4.b) Engineer's Memo September 30September 30, 2015
Sherri,
From the pictures you have shared, it appears the driveway is not flat and has a gentle slope towards
205th Street.
Each rain event that occurs, some level of sediment flows directly to the curb and downstream until it
eventually enters a storm structure and then conveyed to a pond. Circled in red below appears to show
evidence of water flowing/gravel erosion in this picture that was provided as you can see the difference
in surfaces on the other side of the driveway.
If the City wants to reduce this sediment loading that is occurring, at a minimum a bituminous or
concrete driveway apron shall be constructed and minor regrading of the driveway to have the
remaining gravel portion drain into the grass to act as a buffer.
If the curb and gutter were not present, there most likely wouldn’t be the same concerns as outlined.
Also, if the driveway is flat and the pictures just appear to show a slope as described above then the
erosion would be less of a concern as well. The City Engineering Standards do not specify type of
driveway, but rather just dimensions.
Thanks,
Ryan J. Goodman, P.E.
Senior Project Manager
Bolton & Menk, Inc.
Consulting Engineers & Surveyors
2035 County Road D East, Suite B
Maplewood, MN 55109
Mobile: (612) 597-7140
Fax: (651) 704-9971
email: ryango@bolton-menk.com
www.bolton-menk.com