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December 4, 2018
The advisory group for the North and East Metro Groundwater Management Area met for its second semi-annual meeting of 2018 on October 26, at Hugo City Hall. The meeting included updates on implementation of the area groundwater management plan, highlights of local water management efforts by the cities of Hugo and Cottage Grove, and a summary of DNR’s use of its new groundwater model to look at the impacts of pumping on White Bear Lake.
Using stormwater to reduce groundwater pumping
One way to conserve groundwater is to use alternate sources of water for applications that don’t require the quality of water from a public water supply. Hugo’s city administrator Bryan Bear summarized efforts the city has taken over the past few years to make greater use of stormwater for turf irrigation. Initial efforts included using stormwater ponds for watering a golf course and soccer fields. Subsequently, the city identified stormwater ponds in an existing residential neighborhood to pipe the runoff water from the ponds to the homes for lawn watering. Now they’re turning their attention to single-family neighborhoods and new developments.
Hugo has looked at other water conservation efforts such as water rates, regulations, education and incentives for efficient plumbing fixtures, but none has made as much difference as stormwater utilization. By undertaking these efforts, the city has reduced anticipated water needs outlined in its 2030-2040 comprehensive plan from 11 wells and four water towers down to seven wells and three water towers – a significant capital savings. In addition to saving money and conserving groundwater, stormwater re-use enhances infiltration, improves water quality and reduces flooding, Bear said.
Mission accomplished in Cottage Grove
When the city of Cottage Grove found out in May 2017 that eight of its 11 city wells did not meet newly established health-based values for PFCs as a result of industrial contamination, city officials set themselves a goal that seemed like a municipal version of Mission Impossible: to design and build two interim water treatment plants to remove the contaminants in 90 days. Jennifer Levitt, Cottage Grove’s community development director and city engineer, provided a detailed overview of the city’s carefully plotted response to the situation.
With less than half of its municipal pumping capacity left, the city declared a state of emergency and implemented a citywide watering ban to reserve water for essential uses. Even with community meetings and careful messaging, the watering ban proved contentious, with factions coalescing around public health versus green lawns. Elected officials stepped up to the plate and carried the burden of that decision, Levitt said. Site selection, permitting, grading, footings and foundations – everything proceeded like a fast-tracked military operation, with the treatment facilities operational by day number 86—an accomplishment made possible by strong partnerships and contractors willing to work long hours and on holidays.
Model shows sustainable groundwater use near White Bear Lake
Jason Moeckel, DNR inventory, monitoring & analysis section manager, walked attendees through developments related to the DNR’s groundwater model to better understand the relation between groundwater pumping and White Bear Lake water levels. After updating the model with more recently available data, the DNR used it to answer several questions pursuant to an August 2017 court order. DNR’s findings were published as a three-page insert in the White Bear Press on Oct. 17. Copies of the published results also were handed out at the advisory team meeting. When the groundwater model was used to analyze pumping from all permitted wells within five miles of White Bear Lake, it showed the following:
- Groundwater use has been declining;
- Current groundwater use complies with Minnesota’s groundwater sustainability standard;
- Current groundwater use has contributed to water levels falling below the recently established protective elevation for White Bear Lake;
- Temporary irrigation bans within nearby cities would not have a significant effect on water levels in White Bear Lake.
Water levels in White Bear Lake fluctuate naturally. These fluctuations benefit lake health by promoting the growth of vegetation that provides aquatic habitat and stabilizes shorelines. The model shows that pumping groundwater increases these fluctuations, particularly on the lower end of the lake’s water level range, making the lows lower. The model also demonstrates that groundwater pumping by some permitted uses effects water levels of White Bear Lake more than others.
While current groundwater use does not violate the groundwater sustainability standard, lower water levels, particularly those below 922 feet (protective elevation for WBL), do disrupt or diminish some recreational uses of the lake. Moeckel summarized his presentation by describing that with the new model, the DNR is now able to work with permit holders having the greatest influence on White Bear Lake, to identify potential changes to water use that can help support recreational uses of the lake. The summary of the analysis and the groundwater technical report can be found on the DNR website: www.mndnr.gov/gwmp/wbl.
Plan implementation update
DNR project manager Dan Miller referenced handouts that provided a detailed summary of recent appropriations permit activity, and progress on implementing the North and East Metro Groundwater Management Area plan. Highlights included greater use of DNR Geologic Atlas Program information, staff reviews of north and east metro communities’ water supply plans, and establishment of a new weather station at William O’Brien State Park to provide more local climatological data.
Next meeting
The North and East Metro Groundwater Management Area advisory team will next meet in spring 2019, at a location yet to be determined. A meeting announcement detailing the date, time and location will be sent out in advance to everyone signed up to receive North & East Metro Groundwater Management Area email updates. You can subscribe here: https://public.govdelivery.com/accounts/MNDNR/subscriber/new.
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