Coming off a slightly soggy holiday weekend, it may seem like a strange time to talk about water conservation. But that’s a subject we work on frequently at Rosemount City Hall. And with residents’ help, we can save on water - and they can save on water bills.
Providing a clean, reliable source of water takes a big investment. The city is currently building its ninth municipal well on Bacardi Avenue north of Bonaire Path at a cost of $1.45 million. We’ll soon need a new storage tank, which will cost about $4.1 million.
Those investments are needed to support Rosemount’s growth in the near term. But with determined efforts at conservation by the city utility and its customers, we may be able to delay the next well and storage facilities.
And of course summertime is the prime time to think about water conservation. The period from June through September typically accounts for 55 percent of water usage in Rosemount. Meeting that peak demand requires extra storage and wells. Again, if we can reduce the peak, we can put off spending on the system.
Rosemount has long had sprinkling restrictions from May through August, prohibiting watering lawns between noon and 6 p.m. when evaporation is the highest. Outside those hours, sprinkling is limited to odd-even days based on street address numbers.
To comply with state regulations, our utility prices water so large users pay a higher rate per gallon. That may have helped reduce the amount of water we bill annually in Rosemount from 93 gallons per person in 2012 to 75 gallons per person last year. And no question, the fact the summers were wetter also helped.
On a wider scale, the city is working with the Metropolitan Council to monitor the levels of the sources of our drinking water: the aquifers deep below us. The Met Council and the Minnesota DNR are concerned about the declining levels of those underground supplies. Rosemount and its neighbors are working to study the trends and make sure we can avoid depleting groundwater.
One way to do that may be to tap into treated effluent for reuse. The Met Council has a discharge pipe that goes east along County Road 42 on its way to the Mississippi River. If there are ways to treat that liquid so it can be diverted for industrial or non-drinking uses, we can avoid putting additional pressure on the aquifer. Just last week the council heard a discussion of that strategy as part of a presentation by University of Minnesota law students taking part in the Resilient Communities Program that has focused on Rosemount this year.
On the other hand, a switch from water wells to river water would be expensive. The estimated cost for Rosemount and seven nearby cities to use river water is $1.1 billion in construction costs alone.
There are simpler steps each of us can take to conserve water. An example is to leave grass clippings from the lawn when you mow. The clippings can provide shade and reduce evaporation.
Turf experts typically recommend only one inch of water per week for turf grasses. Adjusting irrigation systems to achieve this rate combined with rainfall can reduce water usage. The city has been working to monitor and calibrate our own irrigation systems. It has resulted in a 10 to 20 percent reduction in water usage for city parks.
Inside, don’t run the dishwasher and clothes washer until you have a full load. You can find other tips on our website at ci.rosemount.mn.us/conserve.
Here’s hoping for a pleasant summer that doesn’t hurt our greenery or run up our water bills.
Mayor Bill Droste authored this column.