HomeMy WebLinkAboutSDP200600079 Review Comments Major Amendment, Final Site Plan 2010-11-19*-&A
County of Albemarle
Department of Community Development
Memorandum
To: Megan Yaniglos, Current Development Project Planner
From: Phil Custer, Current Development Engineer
Date: 19 November 2010
Subject: Berkmar Business Park Major Site Plan Amendment (SDP- 2006 - 00079)
The major site plan amendment, received on 23 September 2010, has been reviewed. This is the fourth
submittal of the plan to the county. From the review of the previous comment letters, all reviews
performed have been to preliminary site plan requirements for the Site Review Committee process. As
discussed in emails between county staff, the applicant, and the applicant's consultants in January of 2009,
it was clarified that a review of the plan to final site plan standards is desired. Engineering will continue
with comments as written by John Sharp in his 12 June 2008 memo with additional final site plan
comments added to the end. Please note that no WPO application and fee have been provided and
therefore only a conceptual review of the SWM plan has been performed. Stonehaus had been informed of
this need via email on 4 October 2010. Engineering review for current development can recommend
approval to this application after the following changes:
1. Upon a field visit to the site by County Engineering, the channel between the UVA Credit Union
and the site appears to be a perennial stream (beginning directly below the culvert outlet of
Berkmar Drive). Also, there appears to be another perennial stream between the site and Kegler's
property (beginning at a spring on the property line: fence at elevation 482, 165' N of the site
property corner). A stream assessment should be provided to determine whether or not the streams
are perennial. If the streams are perennial, there will be a 100' stream buffer on the banks of both
sides of the stream. This would significantly alter the permitted development on the site.
(Rev. 3) I will accept the developer's consultant's findings that the stream along the southern
border of the parcel is not perennial.
2. In regards the spring on the property line near the fence, the existing spring may have been
originally located further up within the site (based on looking at old topo) and was french - drained
to its current location. It could be located between the fence and existing go -kart building, or even
higher up. You may want to field locate the spring.
3. Upon a field visit to the site, the existing topography does not appear to match the plans. For
example, the existing bumper boat pond has been removed and filled in. Please provide accurate
existing topography.
(Rev. 3) If the only discrepancy between the survey and field conditions is the filling in of the
pond, I agree that a new survey does not need to be updated. However, because of the nature of
the developed parcel, the esc plan will be more sensitive to discrepancies. Please be advised that
if further discrepancies are realized in the field during construction, a stop work order may be
issued until the ESC plan is redesigned to accommodate the field conditions.
4. Proposed critical disturbance is shown in potential stream buffer areas. Engineering recommends
delaying pursuit of a critical slopes waiver until all stream buffer issues have been resolved.
Engineering cannot recommend approval of a critical slopes waiver until the stream buffer issue is
resolved.
(Rev. 3) A critical slope waiver is still needed in order for this site to be developed as proposed.
Please note that since the latest submittal, a zoning ordinance amendment was passed by the
Board of Supervisors that states all man -made slopes (defined by slopes shown to be
Current Development
Engineering Review Comments
Page 2 of 4
constructed in a county approved site plan) must waived by the Chief of Current Development.
In preparing this waiver request, please refer to Section 4.2.5 of the Zoning Ordinance. Please
also review the previously approved site plan and confirm that all disturbed critical slopes were
shown as being constructed on that plan. If any portion of the disturbed critical slopes is not
shown on the previous site plan, the waiver request must be approved by the Planning
Commission.
5. Not all critical slope disturbances shown are man -made critical slopes. A critical slopes waiver is
needed for the proposed grading for the dumpster pad within critical slopes below contour 496. It
appears that this critical slopes disturbance could be avoided by altering the layout of the dumpster
pad. Also, a critical slopes waiver is necessary for any grading on first 20 feet on the Kegler's
property within critical slopes.
6. (Rev. 3) A critical slope waiver is still needed in order for this site to be developed as proposed.
Please note that since the latest submittal, a zoning ordinance amendment was passed by the
Board of Supervisors that states all man -made slopes (defined by slopes shown to be
constructed in a county approved site plan) must waived by the Chief of Current Development.
In preparing this waiver request, please refer to Section 4.2.5 of the Zoning Ordinance. Please
also review the previously approved site plan and confirm that all disturbed critical slopes were
shown as being constructed on that plan. If any portion of the disturbed critical slopes is not
shown on the previous site plan, the waiver request must be approved by the Planning
Commission.
The dumpster grading should also be revised to keep water from running across the pad as
required by I8- 4.12.19.b. I recommend the applicant consider adding a CG -3 at the edge of the
pavement.
7. Please show the critical slopes shaded on the grading plans for clarity. Other than the slopes
mentioned in comment #4, the remainder appear to be man-made (shown on previously approved
site plan), but it is difficult to tell. All critical slopes shown as created by a previously approved
site plan do not require a critical slopes waiver.
(Rev. 3) The slopes have been shown on the grading and utilities plan as requested. However, a
critical slope waiver is still needed in order for this site to be developed as proposed. Please note
that since the latest submittal, a zoning ordinance amendment was passed by the Board of
Supervisors that states all man -made slopes (defined by slopes shown to be constructed in a
county approved site plan) must waived by the Chief of Current Development. In preparing this
waiver request, please refer to Section 4.2.5 of the Zoning Ordinance. Please also review the
previously approved site plan and confirm that all disturbed critical slopes were shown as being
constructed on that plan. If any portion of the disturbed critical slopes is not shown on the
previous site plan, the waiver request must be approved by the Planning Commission.
Many critical slope areas are not properly shaded on the plans. There appears to be a larger area
on the western portion of the site not shown properly.
(Rev. 3) Comment has been addressed.
8. The grading in the western corner of the site for proposed contours 502 and 504 is confusing and
does not appear to be necessary.
(Rev. 3) Comment has been addressed.
9. The grading in the eastern corner of the site proposed contour 480 is confusing. Either grading is
cut off or the proposed grades do not tie into existing grades. Show all proposed grading on the
grading plan. Also, existing topography shown 50' beyond all proposed grading is requiredon the
grading plans.
(Rev. 3) The 478 contour is now confusing. It makes sense to eliminate one of the parallel 478
contour lines.
Current Development
Engineering Review Comments
Page 3 of 4
10. Grading is shown within the existing SWM facility. Any grading within the facility will require
updated SWM plans and calculations for the basin.
(Rev. 3) The filling within the facility will be reviewed with the Stormwater management plan
after a WPO application has been submitted.
11. All pipe outlets and stormwater facility outlets require adequate channels tying into the
streams /channels below in addition to outlet protection. Providing only outlet protect is
inadequate. For example, when existing OF -I was constructed, no out letting ditch was provided,
only outlet protection was installed, and as a result all of the outlet protection was blown out into
the channel below and there are now erosion problems occurring in this area.
(Rev. 3) This is an erosion control issue that will be commented on after a WPO application has
been submitted. Generally, it appears adequate channels from the outlets to the detention
facility appear to still be an issue.
12. The proposed plans specify wetlands to be filled over and removed. Engineering could not find
wetlands in the location specified on the plans during a field visit to the site. Possibly the wetlands
are located in the area where the existing spring is located? Please clarify.
(Rev. 3) Please forward approval from the Army Corps of Engineers and /or Virginia DEQ for
the disturbance to the wetlands as noted above.
13. Easements, or at a minimum, letters of intent are required for all offsite work. It appears
easements are needed from the UVA Crediut Union, Lowes, and Kegler's.
(Rev. 3) Offsite easements must be recorded prior to site plan approval. A letter of intent will
not be adequate for final site plan approval.
14. Please provide an interconnection to TMP 45 -112.
(Rev. 3) Please show a constructed connection to the property. For the purposes of this site
plan, the connection can simply be the western connection. At the time the certificate of
occupancy is requested the Zoning Department will decide whether this connection is built or
removed depending on the status of the rezoning plan for the adjacent parcel.
15. Please provide removal rate calculations and drainage area maps for each BMP structure. Will the
proposed SWM facility be a biofilter? The plans do not specify.
(Rev. 3) Removal rates have been provided. The stormwater narrative refers to the biofilter
facility as treating at 65% (lin of runoff) but states that the sizing is based on only the new
impervious area to this facility. Because the removal rate as computed by the applicant is 35°Ic,
a facility with this removal rate or greater must be designed for the entire 1.60 acre watershed
and its subsequent water quality volume (69.9cy). The applicant's narrative states that within
the first Ift of depth within the biofilter 48.4cy is treated. This indicates an undersized facility.
However, the county accepts the bed area ratio as specified on page 3.11 -9 of the VSMH. In
conclusion, the biofilter bed must be 1133sf (I.6acres x 0.65 x 43560sf x 0.025) with Ift of
ponding. All other stormwater comments will be provided when the WPO application and fees
are submitted.
16. It appears the existing Kegler's detention basin is designed to detain this site up to a C -value of
0.75 for TMP 45 -112, 112G, and 112GI. Any development beyond 0.75 must be handled with
additional detention.
(Rev. 3) The overall C for the developed area of the project (not the property limits) appears to
be 0.764. However, because the detention is being provided in the biofilter, the impervious area
ratio of the development is acceptable but the reduction of basin volume will need to be
reviewed more thoroughly with the WPO Plan.
17. The proposed sidewalks south of buildings I and east of the existing building are shown at a
crossslope of 20 -25 %. This does not appear to be safe.
(Rev. 3) Comment has been addressed.
18. Please provide a benchmark for topography.
Current Development
Engineering Review Comments
Page 4 of 4
(Rev. 3) Comment has been addressed.
19. Please provide traffic generation figures.
(Rev. 3) Comment has been addressed.
20. Guardrail is required for all parking areas adjacent to steep slopes or drop offs.
(Rev. 3) Comment has been addressed.
21. Any retaining walls in excess of 4 feet in height must specify safety railing.
(Rev. 3) Comment has been addressed.
22. The 5 proposed spaces south of the existing building are only shown at 17.5 in depth. The spaces
must maintain 18' in depth.
(Rev. 3) Comment has not been addressed. The dimensions would be acceptable (because of
the 6ft sidewalk) if the bumper blocks in these spaces are eliminated.
23. Parking spaces cannot extend over a property line, unless a shared parking agreement is provided.
(Rev. 3) Engineering will defer to the Community Development Planner with the review of this
comment.
24. Parking areas cannot exceed 5% in slope in any direction.
(Rev. 3) Comment has not been addressed. The parallel parking along the northern travelway
is steeper than 5%. Please either eliminate these spaces or request a waiver to the Chief of
Current Development per I8- 4.12.2. c. There are also a few slopes steeper than 5% in the
parking lot south of Building 2.
25. All slopes steeper than 3:1 must be stabilized with low maintenance non grassed ground cover.
(Rev. 3) The Pennsylvania Sedge is an acceptable low maintenance ground cover. However,
the slopes steeper than 3:1 on the eastern end of the property do not show this planting as
required.
26. The proposed SWM facility requires forebays at each location of concentrated discharge into the
facility.
(Rev. 3) Comment has been addressed.
27. (Rev. 3) A storm sewer inlet appears to be needed —30ft downstream if MHA3 in the corner of
the row of parking.
28. (Rev. 3) Is the concrete pad detail KIM intended to be a specification for the dumpster pad? If
so, I recommend a stronger standard.
29. (Rev. 3) Details AIM and B 114 appear to be the same standard. This standard (6" of gravel and
2" of pavement) has limited strength and is not adequate for the main travelway from the
entrance onto Berkmar Drive to one of the interdevelopment connectors north of Building 2.
Please provide an estimate of the ADT after full development in the area (assuming all
proposed connections to the rezoned parcel) is completed and design the main travelway
pavement considering this load.
File: E4_finj_PBC_sdp200600079.doc