HomeMy WebLinkAboutWPO201200062 Correspondence 2022-11-29 (2)SHIMP ENGINEERING, P.C.
Design Focused Engineering
October 20, 2022
Dan Ratzlaff
Manager of Engineering Compliance
Albemarle County
Dept. of Community Development
401 McIntire Rd
Charlottesville, VA 22902
Re: Engineer's Certification Letter — Old Trail Creekside — WPO201200062
Dear Mr. Ratzlaff,
I have reviewed the as -built surveys and conditions of the SWM Facility at Old Trail Creekside III Phase III,
WPO201200062.
• 1 hereby certify that the SWM Facility is constructed in an acceptable manner that meets the intent
of the approved plans dated 05-28-2013 with approval date 07-11-2013. While it is not constructed
exactly as proposed in the approved plans, the SWM Facility appears to be functioning as
designed. We report the following specifically.
o The pond size and shape are not constructed exactly per the approved plan; however, they are
constructed in a manner that meets the intent of the SWM Plan. This has been verified with
routing calculations.
o The pond side slopes are constructed per the approved plans.
o The rip -rap lined swale down the center of the pond is constructed per the approved plan.
o The top of the dam and the emergency spillway are each constructed 0.50-ft higher than the
approved plan, however the pond base is also constructed higher and the elevations meet the
intent of the SWM Plan. This has been verified with routing calculations.
o The primary spillway location material & dimensions are per the approved plan.
o The primary spillway orifices were constructed with a vertical separation of only 3.21-ft
whereas the plan proposed a separation of 4.0-ft. However, they are constructed in a manner
that meets the intent of the SWM Plan. The runoff is still released at rates compliant with the
stormwater regulations. This has been verified with routing calculations. Appropriate
trashracks have also been installed over each of the orifices.
o The primary spillway culvert is installed at approximately 120 off from the proposed location.
However, the direction is at a more gradual angle to the stream than proposed and therefore
does not cause any adverse effects. The material and size are per the approve an.
o There is adequate outlet protection at the culvert ouffall leading to the stream. /NO
� p,LTII OF
If you have any questions, please feel free to contact me at your convenience. JI
Sincerely,
Justin Shimp, P.E.
Shimp Engineering, P.C.
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N M. sM y
NO.45183
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