Floodplain Permits Along Highway 94: What Owners Need

If you own property along Highway 94, you live close to some of St. Charles County’s most beautiful river corridors. You also live where floodplain rules matter. With the right plan, your project can move forward safely and support your long-term property value.

Why Floodplain Permits Matter Before Projects

Floodplain permitting protects people, structures, and the natural flow of water. St. Charles County participates in the National Flood Insurance Program, which requires permits for development inside mapped flood zones so the county stays eligible for flood insurance and disaster aid according to the county. More than 40 percent of the county is flood-prone, and many parcels along Highway 94 lie within regulated areas where permits apply per county guidance. FEMA also requires communities to issue permits before construction in Special Flood Hazard Areas so NFIP standards are enforced per FEMA.

When you follow the process, you reduce risk, protect eligibility for insurance and financing, and keep your options open for future resale.

Confirm Your Floodplain Status

Before you sketch plans or hire a contractor, confirm if your project touches a regulated floodplain, floodway, or watercourse.

Use Official Maps and Surveys

• Pull the FEMA Flood Insurance Rate Map for your address using the FEMA Map Service Center. This helps you confirm the flood zone and the base flood elevation that applies to your site FEMA Map Service Center.
• Ask a licensed surveyor to verify your site’s benchmark elevations if you plan new construction or substantial improvements. St. Charles County requires the lowest finished floor of new or substantially improved structures to be at least 1 foot above base flood elevation, documented by an Elevation Certificate per county rules.

Gather Existing Property Documents

• Prior surveys or plats
• Elevation Certificates
• Past building and floodplain permits
• Site plans, grading plans, and any drainage studies

Having these ready speeds up reviews for floodplain, land disturbance, and building permits see county submittal guidance.

Clarify Project Area and Scope

• Sketch the footprint of the work, access routes, and material staging areas.
• Note any work near streams, ditches, or culverts.
• Identify if any portion may enter state right of way along Highway 94, which would require a separate MoDOT permit per MoDOT.

What Projects Need Permits

Floodplain rules apply to much more than new houses. Even small changes can affect flood flows and compliance.

New Construction and Additions

• New homes, garages, and additions inside Special Flood Hazard Areas require a Floodplain Development Permit. Elevation and design must meet county freeboard and floodproofing standards per county floodplain permit page.
• Substantial improvements to existing structures, defined by the county as 50 percent or more of market value, trigger updated elevation and documentation requirements county definition and requirements.

Grading, Fill, and Driveways

• Any grading, fill, excavation, or bank work in a mapped floodplain can require a Floodplain Development Permit and often a Land Disturbance Permit for areas 5,000 square feet or more per county rules.
• Driveway and culvert modifications that affect the highway or its drainage require MoDOT approval if inside state right of way. Expect engineered drawings and traffic control plans for safety and drainage protection MoDOT permits.

Utilities, Fences, and Accessory Structures

• Utility lines, sheds, fencing, and similar features may require a floodplain permit if they are inside regulated areas. Some items that normally do not need a building permit still need floodplain review when placed in a flood zone per county.

Repairs and Post‑Flood Work

• After a flood, repairs can cross into substantial improvement depending on scope and cost. Confirm with the county whether your project meets routine repair thresholds or requires a Floodplain Development Permit and an Elevation Certificate county guidance.

How the Permit Process Works

A clear roadmap keeps your project on track and avoids rework.

Pre‑Application Research and Outreach

• Verify your flood zone using FEMA maps and gather your records FEMA MSC.
• Call St. Charles County Planning and Development to discuss your parcel, jurisdiction, and permit triggers. If the property lies inside a city, the municipality may have its own rules and permits too example city resource.
• If work touches streams or wetlands, request a pre‑application consult with the U.S. Army Corps of Engineers St. Louis District to determine if a federal permit is needed USACE Regulatory. If USACE jurisdiction applies, MDNR Section 401 Water Quality Certification often runs in parallel MDNR 401.

Application Materials and Plans

Typical submittals include:

• Floodplain Development Permit application via the county portal county permit page
• Site plan and grading plan with contours, drainage, and erosion controls for land disturbance county land disturbance rules
• Sealed building plans and an Elevation Certificate for new or substantially improved structures showing at least 1 foot of freeboard above base flood elevation county substantial improvement guidance
• If encroaching in a FEMA floodway, a hydrologic and hydraulic analysis and a No‑Rise certification are typically required by ordinance ordinance reference
• For work in state right of way, a MoDOT encroachment permit with traffic control and, if needed, hydraulic calculations MoDOT permits
• For impacts to waters, USACE permit forms and any MDNR 401 materials USACE and MDNR

Reviews, Conditions, and Approvals

• County plan review for common building permits is often targeted at roughly 10 working days, while floodplain and multi‑agency projects can take longer based on complexity county plan review timing.
• MDNR 401 certifications typically review in about 60 days once an application is complete MDNR timeline.
• USACE timelines vary by permit type. Nationwide Permits can be faster than Individual Permits, which may include public notice and alternatives analysis USACE overview.
• Expect conditions of approval such as erosion controls, elevation benchmarks, and inspection stages.

Inspections and Final Closeout

• The county will inspect as work proceeds. Keep your elevation benchmarks visible and schedule key inspections promptly.
• Retain final documents: approvals, inspection reports, Elevation Certificates, and any No‑Rise certifications. These will support insurance, lending, and future resale NFIP compliance context.

Costs, Timing, and Common Pitfalls

Incomplete or Inaccurate Submittals

Missing sheets, wrong elevations, or unsigned certificates often cause delays. Use qualified professionals and double‑check plans against the county’s requirements for floodplain and land disturbance county requirements.

Starting Work Before Approval

Starting early can lead to stop‑work orders and penalties. County ordinance includes administrative penalties when work occurs without a Floodplain Development Permit, and larger enforcement actions are possible for repeated violations ordinance penalties. FEMA also ties community compliance to NFIP eligibility, which supports affordable flood insurance for owners FEMA overview.

Scope Changes Mid‑Process

If the footprint, fill quantity, or access route changes, notify reviewers. New impacts can trigger re‑review or additional agencies, such as MoDOT if you enter the right of way MoDOT or USACE if you expand into waters USACE.

Seasonal and Access Constraints

River levels, saturated soils, and limited shoulder access along Highway 94 can slow work. Plan staging and traffic control ahead of time and build weather buffers into your schedule.

Insurance, Financing, and Resale Impacts

Insurance and Lender Considerations

Lenders require flood insurance for properties in Special Flood Hazard Areas. Verified compliance and accurate Elevation Certificates can influence coverage and premiums. Properties with unpermitted work risk NFIP issues, including potential declarations that limit insurance until violations are corrected NFIP context.

Appraisals and Marketability

Buyers and appraisers look for clear, compliant files. Elevation data, permits, and final approvals signal lower risk, support valuation, and help buyers feel confident about ongoing costs and insurability.

Disclosures and Document Retention

Keep a clean record:

• Permit applications and approvals
• Inspection logs and photos
• Elevation Certificates and No‑Rise letters
• Any USACE, MDNR, or MoDOT permits

Organized documentation simplifies disclosure and due diligence for future sales.

Plan Your Next Steps With Confidence

Here is a simple path:

1. Confirm your flood zone using FEMA maps and past surveys.
2. Define the scope and identify where it touches floodplain, watercourses, or right of way.
3. Coordinate early with the county and other agencies as needed.
4. Submit complete plans and track reviews.
5. Document inspections and keep final approvals for your records.

If you are weighing improvements or preparing to sell a Highway 94 property, we can help you time the steps and prepare a clean file that supports insurance, lender, and buyer expectations. Request a Complimentary Consultation with Susan Hurley Homes for tailored guidance on due diligence, project sequencing, and pre‑listing strategy.

FAQs

Do I need a floodplain permit for small projects like fences or sheds?

• Possibly. In regulated flood zones, even small items can require a Floodplain Development Permit. Check with the county before starting work county floodplain permit.

How high must I build if my home is in the floodplain?

• For new or substantially improved structures, the county requires the lowest finished floor to be at least 1 foot above base flood elevation, documented by an Elevation Certificate county requirements.

What if my project is near Highway 94 right of way?

• Any work in or affecting state right of way needs a MoDOT permit. Driveway changes, culverts, or shoulder work require submittals and may need engineered plans MoDOT permits.

When do USACE and MDNR get involved?

• If you place fill in wetlands or streams or impact waters of the U.S., USACE authorization may be required. When USACE permits apply, MDNR Section 401 Water Quality Certification often runs in parallel USACE and MDNR.

How long will reviews take?

• County plan review for common permits often targets about 10 working days, but multi‑agency floodplain projects can take longer. MDNR 401 reviews typically run about 60 days once complete. USACE timelines vary by permit type county timing and MDNR 401.

What are the consequences of starting work without a permit?

• You risk stop‑work orders, administrative penalties, and delays. County ordinance outlines fines for working without a Floodplain Development Permit, and unpermitted work can also affect insurance eligibility ordinance penalties and NFIP guidance.

Where can I find official forms and guidance?

• Start with the county’s floodplain permit page and land disturbance resources, FEMA’s mapping portal, and state and federal program pages. Missouri SEMA also hosts model forms, including No‑Rise and elevation templates county floodplain, FEMA MSC, and SEMA forms.