Prior Lake, Upper | Prior Lake Spring Lake Watershed District

Quick Facts

DNR Lake Number: 70007200
Surface Area: 386 acres
Average Depth: 10 feet
Maximum Depth: 43 feet
Bathymetry Map: View map here
Ordinary High Water Level: 903.9 feet above sea level
High Water No-Wake Restrictions: When lake level exceeds 903.9 feet*
Watershed Area: 16,038 acres
Impairment Status: Impaired for Mercury,** Biota,*** and Excess Nutrients****
Connectivity to other waterbodies: Water flows into Upper Prior from Spring Lake through the Spring Lake channel and flows Upper Prior into Lower Prior Lake.
Public Boat Access: Dewitt Ave (on southern end of Upper Prior)
Bridge Clearance: The elevation at the bottom of Wagon Bridge (bridge under Highway 21) is approximately 911.5′. Subtract the current lake elevation from 911.5′ to get the approximate clearance.
Aquatic Invasive Species: Zebra mussel, Eurasian watermilfoil, curlyleaf pondweed, common carp

*No-Wake restrictions are set by the City of Prior Lake and enforced by the Scott County Sheriff. Once high water levels have subsided and remained below the no-wake level (903.9 ft) for 72 hours, no-wake restrictions will be lifted. For more details, view the full city ordinance.

**Mercury impairments are not handled at the local government level. The State of MN has a TMDL they are following here.

***Biota impairments are not handled at the local government level. The State of MN addresses impaired biota by examining the interactions of numerous physical, chemical, and biological processes that define community composition. Biological impairments can be driven by natural or unnatural changes to one or many components of these systems. Biological impairments differ from some traditional water quality impairments in that the impaired biotic communities are indicators of disturbance rather than causes of disturbance. Biological impairments are commonly caused by stressors that are not considered conventional pollutants. These include stressors such as degraded habitat or altered hydrology. Minnesota utilizes the process of stressor identification developed by the EPA to identify the dominant stressors.
****See the TMDL study for more information.

Lake Levels

All lake level data below are approximate and preliminary – NOT to be used for legal purposes. Sudden drops or spikes are often due to calibration, which are manual adjustments to correct the lake level value. Please contact the PLSLWD office for official readings.

For more information about the Outlet Structure, click here.

Occasionally, especially during cloudy weather, the level logger does not get service and the lake level does not get updated automatically on the graph below. This can last for a couple days and there is nothing we can do. If you need to know the lake level, you can check the staff gauge on the NW pillar of Wagon Bridge (Hwy 21 bridge crossing Prior Lake, across the road from Knotty Oar Marina). Just add 900 to the number that you see to get the mean sea elevation.

Historical Lake Levels

The graph below displays the average of annual lake level readings, when available. Some years only had one lake level measurement so those would not reflect the “average” and could have been taken at any time of year. Also, some years are missing from this graph because there is no known data available. The red line indicates when the weir was installed. Prior to the red line, there was no natural outlet for Prior Lake.