About Peruque Creek and Lake St. Louis
The Peruque Creek watershed is located in parts of Warren and St. Charles counties in Missouri. Peruque Creek is a tributary to Lake St. Louis, and to the Mississippi River. This creek runs for 56 miles through various municipalities, including Foristell, Wentzville, Lake St. Louis, and O’Fallon, Missouri. Peruque Creek is not only a home to a variety of species, but it is also a place of recreation and enjoyment for many. People can look for fossils, go fishing, and swim along many parts of the creek. There are multiple public accesses to this creek at both city and county parks. Shortly after making its way through Wentzville, this creek becomes Lake St. Louis, a 625-acre lake where residents enjoy fishing and boating. The Peruque Creek and Lake St. Louis watershed provides an opportunity for families to get out into nature and make memories right in their very own backyard.
Unfortunately, both Lake St. Louis and Peruque Creek have been deemed impaired by the Missouri Department of Natural Resources (MoDNR) and the Environmental Protection Agency (EPA) due to pollution. Peruque Creek received its impaired status because of low dissolved oxygen levels and poor aquatic macroinvertebrate bioassessment results (meaning a low biodiversity of aquatic macroinvertebrates). Of the 21 miles of stream upstream of Lake St. Louis, 10 miles are currently impaired. Meanwhile, Lake St. Louis has been listed for high chlorophyll levels.
TMDL Reports & Updates
To tackle water pollution issues, MoDNR uses a tool called a Total Maximum Daily Load (TMDL). Essentially, a TMDL is a watershed planning tool that calculates exactly how much pollutant a water body can take while still meeting water quality standards, setting a clear goal for restoring our waters. While the lake and stream are listed for different reasons, sediment and nutrients have been deemed the primary target pollutants.
So, how do we actually meet TMDL goals? That is where our supplemental 9-element (9E) watershed management plan for Peruque Creek and Lake St. Louis comes in.
What exactly is a nine-element plan? It is a strategic framework required to unlock certain federal funding for stormwater and water quality-related projects. This 9E plan serves as a guide for achieving the TMDL's nonpoint source loading targets. It details voluntary approaches that those of us living in the watershed can use to help reduce pollution loading to our streams. It also maps out the crucial partnerships and funding sources we need to get these projects off the ground.
The Missouri Department Of Natural Resources accepted 9-Element Watershed Plan for the Lake St. Louis and Peruque Creek watershed is available at this link.
The Peruque Creek Watershed Alliance (PCWA)
The PCWA is designed to be a collaborative hub for residents, technical experts, and stakeholders working to improve water quality in the watershed. The Alliance serves as the “connective tissue” that brings these efforts together under one unified watershed strategy. Members of the Peruque Creek Watershed Alliance cooperatively use the 9-Element Watershed plan to guide initiatives across the watershed.
Our Mission
We work to improve and maintain water quality in the Peruque Creek and Lake St. Louis Watershed by promoting stewardship, advancing science-driven solutions, and fostering long-term sustainability. We engage the community through stakeholder collaboration, volunteer monitoring, education, and demonstration projects to protect, restore, and sustain the health of the watershed.
Our Team
City of Wentzville, PWSD #2, St. Charles County, City of Lake St. Louis, Lake St. Louis Community Association, General Motors, Wright Construction, St. Charles County Soil and Water Conservation District, Stream Teams United, Greenway Network, EDM Inc.
Looking to Get Involved?
Stream Team volunteers complete water quality monitoring seasonally at 14 different sites along the upper Peruque Creek. Our volunteers collect chemistry, biology and visual data. This information is integral to our mission of providing a window into the health of the watershed so we can understand its impairments and strategize how to make improvements.
Volunteers are also involved on Alliance committees, helping to guide initiatives across the watershed from multiple viewpoints, including interpreting water quality data, coordinating projects to improve water quality, working to receive and maintain funding for projects, and facilitating outreach opportunities within the community. These committees are tasked with interpreting water quality data, coordinating projects to improve water quality, coordinating and maintaining funding for projects, and facilitating outreach opportunities within our community.
Email us: [email protected] for more information or to find out how you can get involved!
Follow us on Instagram: @peruquecreekwatershedalliance
The Peruque Creek watershed is located in parts of Warren and St. Charles counties in Missouri. Peruque Creek is a tributary to Lake St. Louis, and to the Mississippi River. This creek runs for 56 miles through various municipalities, including Foristell, Wentzville, Lake St. Louis, and O’Fallon, Missouri. Peruque Creek is not only a home to a variety of species, but it is also a place of recreation and enjoyment for many. People can look for fossils, go fishing, and swim along many parts of the creek. There are multiple public accesses to this creek at both city and county parks. Shortly after making its way through Wentzville, this creek becomes Lake St. Louis, a 625-acre lake where residents enjoy fishing and boating. The Peruque Creek and Lake St. Louis watershed provides an opportunity for families to get out into nature and make memories right in their very own backyard.
Unfortunately, both Lake St. Louis and Peruque Creek have been deemed impaired by the Missouri Department of Natural Resources (MoDNR) and the Environmental Protection Agency (EPA) due to pollution. Peruque Creek received its impaired status because of low dissolved oxygen levels and poor aquatic macroinvertebrate bioassessment results (meaning a low biodiversity of aquatic macroinvertebrates). Of the 21 miles of stream upstream of Lake St. Louis, 10 miles are currently impaired. Meanwhile, Lake St. Louis has been listed for high chlorophyll levels.
TMDL Reports & Updates
To tackle water pollution issues, MoDNR uses a tool called a Total Maximum Daily Load (TMDL). Essentially, a TMDL is a watershed planning tool that calculates exactly how much pollutant a water body can take while still meeting water quality standards, setting a clear goal for restoring our waters. While the lake and stream are listed for different reasons, sediment and nutrients have been deemed the primary target pollutants.
- Peruque Creek TMDL: Addresses the aquatic macroinvertebrate impairment from Missouri’s 2022 List of Impaired Waters. The public comment period for Peruque Creek is now closed, but you can still view the drafted report online at dnr.mo.gov/public-notices-comments.
- Lake St. Louis TMDL: A TMDL is currently being drafted that will likely target nutrient loading. A public comment period for the lake's TMDL will open sometime later in 2026.
So, how do we actually meet TMDL goals? That is where our supplemental 9-element (9E) watershed management plan for Peruque Creek and Lake St. Louis comes in.
What exactly is a nine-element plan? It is a strategic framework required to unlock certain federal funding for stormwater and water quality-related projects. This 9E plan serves as a guide for achieving the TMDL's nonpoint source loading targets. It details voluntary approaches that those of us living in the watershed can use to help reduce pollution loading to our streams. It also maps out the crucial partnerships and funding sources we need to get these projects off the ground.
The Missouri Department Of Natural Resources accepted 9-Element Watershed Plan for the Lake St. Louis and Peruque Creek watershed is available at this link.
The Peruque Creek Watershed Alliance (PCWA)
The PCWA is designed to be a collaborative hub for residents, technical experts, and stakeholders working to improve water quality in the watershed. The Alliance serves as the “connective tissue” that brings these efforts together under one unified watershed strategy. Members of the Peruque Creek Watershed Alliance cooperatively use the 9-Element Watershed plan to guide initiatives across the watershed.
Our Mission
We work to improve and maintain water quality in the Peruque Creek and Lake St. Louis Watershed by promoting stewardship, advancing science-driven solutions, and fostering long-term sustainability. We engage the community through stakeholder collaboration, volunteer monitoring, education, and demonstration projects to protect, restore, and sustain the health of the watershed.
Our Team
City of Wentzville, PWSD #2, St. Charles County, City of Lake St. Louis, Lake St. Louis Community Association, General Motors, Wright Construction, St. Charles County Soil and Water Conservation District, Stream Teams United, Greenway Network, EDM Inc.
Looking to Get Involved?
Stream Team volunteers complete water quality monitoring seasonally at 14 different sites along the upper Peruque Creek. Our volunteers collect chemistry, biology and visual data. This information is integral to our mission of providing a window into the health of the watershed so we can understand its impairments and strategize how to make improvements.
Volunteers are also involved on Alliance committees, helping to guide initiatives across the watershed from multiple viewpoints, including interpreting water quality data, coordinating projects to improve water quality, working to receive and maintain funding for projects, and facilitating outreach opportunities within the community. These committees are tasked with interpreting water quality data, coordinating projects to improve water quality, coordinating and maintaining funding for projects, and facilitating outreach opportunities within our community.
Email us: [email protected] for more information or to find out how you can get involved!
Follow us on Instagram: @peruquecreekwatershedalliance
Peruque Creek watershed is a tributary to Lake St. Louis. See the watershed map and photos of Peruque Creek and Lake St. Louis below: