The City of Anoka is proposing to excavate the sediment deposits out of the “lagoon” area within the Rum River, located just north of the Burlington Northern Santa Fe railroad tracks and the Anoka County Rum River Human Services Center (west of 4th Street and east of the Rum River).
Sediment has accumulated within this area from an old stormwater pipe outlet.
All stormwater in this watershed is now (since 2009) routed through the storm water pond east of this area, which intercepts the vast majority of sediments currently.
The City contracted Hakanson Anderson in 2012 to complete a survey of the lagoon area to determine the amount of sediment present and how much would need to be removed to restore the lagoon area back to “historic conditions.”
The survey determined up to 1.9 feet of sediment was located in the northern portion of the lagoon and a total of 2,000 cy is estimated to be excavated (surface area is 0.35 acres).
The sediment deposit removal will be accomplished via excavator or backhoe.
This work is expected to occur in the winter when surrounding soils are frozen and can support equipment used for excavation, unless otherwise advised by the regulatory agencies. By removing the sediment, it will restore the lagoon back to native soils and will also allow for canoes and kayaks to access the Rum River through the lagoon.
The lagoon area will have enough depth for a small watercraft (pontoon, paddle boat, etc.) to access and use the proposed dock structure.