at the end of the barrel seems to have significantly eroded in the last several
years. The design of this outlet should be reexamined to discover a more stable solution.
(Rev. 1) The area of the site I was referring to was the outlet of the stormwater facility, not the
outlet of the road drainage system, though there is erosion occurring at both locations.
Provide a detail for the pipe outlet through the wall.
(Rev. 1) Comment has been addressed.
Please replace "Luck Bio- Filter Mix or approved equal" with "State Approved Mix" wherever the
Luck mix is specified.
(Rev. 1) Comment has been addressed.
11. The SWM bond will be recomputed at the time of plan approval and the applicant will need to
post it in order to construct the facility.
(Rev. 1) It has been determined that no modification to the bond is necessary.