The Aquatic Invasive Species (AIS) Prevention Plan & Rapid Response Plan for Scott County (2023-2024) was recently adopted by the PLSLWD Board of Managers. PLSLWD staff partnered with Scott County to be active participants in the creation and annual review of the County’s plans. This document, containing both the Prevention Plan and Rapid Response Plan, will continue to have annual review periods where the District will continue to be involved in the stakeholder review group.

Scott County AIS Prevention Plan & Rapid Response Plan 2023-2024

The Prevention Plan explains current initiatives in place to slow the spread of AIS such as boat inspections, aquatic plant treatments, and funding. The Rapid Response Plan explains the role of various stakeholders should a new AIS infestation occur in a Scott County lake. Establishing responsibilities and communication lines will help staff quickly mobilize monitoring and management strategies to reduce the infestation before it becomes unmanageable.

Purpose: To guide PLSLWD in the management of aquatic invasive species and, through education and awareness, prevention measures, and applied research, work with state and local partners to protect the District’s water resources from this environmental threat. These plans also help carry out objectives outlined in the District’s 10-year Water Resources Management Plan, such as:

• GOAL AIS1: Develop and implement an Aquatic Invasive Species (AIS) Response and Prevention Plan in coordination with Scott County to help prevent new AIS from entering District lakes, and
• GOAL AIS3: Monitor curly-leaf pondweed growth on Tier 1 lakes and treat as needed to prevent adverse effects on water quality

If you suspect a new infestation of an invasive plant or animal, take a photo and note the location, or save a specimen and report it to:

Contact April Londo (DNR), April. Londo@state.mn.us 651-259-5861

For more resources on Aquatic Invasive Species, visit the DNR Aquatic Invasive Species webpage.

According to the US Drought Monitor, the Prior Lake-Spring Lake Watershed District area is currently experiencing moderate drought. Possible impacts for this drought category include damage to crops and pastures, low water in lakes and streams, developing or imminent water shortages, and water use restrictions. Our local lakes, streams, ponds, and wetlands are all being impacted by the lack of precipitation.

Low water levels are not completely abnormal in the Prior Lake area.  The following graphs and images show fluctuations in water levels on Prior Lake since 1906.  Figure 1 displays the minimum lake level that was reported on each year there was data. Keep in mind, not all years have data and some years only have one reading, especially on years prior to 1970. The lowest level of 883.60’ was recorded in 1938, nearly 18’ lower than the lowest 2021 level of 901.34.

Figure 1: Prior Lake levels have been recorded since 1906.

Prior Lake in 2016: Elevation 902.5′

Prior Lake in 1937: Elevation 886.0′

Not only is the drought impacting water levels, but excessively hot temperatures are contributing towards algae growth and low dissolved oxygen levels, which can lead to fish kills.  Dead and dying fish have been observed recently on Little Prior and Lower Prior lakes.

Little Prior Lake Fish Kill on 7/29/2021

Low water levels and hot temperatures are believed to have contributed to this fish kill on Little Prior Lake observed on 7/29/2021.  Prior Lake-Spring Lake Watershed District staff reported dissolved oxygen (DO) levels ranging between 2.32 mg/l at the surface and 0.11 mg/l at the bottom of the lake that day.  Fish generally get stressed out when DO is lower than 4 mg/L, though different species have different tolerances.  Dead fish observed include panfish, largemouth bass, and northern pike.

To report fish kills, please call the state duty officer at 651-649-5451 and email the Prior Lake-Spring Lake Watershed District at info@plslwd.org