English Coulee Water Quality Renewal Plan

The English Coulee meanders through Grand Forks, North Dakota and has many important uses to the City not only drainage and interior flood protection storage but also pedestrian walking / biking corridor and active recreation opportunities such as ice skating and paddling. Given that the English Coulee serves a watershed over 50 square miles that is dominated by agricultural land use, the coulee has been plagued by issues related to E coli and phosphorous. Further, as Grand Forks continues to grow, urban runoff quality is also providing significant loading. Finally, a significant hydrologic / hydraulic alteration to the English Coulee was made about 20 years following the catastrophic 1997 Red River flood that destroyed much of the City - the English Coulee Diversion was constructed as part of the interior flood protection system that aids in protecting the City from Red River floods. This diversion cuts off much of the agricultural watershed but also reduces the potential for high springtime flows to flush sediment and nutrients that have accumulated in the coulee within the City. The stagnant water conditions throughout much of the summer combined with the likely high nutrient concentrations create severe aesthetic and odor issues related to algal blooms and anoxic conditions. While the coulee is listed as an impaired 303(d) waterway, the City decided to begin their own multi-phase initiative to renew the coulee given its benefit to the community as a recreational resource. The first phase of the project focused on answering the question 'what could be done?'. To answer this question, the first phase involved three key components: 1) public outreach and engagement, 2) water quality monitoring and modeling, and 3) hydrologic / hydraulic monitoring and modeling. A unique approach to public engagement was used with signs along the coulee with QR codes that pedestrians could scan and bring the online survey up on their phones. The public engagement survey received over 500 responses with an overwhelming response that the community wanted to see the Coulee's water quality improved. Water quality monitoring was also completed for numerous parameters that confirmed the community's observations nutrients (namely phosphorous), suspended sediment, and E coli were all very high throughout the year. Water level data was also collected at several locations that indicated that FEMA's hydrologic and hydraulic analysis did not reflect the complexity of the coulee hydraulics, illustrating the need to create a more robust hydrologic / hydraulic model of the coulee system to evaluate potential watershed and channel / dam modifications. The second, ongoing phase of the English Coulee Renewal Plan aims to answer the question 'What should be done?' with subsequent phases aimed at implementing projects to improve water quality in the coulee.