Hiawatha Golf Course Property Master Plan Update: Groundwater PumpingPosted on 20 December, 2019
At its last meeting, the Hiawatha Golf Course Property Master Plan Community Advisory Committee (CAC) asked Minneapolis Park and Recreation Board (MPRB) staff and consultants to explain why and when groundwater pumping at the golf course is bad and why the MPRB wants to reduce pumping.
Below is an explanation of how efforts to keep the golf course dry negatively affect the property’s natural environment and its ability to recover from flooding and increased precipitation.
First, a few facts about the Hiawatha Golf Course Property:
- The property is situated adjacent to and below the normal elevation of Lake Hiawatha.
- Two pieces of infrastructure keep the course dry: a large berm (raised bank) that separates Lake Hiawatha from the golf course, and six water pumps that remove water from wet areas and pump it into the lake.
- Dewatering coincidentally creates a cone of depression that protects, to some degree, nearby homes’ basements from groundwater intrusion.
- The MPRB has a new permit from the Minnesota Department of Natural Resources (DNR) to pump up to 308 million gallons of groundwater from the property annually, based on monitoring performed as part of a 2017 study.
- However, with an increasingly wet climate, the amount actually pumped has increased, estimated at more than 400 million gallons per year.
Efforts to maintain the property as an active recreation facility have the following negative effects on the natural environment and its ability to recover from large amounts of precipitation responsibly:
The berm separating the Lake Hiawatha from the Hiawatha Golf Course cuts off Minnehaha Creek and Lake Hiawatha’s use of the full floodplain during smaller, more frequent weather events.
The berm that separates Lake Hiawatha from the golf course cuts off the natural floodplain area, which limits the floodplain’s effectiveness during smaller, more frequent events along Minnehaha Creek. When rain falls over the watershed, the golf course area behind the berm cannot be utilized as floodplain storage.
Without the berm, these flows could be temporarily stored in a larger contiguous surface area of Lake Hiawatha and the golf course area, resulting in less bounce or swelling during non-catastrophic storms and potentially reducing creek levels upstream and downstream.
Reducing bounce on the creek and lake during these events could, for instance, allow the Lake Nokomis outlet to be open more frequently and sooner after rain events for relief of that lake. Floodplains are essential to the watershed; they are buffers that store extra water that falls over the watershed. Cutting off the floodplain is not responsible water management — it pushes water onto other properties upstream and downstream of Lake Hiawatha.
The berm does not allow floodwater to recede after a catastrophic event. Instead floodwater must be pumped from the golf course.
When the property catastrophically floods and the lake and creek overtop the berm, as it did in June 2014, floodwater becomes trapped behind the berm and can’t drain naturally. Instead, it must be pumped out, and that can only occur after the creek and lake draw down below the top of the berm.
In 2014, it took two weeks for floodwater to start to recede and more time to pump the water out. The course’s front nine holes reopened that fall and the full course reopened the following spring. Floodwater sitting on the course for a long period of time caused turf grass loss, tree loss, damage to irrigation components, and most importantly, a loss in revenue. In 2014, Hiawatha Golf Course lost more than $600,000 in net income in part due to flood damage and the loss of playable days. These are real costs that make the golf course unsustainable as a business operation within the MPRB’s Enterprise Fund.
Minnesota’s climate is getting wetter. Large, intense weather events are becoming more frequent, increasing the risk of flooding at the golf course.
According to the Minnesota State Climatology Office, precipitation is increasing in intensity and frequency in Minnesota. As our local climate gets wetter, the risk of flooding at the golf course increases. Regional groundwater modeling, updated recently to reflect current climate data, showed the increase in precipitation also results in higher recharge rates to groundwater. This causes elevated groundwater levels throughout the metro.
The Hiawatha Golf Course Property, which pumps shallow regional groundwater, stormwater runoff, and seepage from the lake, must pump more than ever, even outside of intense single rain events. Approximately 35 acres of the property lie below the ordinary high water level of Lake Hiawatha, putting the property in a vulnerable condition that relies entirely on the berm and significant pumping to maintain soggy conditions that are less than ideal for golf. This vulnerability is expected to increase with the changing, wetter climate.
For more background on groundwater pumping at the golf course property, please read a previous project update from July 2019: Facts and Misconceptions: Groundwater Pumping and Dredging
Over the winter the Minneapolis Park and Recreation Board will publish project updates about the following topics:
- CAC Priorities (posted Dec. 13, 2019)
- Groundwater Pumping (this update)
- Golf Course Layout
- Detailed Master Plan Process and Schedule
- Release of the Draft Preferred Design Alternative
General Master Plan Schedule
- Develop and publish Draft Preferred Design Alternative
- Collect feedback on Design Alternative via open house event and online survey
- Finalize Draft Preferred Design Alternative and create Draft Master Plan
- Draft Master Plan published for 45-day public comment period
- Present Draft Master Plan to Board of Commissioners (informal presentation, no vote)
- Tabulate public comments received
- Finalize Master Plan based on public comments
- Bring Final Master Plan to Board of Commissioners
- Public Hearing and consideration by Planning Committee
- Master Plan passed out of Planning Committee considered by full Board of Commissioners
- Master Plan approved by Board of Commissioners sent to the Met Council for review and approval