Phase MI-4B Dead Loop Restoration
urban flood control
Minot's existing flood protection system, originally designed and constructed by the US Army Corps of Engineer (USACE) in the 1970's, is primarily a channelization project. The USACE straightened and widened sections of the river to increase the conveyance capacity of the system. In the process, several meanders of the Mouse River were intentionally cut off, creating historical channel areas that are isolated from the main river channel.
These former river meanders serve as ponding areas for interior drainage during a flood event. When a flood threat arises, gates on the upstream and downstream ends of these storage areas are closed. During ordinary flows on the river (ie non-flood situations), the gates are intended to remain open to allow some water from the Mouse River to pass through these historical meanders, the USACE also constructed weirs on the main channel of the river. The intent of the weirs was to cause the water on the upstream side to increase in elevation, thereby forcing more water through the former river channel when the gates are open.
These components of the system, while well-intentioned, do not function well. The nature of the gates, weirs, and flows allow only for limited water conveyance through the historical river channel, and the gate structures (with submerged inlets) act as skimmers, trapping floating materials. Additionally, the interior drainage systems convey urban storm water and associated sediment to these historical meanders. But without adequate flows through the channel, the sediment is not flushed to the main river system and is allowed to accumulate,
The unfortunate result is that the historical meanders trap sediment on the bottom of the water column and floating debris on the top of the water column. The conveyance capacity of the channels is further deteriorated, and the single resource that keeps these sections of natural river channel ecologically viable (ie oxygenated, flowing water) is further restricted. This results in degraded water quality, algae blooms and propagation of duckweed. The stagnant water within these historical meanders is also odorous. Locals have coined the term 'dead loops' to describe these historical meanders. There are several dead loops within the city of Minot. These include Oak Park, Nubbin Park, Eastwood Park, Roosevelt Park, and Green Valley.
The dead loops are an unsightly characteristic of the Mouse River valley in Minot. Another alternative exists that would restore the ecological qualities of the historical meanders of the Mouse River and create a recreational waterway through a large segment of the City of Minot. Interior drainage benefits associated with storing local runoff from rainfall events that occur while the Mouse River is at flood stage would also be maintained. Instead of burying the dead loops, this solution would resuscitate them. These efforts will also satisfy reclamation requirements from the USACE.
Once complete, the waterway would begin at the 16th Street Southwest bridge near the water treatment plant and extend downstream through the resuscitated sections of Oak Park, Nubbin Park, Eastwood Park, Roosevelt Park and ultimately Green Valley.
The first phase will include the Oak Park dead loops and is currently in the design phase. The map below shows the entire waterway once complete.
Current Conditions, City of Minot Dead Loops
Current Conditions, City of Minot Dead Loops
Current Conditions, City of Minot Dead Loops