Lake Mauvaise Terre Watershed Implementation Plan

Synopsis

Located in central Illinois, Lake Mauvaise Terre is a backup water supply and a recreational resource for the City of Jacksonville. The lake is considered impaired for numerous constituents, including phosphorus and sediment. The city maintains a limited lake maintenance budget to conduct periodic dredging however annual and sediment and nutrient loads have impacted the longevity of these investments. Northwater was approached to help address watershed loading and secure outside funding to do so, beginning with the development of a comprehensive watershed plan.

Client(s):

American Farmland Trust, City of Jacksonville, IL
Services:

Water Resources, Water Supply
Market/Sector:

Agriculture, Government, NGO
Location:

Jacksonville, Illinois

Project Description

Lake Mauvaise Terre is located in Morgan County, Illinois and is a water supply for the City of Jacksonville. It is impaired for numerous constituents, including phosphorus and sediment. The project was unique and challenging due to its location, its lake pollution issues, and private land ownership. The AFT received a grant to conduct activities in the watershed aimed at reducing pollution loading to the lake. Northwater worked with AFT, the city and watershed stakeholders to model pollution loading, identify treatment practices and develop a Watershed Implementation Plan.

Roles included advanced GIS analysis and mapping, a custom map-based pollution load model, and the identified over 280 site-specific implementation projects. Expected pollution load reductions associated with recommended actions were calculated and practices were negotiated one-on-one with landowners. Northwater also performed a field assessment of watershed conditions, developed a monitoring plan and wrote a $700,000 Illinois EPA Section 319 grant application. To support the grant application, Northwater was able to secure a financial commitment from the city as well as each landowner; it encompassed over 200 projects with 12 landowners resulting in annual pollutant reductions to the lake totaling 1,773 tons of sediment, 4,131 lbs. of phosphorus, and 15,650 lbs. nitrogen.