# Land Disturbance Permits and Stormwater Requirements for Site Work in the St. Louis Metro > Disturbing 1+ acre in Missouri needs DNR stormwater permit coverage and a SWPPP, plus local permits from MSD, St. Louis County or St. Charles County. Canonical: https://kueselinc.com/blog/land-disturbance-permit-stormwater-requirements-st-louis Last updated: 2026-10-27 Published October 27, 2026 · 5 min read · By Kuesel Excavating In Missouri, construction that disturbs one acre or more, or less than an acre when it is part of a larger common plan of development, needs coverage under the Missouri Department of Natural Resources (DNR) land disturbance stormwater permit, along with a stormwater pollution prevention plan (SWPPP). In the St. Louis metro you also need local approvals, which can include St. Louis County or municipal land disturbance permits, MSD review in St. Louis City and most of St. Louis County, and a St. Charles County land disturbance permit for sites of 5,000 square feet or more in its jurisdiction. This post is a general overview for developers, GCs and owners. Rules change and every site is different, so confirm the current requirements with each agency and your civil engineer before you mobilize. ## When do you need a Missouri DNR land disturbance permit? According to Missouri DNR, land disturbance permits are required for construction activities that disturb one or more acres. Sites under one acre also need coverage when they are part of a larger common plan of development or sale that will disturb one acre or more in total over the life of the project. Most commercial and industrial projects are covered under DNR's general permit for construction or land disturbance (the MORA permit, with site-specific permits numbered MO-RAxxxxx). Key points from DNR: - Applications are filed online through DNR's ePermitting system; DNR no longer processes paper MO-RAxxxxx applications - You must register through the Missouri Gateway for Environmental Management (MoGEM) before using ePermitting - Permit fees are tiered by acres disturbed and are listed on DNR's construction land disturbance page - DNR states that the current general permit expires Feb. 7, 2027, and it is being renewed; check DNR's page for renewal instructions before you apply or renew DNR also offers an area-wide land disturbance permit, but it applies only to cities, counties and other government agencies with an approved stormwater program, not to private developers. ## What does the SWPPP have to include? The MORA permit requires the permittee to develop and implement a SWPPP with site-specific best management practices (BMPs) that limit soil exposure, erosion and pollutant discharge. DNR's summary of the permit says: - The SWPPP must be kept on site, in paper or electronic form, and provided to DNR within 24 hours of a request - It must include an inspection schedule, and each inspection must be logged with a written report - Site inspections are required at least monthly - BMP or stabilization deficiencies must be documented and corrected as soon as possible, and no more than 7 calendar days after the inspection - The SWPPP must be reviewed at least once a year, and more often when site conditions change Read the full permit for stabilization and termination requirements. Local permits often add their own inspection and maintenance conditions on top of DNR's. ## What does MSD require in St. Louis City and St. Louis County? The Metropolitan St. Louis Sewer District (MSD) serves the City of St. Louis and most of St. Louis County. MSD states that all public or private sewer and drainage work proposed within its boundaries, including any change to a storm drainage channel, site drainage or floodplain, requires MSD review and approval. Plans are submitted through MSD's online plan review and permitting system and must be prepared and sealed by an engineer registered in Missouri. MSD posts its current fees online. Projects must meet MSD's Rules and Regulations and Engineering Design Requirements for sanitary and stormwater facilities. MSD has published draft 2027 rules: plans first submitted before January 1, 2027 fall under the 2018 rules, and plans submitted on or after that date fall under the 2027 rules. If your project is in design now, ask your civil engineer which set applies. After construction, MSD's rules require an annual maintenance report for stormwater BMPs, and property owners and HOAs are responsible for maintaining their detention basins. That is where bioretention and bio-pond maintenance becomes an ongoing owner cost. ## What does St. Louis County require? St. Louis County's Land Disturbance Code (Chapter 1114) applies in unincorporated areas and in municipalities that contract with the County for enforcement. It uses a major permit for projects of one acre or more and an ordinary permit for smaller sites, with a narrow exemption for very small improvements. The code also notes that a DNR permit is required where one acre or more will be disturbed. Many municipalities in the county have their own grading and land disturbance rules, so check with the city where the site is located. ## What does St. Charles County require? St. Charles County's Unified Development Ordinance (Chapter 412, Erosion and Sediment Control Regulations) makes it unlawful for an owner or the owner's agent to perform land disturbance affecting 5,000 square feet or more without a land disturbance permit, subject to listed exemptions. Cities in St. Charles County, such as O'Fallon, St. Peters and Wentzville, administer their own requirements inside their limits, so confirm the jurisdiction first. ## How can the site contractor help with permitting? The owner and civil engineer typically prepare the permit applications and SWPPP. The site contractor builds and maintains the controls. A contractor who has worked under these permits can help by: - Reviewing the erosion control phasing during preconstruction so it can actually be built - Installing perimeter controls and construction entrances before mass grading - Keeping sediment basins and inlet protection working as grades change - Fixing deficiencies found during inspections promptly - Building permanent detention and water-quality BMPs to the approved plans Kuesel is an MSD vendor and builds MSD stormwater BMPs, including bioretention basins, and maintains bio-ponds for owners. ## Land disturbance permit FAQ ### Does a half-acre project need a DNR permit? Usually not on its own, but it does if it is part of a larger common plan of development that disturbs one acre or more. Local permits may still apply. ### Who is responsible for the SWPPP? The permittee, typically the owner or developer, though the contractor's field work carries out much of it. Spell out responsibilities in the contract. ## Request a bid on your St. Louis site Send your civil plans and SWPPP through our bid invite and Kuesel's estimators will respond within one business day. Call (636) 978-3478, Monday through Friday, 7am to 4pm. ## Related - [Municipalities & MSD work](https://kueselinc.com/msd) - [Bioretention basins](https://kueselinc.com/bioretention-basins) - [Bio pond & basin repair](https://kueselinc.com/bio-pond-maintenance) - [Invite us to bid](https://kueselinc.com/bid-invite) - [Blog](https://kueselinc.com/blog) - [Request a bid](https://kueselinc.com/contact) - [Invite us to bid](https://kueselinc.com/bid-invite) - [Services](https://kueselinc.com/services) - [Projects](https://kueselinc.com/projects)