Flooding in Cascade County

Floodwaters can cover much of the county and are very dangerous. Even though floods may appear to move slowly (3 feet per second), a flood two feet deep can knock a man off his feet and float a car. Your property may be high enough that it has not flooded in the past. However, it can still be at risk for future flooding. Contact the County Floodplain Administrator at 406-454-6905 to determine if your property is in a floodplain.

If you live in a floodplain, you have a 26% chance of being flooded during a 30-year mortgage period. Compare this to your 4% chance of fire during that same period.

You don’t need to live near water to be flooded. Just an inch of water can cause costly damage to your property.

Historical Flood Events in Cascade County’s History

Flood events have occurred throughout Cascade County’s history periodically, according to the FEMA Flood Insurance Study, flood events occurred in 1894, 1899, 1908, 1916, 1927, 1936, 1948, 1953, 1958, 1964, 1965, 1966, 1969, 1975, 2011, and 2018. 

Cascade County is commonly swept by high westerly winds called “chinooks”.  These winds can create rapid snow melt events in March or April and can cause flooding while the ground is still frozen.  Flood events have also occurred due to heavy snowmelt in May and June, or high-intensity rainstorms later in the summer.  Among the areas regulated through the Cascade County Floodplain Regulations are the Sun and Missouri River Basins and the Belt and Sand Coulee Creeks.

Outreach Completed by Cascade County’s Floodplain Administrator

Cascade County makes a concerted effort to reach out to County residents concerning the threat posed by flooding.  The Floodplain Administrator’s office keeps all of FEMA’s Flood Insurance Rate Maps, recorded Elevation Certificates and Letters of Map Amendments, and numerous other Flood related information.  The County specifically reaches out to realtors, insurance agents, and lenders with newspaper ads.  The most recent newspaper ad was in the Great Falls Tribune on April 1, 2018.

Stream Gauge Information for FEMA Regulated Streams or Rivers in Cascade County

The United States Geological Survey places information from various stream gauges on their website.  Or the following links can be used for specific sites:

FEMA National Flood Hazard Layer

Flood Protection Library

Floodplain material, including maps, brochures, and books are available online, within the Planning Office and within the Great Falls Public Library.  Some examples of these materials include:

Various pictures, articles, and other material documenting historic flooding of Cascade County.  We offer books published by FEMA and the National Flood Insurance Program to assist residents about how to construct new structures or retrofit existing structures within the regulated floodplain.

Protecting your property from flooding can involve a variety of actions, from inspecting and maintaining the building to installing protective devices. Those that affect the structure of your building or their utility systems are provided by the FEMA Resources and Documents.

The publication linked with this headline shows how flood-prone houses in south Florida were elevated above the 100-year flood level following Hurricane Andrew. Alternative elevation techniques are also demonstrated.

The publication linked with this headline is intended to acquaint the public with the National Flood Insurance Program (NFIP). Despite the highly technical nature of the Program, there has been a deliberate effort to minimize the use of technical terms. This publication is designed for readers who do not need a detailed history or refined technical or legal explanations, but do need a basic understanding of the program and the answers to some frequently asked questions. Readers who need legal definitions should refer to the Standard Flood Insurance Policy and to NFIP and related regulations.

Flooding in residential areas is bound to happen in flood-prone areas resulting in property damage. The manual linked with this headline is for designers, developers, builders, and others who wish to build elevated residential structures in flood-prone areas.

The publication linked with this headline reflects the requirements of the most current codes and standards and provides a best practices approach in reducing damages from natural hazards. This document concentrates on flood and wind events while also addressing seismic hazards, and recommends several multi-hazard resistant foundation designs. Designs are included for wood-framed foundations, conventional concrete and masonry pier foundations, and ground anchors. The ground anchor foundations are based on results from a series of first-of-its-kind saturated and dry soil anchor tests.

The guidebook linked with this headline has been written to introduce officials and citizens at the local level to a basic understanding of natural resources in floodplains and to offer suggestions for creating strategies for wisely managing these important areas. As scientific understanding of ecosystems grows, the importance of conserving and restoring the natural resources and functions of floodplains is increasingly recognized. Historically, effective floodplain management was recognized as a necessary task to reduce the loss of life and property. However, floodplain areas are now also recognized as having an intrinsic value of their own as a part of the interconnected ecosystem and an influential role in increasing a community's quality of life.

The publication linked with this headline is intended to help local offices in cities, towns, villages, and counties in the United States understand what they can do to reduce the damage, disruption, and public and private costs that result from the shallow, localized flooding that occurs within their jurisdictions. This is flooding that all too often escapes the attention received by larger floods or those that are clearly mapped and subject to floodplain development regulations.

Floodplain Permit Application

Floodplain Permit fees for Cascade County are $250 per County Resolution 13-19. Fees are set by the County Commission and due upon application.

The following are examples of projects that would require an Approved Floodplain Permit:

Flood Insurance

Because no retrofitting measure is foolproof, especially against higher, less frequent floods, flood insurance is recommended. If you don't have flood insurance, talk to your insurance agent.

What can you do to help prevent flooding?

Several of the County’s efforts depend on your cooperation and assistance. Here is how you can help: