Blue Earth County Ditch No. 56

Lake Crystal, MN | Water


ISG partnered with Blue Earth County to develop a comprehensive inventory of recommended repairs and a Multi-Purpose Drainage Management (MDM) Plan to County Ditch Number 56 (CD 56), a 9-mile ditch system in need of restoration to improve nearby waterways affected by pollution from residential and agricultural runoff.


CD 56 had become an environmental concern as fertilizers from approximately 9,300-acre of farmland drained into Crystal Lake and other surrounding waterways.


Through collaboration with several stakeholders including Blue Earth County Drainage, Blue Earth County Soil and Water Department, the City of Lake Crystal, Crystal Waters Project, and local landowners, the County implemented ISG’s recommendation to install a phosphorus removal system for the Crystal Lake outlet; the first to be installed in Minnesota. The water filter removes up to 95 percent of dissolved phosphorus, reducing toxic algae blooms in area lakes, and improving water quality for Lake Crystal.

ISG’s water resource experts worked with Blue Earth County in their decision-making process to invest in the nutrient management system by completing an inventory of CD 56; inspecting 9 miles of open ditch utilizing photos and hand-held GPS units to precisely mark areas of interest. The inventory and topographic survey revealed that sediment, vegetation, and other obstructions were blocking flow, and in turn reducing the capacity of the CD 56 system. ISG prepared a report outlining a list of recommended repairs, which included open ditch cleaning, water and sediment control basins, a two-stage ditch, buffer seeding, and tile outlet repairs. Additionally, cost estimates and an MDM Plan to aid available funding were included for each option. Measures within the Plan were aimed at controlling sediment and water storage, minimizing nutrient loss, sustaining healthy soils, and increasing the ditch’s capacity.

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