HomeMy WebLinkAboutWPO201500025 Review Comments As-Built Reviews 2016-08-30 434.293.3719 PH 434.293.2813 FX
www.collIns-engineering.com
August 30,2016
Albemarle County
Department of Community Development
Engineering Division
401 McIntire Road, Room 227
Charlottesville,VA 22902-4596
RE:Asbuilt Plan for WPO 201500025
An asbuilt survey for WPO 201500025 has been performed for the bioretention basin.The survey was
completed predominantly by a third party consultant and is shown with the attached CMA Properties
Construction Record Drawing.
Upon reviewing the data provided by Cardinal Survey&Design and conducting an onsite investigation of
the facility,Collins Engineering asserts the facility was constructed in reasonable conformance with the
approved plans.The asbuilt survey confirms the installation of a riser,barrel and emergency spillway
outfall system.The attached record drawing also confirms the installation of riprap channel protection,a
forebay,a detention cell,mulch bedding and numerous cleanouts for the underdrains. Landscaping was
also installed and verified by Collins Engineering on August 29, 2016.
Below is a summary of the findings:
Approved Riser Approved Riser Outlet
Riser Diameter 24" Barrel Diameters 15"
Riser Rim 491.75 Barrel Length(Total) 276'
Low Row Orifice Diameter 4" Invert at Riser 481.38
Low Flow Orifice Invert 484.00 Invert at Outfall 480.00
Three PrMdflow Orifice Diameters 4" Slope 0.50%
Three Midflow Orifice Inverts 488.00
Asbuilt Riser Asbuilt Riser Outlet
Riser Diameter 24" Barrel Diameters 18"
Riser Rim 49198 Barrel Length(Total) 246
Three Low Row Orifice Diameters 4" Invert at Riser 48180
Three Low Row Orifices Inverts 485.24,485.24 and 485.17 Invert at Outfall 480.86
One Iv&dflow Orifice Diameter 4" Slope 0.3=
One Ividflow Orifice Invert 488.58
The applicant kindly requests this plan and letter be accepted to assist with the final release of the WPO
bond. •
to 19
Sincerely, '4`3Scott Collins, PE if::e
►( � Q'ITT R. COLLINS
2,6 Lie. No. 035791 ?