HomeMy WebLinkAboutSite Certifications - 07/11/2012./
January 16, 2012
Mr. Jay Barber
City of Fort Collins
Storm Water Utility
700 Wood Street
Fort Collins, CO 80521
Re: Water Quality Pond and Drainage Certification for Lindenmeier Estates Subdivision
1R Project # 39090.00 and 39679.00
Dear Mr. Barber,
The purpose of this letter is to describe the as -built characteristics of the storm water quality treatment
pond known as Pond A in the Lindenmeier Estates Subdivision and serve to request acceptance of the
facility by the City. As previously mentioned in our variance request letter, dated April 30, 2008,
Pond A is one of two ponds treating storm water runoff from the subdivision and the second pond,
Pond B, has already been accepted by the City. The purpose of the 2008 letter was to modify the
design of Pond A using the criteria for a Porous Landscape Detention Pond, PLD, as outlined by the
Urban Storm Drainage Criteria Manual. After meeting with Basil on site and discussing the design,
the PLD was constructed, but for reasons unknown, not certified. On January 3, 2012, JR Engineering
inspected the pond and reviewed the as -built facility for conformance with the design. The stormwater
facilities appear to be in general conformance with the approved plans and drainage design. The
required storage volume is provided.. The under drain, porous media, filter fabric also appeared to
have been constructed per plan.
Variations from the design were minimal and typical of construction projects. The vegetation had not
yet been established. The owner's representative stated that they will be finishing landscaping in the
spring. Also, there was not an orifice in the control plate where the unde rdrain connects to the outlet
structure. An orifice was sized following the equations for PLD design in the USDCM. The orifice
was added to the plate and re -installed.
In conclusion, based on field observation and our volume calculations Pond A was constructed in
general conformance with the approved plans. I find that the storm system as built, should operate as
designed in the approved final drainage report. If you have any questions or comments, please contact
me at 970-222-1317.
Meyers Jr., P.E.
ject Engineer/Surveyor
Engincerma