North Ottawa Impoundment Project


Completed in 2016, the impoundment controls 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 involved 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 are intercepted by 10 miles of diversion channels, and brought into the impoundment through a diked inlet channel.

We have big plans for the impoundment, but are awaiting state agency approval. 

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%.

Monthly Photo Contest: May 2020 - October 2020

The Bois de Sioux Watershed District will be holding a monthly photo contest from May 2020 - October 2020. Each month, we will select one winner to receive $100.

Contest Rules:

  • Photos must be taken at the North Ottawa Impoundment in 2020.
  • The monthly deadline for submissions is midnight on the last day of each month. Photos must be submitted to:
  • All submissions will be evaluated by a panel of judges. All awards are made at the discretion of the judges, and their decision is final.
  • Participants may enter as many photos as they wish.
  • Individuals appearing in a photo give their consent to having their (or their minor children) photo taken, and for the photo to be used for any Impoundment-related purpose.
  • The District is not responsible for any technical issues related to photo submission.
  • District employees or Board managers are not eligible to enter.
  • By submitting photos, all photo contest entries become the property of the Bois de Sioux Watershed District. The Bois de Sioux Watershed District is granted the right to use these photos for any Impoundment-related purpose.
  • The Bois de Sioux Watershed District shall determine entry eligibility in its sole and absolute discretion.

  • Submissions will be deemed ineligible for the following reasons:

  • Images taken prior to January 1, 2020.
  • Photos that have been digitally altered beyond standard optimization (cropping, reasonable adjustments to exposure, color and contrast, etc.) will be disqualified.
  • Photos that violate or infringe upon another person’s right, including but not limited to copyright.
  • Images that involve putting any individual or wildlife in danger.
  • Downstream Flow Augmentation:

    Release of about 5 cfs flow during the ice free season in most years.

    Guage Readings are found here

    Water Quality:

    Downstream waters are improved through the reduction of sedimentation, nutrient removal by cropped interior farmlands, and stream augmentation - we will add a constant flow of water into the Rabbit River (especially important during summer and fall months, when there is naturally little to no-flow).

    Problem Description:

    Flooding occurs at two levels - locally within 10 to 15 square miles, and regionally in the Wahpeton/Breckenridge.  This project protects both rural and urban property and infrastructure.


    North Ottawa Photo Gallery: