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North Ottawa Impoundment Project
Description/Location:
The impoundment will control 75 square miles of the 320 square mile
Rabbit River Watershed in Grant and Otter Tail Counties by storing
the excess runoff on 1,920 acres of land. The project involves
constructing dikes around the perimeter of the impoundment area,
building a collection system to bring water into the impoundment,
and partitioning the interior to provide a complex of
subimpoundments. Waters carried by existing drainage ditches will be
intercepted by diversion channels, and brought into the impoundment
through a diked inlet channel. The impoundment will have 100% of its
storage capacity available for the spring runoff. After spring
runoff, the water will be released as quickly as possible to restore
about 80% the impoundment’s capacity. The remaining 20% will be
drawn out slowly over the balance of the year while providing the
secondary benefits.
Project Benefits:
Flood Damage Reduction (Primary objective): Provides 16,000 acre
feet of gate-controlled storage which is equivalent to 75% of the
estimated 100 year spring runoff. This is expected to reduce peak
flows on the Bois de Sioux River at Wahpeton/Breckenridge by about
5%.
Downstream Flow Augmentation: Release of about 5 cfs flow during the
ice free season in most years.
Water Quality: Improvement via sedimentation and nutrient uptake by
wetland plants
Habitat Enhancement: Feeding and resting areas for migrating
waterfowl and shorebirds and stream flow maintenance for downstream
fish habitat.
Problem Description:
Flooding: Local-10 to 15 square miles of ag land flooded frequently;
Regional - Wahpeton/Breckenridge urban flooding; Farmstead,
machinery and grain storage damage
Erosion and Sedimentation: Streambank and sheet erosion, Streambed
sedimentation.
Other: Loss of wildlife habitat due to intense agricultural
activities
Partners:
• Red River Watershed Management Board
• State of Minnesota
• Bois de Sioux Watershed District
• US Fish & Wildlife Service
• Minnesota Department of Natural Resource
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MN DNR
waterfowl video from the 2010 spring run-off; named "Winged
Prairie"
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North Ottawa Impoundment
2011 Hydro Report
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