Q&A and FAQs

A biotic survey was conducted in 2022 to identify what and where invasive species exist in and around Penn. Management will depend on the type and amount of each species. For example, carp management will be included in the plan’s fisheries interventions and invasive plants, like purple loosestrife, will be addressed in the plan’s wetland interventions.

Yes. The aerator will continue operation as it has in years past. Currently the City is working to upgrade the aerator's pump. In the future new upgrades may occur as the City progress in their lake management projects. The old groundwater was well that used to augment lake levels will be removed. The well removal is associated with the Penn Lake Wellhead Protection Initiative (PLWPI).

There are fish in both Upper and Lower Penn Lake. Some of them are native, such as green sunfish, largemouth bass, fathead minnows and black bullhead. Unfortunately, the most common fish in Penn are invasive. They include common carp, goldfish, and carp-goldfish hybrids.

While the City of Bloomington is committed to going above and beyond in our efforts to improve the health of Penn Lake, there are certain legal management requirements that we are bound to pursue. These requirements are set by the Minnesota Pollution Control Agency (MPCA) and are tied to the Federal Clean Water Act. The MPCA has designated Penn Lake as impaired under a total daily maximum load threshold. Basically, that means too many nutrients are washed into Penn Lake. Because of this, the City is required to reduce the amount of nutrients that reach the lake. Therefore, the Penn Lake Management Framework is required to prioritize stormwater management. Fortunately, improving stormwater management in Penn’s watershed will benefit many in-lake characteristics and other management goals!

In the 1970s a groundwater well was installed on the north end of Lower Penn Lake. The well was used in an attempt to manipulate Penn Lake water levels. For it to even come close to having an impact on water levels, the well had to pump hundreds of millions of gallons of groundwater. Because use of groundwater for lake level management is environmentally harmful and unsustainable, the DNR now limits the amount of water these sorts of augmentation wells can pump to ten million gallons a year – a tiny fraction of what is needed to impact Penn’s water levels. As such, the well has not been used for over a decade. All wells pose a significant risk to groundwater resources. If a pollutant gets into the pipe, it can immediately contaminate the area’s groundwater. The well is also old and falling into disrepair. As described in the City’s PLWPI, the City is committed to protecting groundwater resources around Penn Lake and will be removing the well in either late 2023 or early 2024. Please contact the City’s water resources staff for more information.