Our Gem: Coeur d’Alene’s Water Consumption and Conservation

The City of Coeur d’Alene Water Department provides potable water to over 50,000 customers in and around the city. The public water system was originally constructed and owned by a private water company known as Idaho Water. The city acquired the public water system in 1977, inheriting the entire service area, which includes some surrounding rural areas.

As the city has grown, the Water Department has worked to move from a single-lake water source to multiple groundwater source points. Planning for long-term development has routinely been included to compensate for the anticipated growth and increasing water demand.

The City’s public water system has experienced unique water-consumption challenges this summer. Very little rainfall since early May, coupled with an abnormally long period of extreme temperatures, caused irrigation to increase significantly. The high consumption put a strain on existing infrastructure.

The Spokane Valley Rathdrum Prairie (SVRP) aquifer has ample capacity to support the current population and moderate growth. However, Coeur d’Alene’s public water system is limited by water rights and existing infrastructure. The City’s 10 existing wells can produce nearly 44 million gallons per day (MGD). On July 1, the peak day consumption hit 42.76 MGD more than a month earlier than normal.

The Water Department made a call to action for voluntary assistance from our customers to prevent a water shortage. Thankfully our wonderful customers listened and helped us get through the worst portion of the season.

Public water systems are required by the Idaho Department of Environmental Quality to prepare for long-term growth through coordinated comprehensive improvement plans. The city updates our plan every 10 years, looking at patterns to forecast annual growth, anticipated water use and overall demand. It takes about three years to plan and construct a new well or storage facility.

However, a long-term plan cannot account for sudden housing booms or record heat waves.

What are we doing to compensate for increased water use? Per the planned schedule, a new well is under construction and was expected to be online by this July. Then COVID hit and supplies, materials and equipment became difficult to acquire. Projects came to a halt. What should have been done by July will now be complete in mid-October.

Here are a few tips for our customers to help conserve water and save money. Most irrigation systems are only 30 to 40% efficient. They are often poorly designed and constructed, use the wrong pressure or are poorly maintained. Most turf only requires about 1 inch of water per week, or a little over 0.6 gallons per square foot. At only 30% efficiency, systems require 1.8 gallons to achieve that necessary 0.6 gallons of water.

What can you do to increase efficiency?

Tune-up your irrigation system. Check that you have matching heads and they spray head-to-head in a uniform pattern. Check the system monthly for broken heads or leaks.

Adjust cycles to keep the grass green, not saturated. Adjust seasonally as precipitation and temperatures change.

Run systems in late evenings or early mornings, when temperatures are cooler.

Properly winterize the system to ensure a simple spring start-up. Test your backflow assembly in the spring.

Check the pressure. Optimal pressure is 30 – 45 psi. Too much is just as bad as too little.

Consider low-use heads such as MP Rotators.

Consider installing low-water-use landscaping, such as xeriscape and rock gardens. Drip irrigation is up to 90% efficient.

Please call the Coeur d’Alene Water Department any time for assistance at 208-769-2210.

This article was guest-authored by Terry Pickel for the Our Gem Collaborative, a team of committed and passionate professionals working to preserve lake health and protect water quality by promoting community awareness of local water resources through education, outreach and stewardship. Our Gem includes local experts from the University of Idaho Community Water Resource Center, Coeur d’Alene Tribe Lake Management Department, Idaho Department of Environmental Quality, Kootenai Environmental Alliance, Kootenai County, Coeur d’Alene Regional Chamber and CDA 2030.