Brian Welch, GIS Technician for the City of Northfield, has this update in Northfield City Administrator Joel Walinski’s June 25 Friday Memo:
Stormwater Pond Rehabilitation Assessment
The City has contracted with Barr Engineering to help the city develop a prioritization of stormwater ponds in need to dredging and other rehabilitation work to improve management of surface runoff.
Six ponds have been designated as the initial priority based on the presence of significant sediment plumes, vegetation growth, or deteriorating storm pipes: John North Park, Grant Park, Hidden Valley Park, Sibley View ponds (north of Jefferson Pkwy to the east and west of Washington St S), and the small pond to the west of Heywood Rd. between Sunset and Creek Lane.
The week of June 28 survey crews from Barr will be mapping the bathymetry of the ponds and determining the elevation of inlets and outlets to the ponds. State regulations require testing of sediment samples from the pond in order to determine whether special treatment is required of dredged materials. Barr Engineering will conduct the core sampling and testing in coming weeks. Once the pond assessments are complete a rehabilitation plan and schedule will be developed for each pond.
Funding for the pond assessments and rehabilitation comes from the city’s stormwater utility fund. The city will continually work through the inventory of stormwater ponds to ensure proper functionality of the ponds as part of the citywide stormwater infrastructure.
It should be noted that treatment of stormwater is the priority function of these ponds.