The Elm Creek TMDL (Total Maximum Daily Load) study addresses 22 impairments in the Elm Creek watershed and two impairments in the Crow River watershed that are on the 303(d) list located in the Upper Mississippi River Basin. Those in the Elm Creek watershed include nutrient impairments in Fish Lake, Rice Lake, Diamond Lake, Goose Lake, and Henry Lake; E. coli bacteria impairments in Rush Creek-South Fork, Rush Creek main stem, Diamond Creek, and Elm Creek; low dissolved oxygen impairments in Rush Creek main stem, Diamond Creek, and Elm Creek; and both fish and macroinvertebrate biotic integrity impairments for upper and lower reaches of the Rush Creek-South Fork, Rush Creek main stem, Diamond Creek, and Elm Creek. The TMDL also includes nutrient impairments in Cowley Lake and Sylvan Lake in the Crow River watershed. .
A Total Maximum Daily Load (TMDL) is a regulatory term in the U.S. Clean Water Act (CWA), describing a value of the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards.
Every two years, the Minnesota Pollution Control Agency (MPCA) releases the Federal Clean Water Act's (303d) list of impaired waters in Minnesota. Named after the section of the Clean Water Act in which the impaired waters law is found, the list includes all state lakes, rivers and streams known to exceed water quality standards.
A Total Maximum Daily Load (TMDL) and Implementation Plan must be prepared for each Impaired Water, identifying the contributors to the excessive loads of pollutants and outlining a plan for returning the water to an unimpaired state. Funding to undertake the TMDL studies is provided by grants from the MPCA.
Elm Creek Watershed-wide TMDL
Given the size and complexity of the Elm Creek system and the diversity of water quality impairments throughout watershed, a “phased” approach was used to develop the Elm Creek Watershed-wide TMDL. The most downstream section of Elm Creek (Rice Lake to the Mississippi River confluence) is currently listed for dissolved oxygen (DO) impairment. The upstream reaches and tributaries of Elm Creek (Rush and Diamond Creeks and Rice, Fish and Weaver Lakes) are all listed for a range of impairments (i.e., excessive nutrients, dissolved oxygen, biotic health and –potentially– bacteria).
Eventually, to comply with Minnesota water quality standards, each of these impairments will have to be individually addressed. However, because the upstream reaches and tributaries likely contribute to the DO impairment in lower Elm Creek and the DO impairment in upper Elm Creek likely contributes to related downstream impairments (e.g., nutrient impairment in Rice Lake), it is important to consider these systems as a whole.
The phased TMDL started by identifying the extent of the DO impairment in lower Elm Creek and the relative contribution to this impairment by upstream waterbodies. Specific impairments in upstream waterbodies were sequentially addressed to meet the water quality goals of each waterbody and those of the larger watershed. The final product of this phased project is a comprehensive TMDL that simultaneously addresses all the known impairments throughout the watershed.
Phase I of the TMDL began in Spring 2009 and extended through Fall 2010. The goal of Phase I was to characterize the Biochemical Oxygen Demand (BOD) loading to lower Elm Creek (Rice Lake to the Mississippi confluence).
Phase II was implemented in conjunction with Phase I and expanded current biological and chemical monitoring in priority sites throughout the Elm Creek watershed
Phase III began in Spring 2010 and continued through Fall 2013 . This phase developed TMDL projects for additional impaired waters in the Elm Creek watershed that simultaneously address DO impairment in Elm Creek (timing dependent on funding availability, level of impairment listing and potential for project leveraging). Those projects included development of excessive nutrient TMDL/implementation plans for Rice Lake, Fish Lake, Diamond Lake, French Lake, and Weaver Lake; development of an impaired biota TMDL/implementation plan for Rush Creek and Diamond Creek; and development of a bacteria TMDL/implementation plan for Elm Creek.
At 2012 year-end the monitoring phase of the watershed-wide TMDL was concluded and the technical consultants for the Commission had completed about 30% of the technical analysis and modeling. The Technical Advisory Committee, Modeling Committee and various stakeholder groups met to discuss modeling progress and key findings, provide updates, and receive feedback on various issues.
In 2012 the scope of the project was expanded through a contract amendment to include nine additional biotic impairments as well as expand the civic engagement component of the project.
The multi-stressor, watershed-wide TMDL and Implementation Plan was completed in 2016 and approved by the EPA on June 26, 2017.
Elm Creek WRAPS Report
The Clean Water Legacy Act (CLWA) requires that WRAPS reports:
summarize priority areas for targeting actions to improve water quality
identify point sources and identify nonpoint sources of pollution with sufficient specificity to prioritize and geographically locate watershed restoration and protection actions
include an implementation table of strategies and actions that are capable of cumulatively achieving needed pollution load reductions for point and nonpoint sources.
The Elm Creek WRAPS Report(Watershed Restoration and Protection Strategy) was submitted to the MPCA for their review on August 31, 2015. and approved on December 16, 2016.