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Water Resources
This Web page features information about the City of Prior Lake's water resources and highlights inportant information every resident should know
regarding how to protect it. Water quality and conservation, lakeshore preservation and our lakes' varying levels are all important factors that play a role in the quality of life enjoyed by each resident.
We are all responsible for the health of our water resources, not just for our own use, but for the wildlife ecosystems that rely on it. Whether through direct use of the City's water or through the runoff from our yards and streets, pollutants find their way into the water and degrade this valued resource.
| LAKE WATER QUALITY |
The many lakes in the City of Prior Lake are ultimately affected by what happens on the land draining to them. Often water quality is taken to mean water clarity; however, a broad range of nutrients and pollutants go into the water quality equation.
Lake over-fertility: In the same way homeowners and farmers alike fertilize their lawns and fields to create a lush green lawn or plentiful crops, fertility in ponds and lakes cause similar effects: algae blooms and floating mats of vegetation. Because green is not the color we want in our lakes, we all need to reduce the amount of fertility the water receives. Efforts include sweeping dirt and leaves from streets, preventing and controlling soil erosion and monitoring construction site erosion.
Some simple things that combat over-fertility
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| Compost lawn clippings, leaves, and pet waste, never allow them to wash from the street into the drain. |
| Get your lawn tested before fertilizing. Mail-in soil tests are available at the University of Minnesota Soil Testing Laboratory. Click here to use this soil sample information sheet. |
| Use lawn fertilizers sparingly, and only when a soil test recommends it, and never used banned phosphorus fertilizers. |
| Leave a buffer of natural vegetation between your manicured lawn and nearby surface water. |
| For more simple things you can do, visit the
Metro WaterShed Partners Website. |
Other pollutants: In addition to over fertility, water quality can be affected by bacteria, chlorides, petroleum, and a variety of toxic chemicals.
Some simple things that combat other pollutants |
| Never dump household chemicals or motor oil down the drain or onto land. |
| Report illicit dumping of trash or chemicals to the City. |
| Keep your automobile well tuned and leak free. |
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| LAKESHORE PRESERVATION |
Beach erosion is a constant issue for homeowners near lakes. Varying water levels, wave energy, improperly constructed retaining walls, steep slopes, ice action and mowing to the water's edge can all contribute to shoreline erosion.
For home owners looking to address shoreline erosion, there are a variety of resources for design assistance as well as requirements to consider prior to construction. The DNR has extensive information about erosion issues in which requirements are detailed. A quick place to start is at this DNR Web page on shoreline alterations.
For more detailed information, the DNR Publication “Lakescaping for Wildlife and Water Quality” or the instructional CD-ROM “Restore Your Shore” can be purchased from the Minnesota Bookstore.
Grant opportunities are available for homeowners through the Prior Lake Spring Lake Watershed District for natural shoreland restoration.
Before proceeding with construction, contact the City of Prior Lake and Minnesota DNR to make sure you have all the appropriate permits. Improper construction can lead to legal action and a restoration order by the City or State. |
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. At average levels, Lower Prior Lake is 925 acres and Upper Prior Lake is 415 acres (Spring Lake is 600 acres). Tabulated below are some of the water marks.
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Level (feet) |
Event |
+6.94 |
1% probability modeled flood
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+5.64 |
Highest recorded water without outlet
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+3.72 |
Recent high water with outlet
(Summer '83)
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Ordinary high water level
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+0.54 |
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Average water elevation
(901.96 feet above sea level)
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-5.96 |
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-6.5 |
Recent low water with outlet
(Spring '90)
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-18.35 |
Lowest recorded water level
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Notable events in recent history include the 1930s draught known as the Dustbowl. Lake levels during this period hit more than 18 feet below average, separating Upper and Lower Prior Lakes into five separate bodies of water. Farmers reportedly bailed hay off the lake bottom. In 1990, as water levels sank six feet below average, residents considered even the most impractical measures of pumping river or groundwater to  refill the lake.
Since 1992, Prior Lake residents have been fortunate to have the lake only vary in a historically narrow three-foot range; however, even this amount of variation can cause problems.
Lakes level control: The Prior Lake Spring Lake Watershed District operates and maintains
| An aerial view of Upper and Lower Prior Lake during the 1930s Dustbowl. |
and outlet on Lower Prior Lake. The outlet is fixed at 902.5 feet above sea level and provides some safety from extreme flood events, however; there is no effort to further regulate the level. Depending on the amounts of rain and snowfall, the intensity of heat, wind and evaporation, and groundwater interaction, the levels of the lakes fluctuate and are allowed to vary following their natural cycle, as this graph of Lake Levels From 1970 shows.
The outlet, while providing some level of safety during a flood, does not prevent all risk. Only three years after the outlet was constructed, record precipitation caused lake levels to rise more than 1.5 feet above the ordinary high water level, flooding many homes.
When water levels go down, there is no reliable method to add water to the Lake. Periods of prolonged drought can cause the lake level to fall dramatically. From the autumn of '86 to the autumn of '89 water levels in Prior Lake fell seven feet.
For more information:
The most recent water level information is available through the Prior Lake Spring Lake Watershed District.
Direct any water-quality questions to Water Resources Engineer Ross Bintner at (952)447-9831, rbintner@cityofpriorlake.com, or attend the Lake Advisory Committee meeting at City Hall. Times and Dates are available in the homepage calendar.
| DOWNLOADS |
| Handouts, applications and forms can be downloaded by clicking on the links below. More information can be found in the Document Center, under "Forms, Apps & Handouts." |
To access data on any of the Lakes in the City, search by lake name on the DNR “Lake Finder” site.
Up-to-date weather forecasting is available through the National Weather Service.
The Prior Lake Spring Lake Watershed District owns the Prior Lake outlet structure and outlet channel.
The North American Lake Management Society provides information
on the management and protection of lakes and reservoirs.
The Center for Watershed Protection provides broad-based and technical watershed strategies for natural resource protection.
The EPA provides the following documents that discuss some of the effects of storm water run-off and solutions to this pollution source:
> After the Storm
> Make Your Home the Solution to Stormwater Pollution Brochure
> Water Efficient Landscaping
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