By Lance Green

This is the second in a series of monthly articles supporting Monona’s Year of Water 2012. Here we examine where our city’s water comes from and where it ends up.

In 2010, the Monona Water Utility pumped nearly 360 million gallons of water from two wells (one 500 feet deep, the other 800 feet deep). Our water use follows seasonal patterns, with up to one million gallons per day pumped in mid-July and fewer than 100,000 gallons in mid-December. The water travels through about 40 miles of water mains to our houses, businesses, schools, and churches. Two elevated water towers, built in 1957 and 1983, hold 500 thousand gallons and help maintain proper pressure to serve the needs of the city’s 7,533 citizens. About 2,700 water meters track our usage so that the Monona Water Utility can bill us appropriately.

All of Monona’s water is pumped from a sandstone aquifer several hundred feet below us. Under natural conditions, precipitation soaks into the ground and percolates downward though sand and gravel layers, eventually recharging the aquifer. But increasing quantities of hard, human-made surfaces are limiting natural recharge.

Another challenge to recharge is that because water moves very slowly through aquifers, high-capacity wells pumping large amounts of water can cause long-term, cone-shaped depressions, called drawdowns, in the groundwater level.

In some areas of Dane County, water table levels have declined over 60 feet since pre-settlement days, requiring deeper wells and increasing pumping costs. The declines have also reduced the flow of groundwater into lakes, streams and wetlands.

In fact, drawdowns have caused the flow of groundwater in some areas to change direction: where the aquifer used to feed water into the lakes, the aquifer is now drawing water away from the lakes.

Diagram courtesy of the Nine Springs Recharge Project

Where does all that water go after we use it? Wastewater from Monona, Madison, Middleton, Verona, Fitchburg and most area villages and towns is pumped to the Nine Springs Wastewater Treatment Plant on Moorland Road, a mile south of Lake Monona. This facility, operated by the Madison Municipal Sewage District, treats over 15 billion gallons of wastewater annually. After the grit, solids, and sludge are removed, the treated water is disinfected by ultraviolet irradiation, and then pumped to Badfish Creek and Badger Mill Creek, eventually flowing out to the Rock River and on to the Mississippi.

So, with the water we use flowing out of our watershed, how can we replenish our groundwater? We can slow down the depletion through increased conservation. We can create more opportunities for water to naturally soak back into the earth when it rains through better stormwater management and fewer hard surfaces. And, in the future, we may possibly be able to recycle our wastewater to help recharge the aquifer.

Last year, graduate students from the Water Resources Management Program at UW-Madison collaborated with the Madison Metropolitan Sewerage District and the City of Fitchburg on the Nine Springs Recharge Project. The goal was to determine if treated wastewater from the Nine Springs plant could be recycled to recharge groundwater. The study holds promise for addressing groundwater recharge. The results are expected soon.

Watch for upcoming articles on conservation, stormwater retention, and other water issues. Together, our efforts can assure a safe, abundant supply of drinking water for our community.

And join your friends and neighbors for these two January events about water:

• “Energize Monona: The Energy-Water Nexus” on Wednesday, January 25, 6:30 – 8:00 at the Monona Community Center, 1011 Nichols Road.

• “Green Tuesdays – Monona’s Water: Cleaner, Safer, Better” on January 31, 6:30 – 8:00 at the Monona Public Library, 1000 Nichols Road.

Nine Springs Recharge Project: https://sites.google.com/site/9springsrecharge/

Madison Metropolitan Sewerage District: http://madsewer.org/

Monona’s Year of Water 2012: www.tnsmonona.org/year-of-water/