Minnesota Integrated Watershed Study DNR Case Study

Study Highlights

•Paired Watershed Study Cty Ditch 29 - Impaired Cty Ditch 27 - Impaired Huse Creek – Unimpaired •Study Focus (Water Quality) Wetland loss and restoration Drained Depressional Lakes Impacts of Drainage Density and Improvements Impacts of Pattern Tile on flow & WQ

JD 29 (2010 Aerial Photo)

JD 29 GSSHA Grid

JD 27 (2010 Aerial Photo)

JD 27 GSSHA Grid

Shakopee Creek Study Goals

• Quantify hydrologic changes in watersheds (1950 to present) • Identify sources of impairments • Demonstrate benefits of installed BMPs • Apply Suite of BMPs to Mitigate Impairments • Quantify Effectiveness of “Targeted” BMPs • Inform Strategy to Clean-Up Lakes

BMPs

Minnesota River Basin

A History of Change

•Critical Economic Driver in Our Economy

•History of Drainage for Ag Productivity

•Cumulative Effect of These Changes Has Altered Hydrologic Balance

•Increased Nutrient and Sediment

•What Can We DO to Improve Water Quality While Minimizing Impact on Ag Production

Shakopee Creek, Chippewa River Basin

County Ditch 27 GSSHA Grid Draped Over Lidar Hillshade

Grid Cell Size: 30 meter (0.22 acres)

Drained Shallow Lakebeds

Circa 1938

Circa 1991

Depressional Lakes and Wetlands Drained for

Ag Production

Shakopee Creek Judicial Ditch 27 Drainage History

1991 Photo

2010 Photo

Wetland Restoration JD 29 North Branch

June 1997 Event Current Conditions Pre 1950 Conditions

Olson Wetland 2006

With Olson Wetland W/O Olson Wetland

1955 Photo

2010 Photo

Drainage Density/Improvements

Repair or Improvement?

Ditch side slopes 1:1.5

Ditch Side Slopes 1:2

Study Goals

Quantify Impacts of Drainage on Discharge, Sediment and Nutrient Delivery to D/S Chain of Lakes

Evaluate Benefits of Wetland and Shallow Lake Restorations on WQ

Evaluate Impacts of Climate on Hydrologic Response in a Changing Landscape

Explore a Suite of Ag BMPs to Mitigate Impacts of Hydrologic Alterations Related to Ag Production

Study Schedule

Task Completion Date

Finalize Model Geometry Oct-Nov 2013

Calibrate Models Nov - Dec 2013

Add Sediment Simulation Dec 2013

Run Model Scenarios Dec 2013

Summarize BMP Effectiveness (Sediment and Flow)

Apr 2013

Look at Nutrient Links ??????

Inform DSS 2014-15

Model Lake Nutrient Loads (Not Part of Scope)

???????