City of Prior Lake, MN
City of Prior Lake, MN

Lake Flooding Preparedness


City of Prior Lake
4646 Dakota St. SE
Prior Lake, MN 55372
   (952) 447-9800


Prior Lake Public Works
  (952) 447-9896
Scott County Dispatch
   (952) 445-1411


FEMA Floodplain Update
Flood Response Policy
Flood Protection Map
High Water No Wake Restrictions
Scott County Mitigation Plan
2016 Flood Mitigation Study

Flood at Watzl's

The National Weather Service provides accurate warnings and forecasts for Scott County and Prior Lake. If you observe a sudden rise in water or something unusual with a storm pond, creek, storm water drain, sanitary sewer manhole or street with flooding notify Prior Lake Public Works at (952) 447-9896 during regular business hours. Call Scott County dispatch at (952) 445-1411 after 4:30 p.m. or weekends.


Upper and Lower Prior Lakes have had great variation in the past, hitting highs of more than five feet above the average and sinking to more than 18 feet below average. The historic average lake level is a little lower than 902 ft., and the 100-year high flood event level is 908.9 ft. The 100-year flood level is the level of flood water expected to be equaled or exceeded every 100 years on average. The 100-year flood is more accurately referred to as the 1% flood, since it is a flood that has a 1% chance of being equaled or exceeded in any single year.

Body of Water Slow No Wake 100-Year Flood RFPE
Prior Lake 903.9 ft. 908.9 ft. 909.9 ft.
Spring Lake 912.8 ft. 914.4 ft. 915.4 ft.

The Regulatory Flood Protection Elevation (RFPE) refers to an elevation 1 foot (minimum) above the 100-year flood plus any stage increase due to the designation of flood fringe areas. In Prior Lake the flood plain regulations require that the elevation of the surface of the lowest floor of a dwelling be at or above the regulatory flood protection elevation. Local regulations will also require the top of the access road elevations to be within two feet of the flood protection elevation.

The Prior Lake City Code provides that the city manager will declare a slow no wake zone across all of Upper and Lower Prior Lake if lake levels exceed 903.9 ft. and will remain in effect until the lake has been below 903.9 ft. for three consecutive days. This provision reduces erosion created by wave action due to water craft operation.

In the event of flooding, residents of Prior Lake and Spring Lake shoreline can order sandbags, sand and sand delivery at the front desk at City Hall or by calling the front desk at (952) 447-9896. Residents are encouraged to utilize these services if they feel there is a need to protect their property. North Dakota State Univ. has developed a brochure on building strong effective sandbag walls for Fargo, ND that helps calculate the number of sandbags needed and how to anchor and reinforce the wall.

More information regarding floodplain management and shoreline alterations can be found online at The DNR has prepared the following handouts for shoreline restoration:
Beach Blanket
Shoreline Vegetation

The City takes weekly water samples at its two public beaches, Sand Point Beach and Watzl’s Beach. The samples are tested for E. coli bacteria in compliance with Minnesota Rule 7050.0222. High levels of E. coli can indicate the presence of harmful pathogens in the water.
Swimmer’s Itch Fact Sheet, U of M Extension:
E. coli information, MPCA
Beach Safety Website, MN Department of Health

FEMA publishes maps, called Flood Insurance Rate Maps (FIRMs), that show the areas in the community that have a 1 percent or greater chance of flooding in any given year, known as Special Flood Hazard Areas (SFHAs). FIRMs are the result of engineering studies that are performed by engineering companies, other federal agencies, or the community and are reviewed and approved by FEMA. The Community & Economic Development Department has copies of FIRMs for the City available for review. You may also obtain property flood information by calling the Community & Economic Development Department at (952) 447-9810. General flood information, including ordering of FIRM maps, is available on the FEMA website.

Letter of Letter of Map Revision Based on Fill (LOMR-F).
If you are a homeowner and believe your property is not located in the designated 100-year flood plain (also known as the Special Flood Hazard Area (SFHA)), as shown on the effective Flood Insurance Rate Map or Digital Flood Insurance Rate Map for Prior Lake and you would like FEMA to make an official determination regarding the location of your property relative to the SFHA, you may request a LOMA or a LOMR-F. For more information on how to apply for a LOMA or LOMR-R download the FEMA MT-1 Form.

Should you decide to evacuate please see the guidance for securing your home. If you need assistance in plugging your sewer please call the City at the numbers listed above. We also ask that you inform the city of your decision so that we are aware of the vacancy.

For general information about flooding visit the Homeland Security and Emergency Management website.