Some towns across Colorado have declared water restrictions following weeks of hot summer temperatures and drought conditions that have marked the parts of state.

The restrictions, depending on the town, include limiting lawn watering to no more than three days per week, not watering between 10 a.m. and 6 p.m. or at any time when it is raining.

Sound familiar?

It does if you’re a Denver Water customer.

That’s because many elements of these mandatory restrictions mirror Denver Water’s standard annual summer watering rules in place since 2005. With those efficient irrigation practices set as the standard in Denver and customers’ long-term efforts to use less water, Denver Water hasn’t had to impose additional restrictions this summer.

But water planners are keeping wary eyes on weather patterns, hoping this winter will be full of snow and lead to healthy runoff levels next spring. The two river basins that Denver Water relies on, the South Platte and the Colorado, will receive particularly close attention.

“We look at a lot of indicators, including supply conditions, weather patterns, stream flows and storage levels. A large factor in our decision-making is what we see our customers doing in terms of water use, which was impressive from an efficiency standpoint this summer,” said Greg Fisher, manager of demand planning for Denver Water.

As the summer started, with weeks of temperatures in the 90s and days when the gauge crept over 100, Denver Water’s customers used at least 20 percent less water than in similarly hot, dry stretches in past years. The reduction comes despite significant population growth.

"Our customers' everyday awareness and responsible watering practices have stretched our water supply," Fisher said. "When the monsoon rains hit we saw water use drop by 100 million gallons per day because customers reacted to the rain by conserving water."

Jason Finehout, Denver Water’s drought preparedness coordinator, also credited metro-area water users for helping Denver’s water storage situation this year.

“Since customers are already being efficient with their water use, we don’t need to seek additional reductions during every hot and dry spell we see,” said Finehout.

“Therefore, customers know we’re not crying wolf when conditions warrant seeking additional restrictions to manage our supply during a drought.”

Denver Water imposed mandatory water restrictions during the 2002 drought to keep water in the reservoirs and stretch existing water supplies.

Key elements of those early restrictions were never lifted. Rather, they were adopted by the Denver Board of Water Commissioners in 2005 as the organization’s standard approach to using water wisely and efficiently in a dry, semi-arid climate.

For Denver Water customers, lawn watering is not allowed between 10 a.m. and 6 p.m. They’re warned to water “no more than three days per week” and cautioned against watering in the rain, when it's windy, and wasting water on streets, gutters, concrete and asphalt.

Customers who don’t follow the rules can receive warnings, with the potential for fines and even being cut off from service if there are repeat violations.

Elements of Denver Water’s standard efficiency rules, including the potential for warnings and fines, can be found in the new, mandatory restrictions imposed this summer elsewhere in Colorado.

Aspen in mid-August imposed Stage 2 mandatory restrictions, including limiting lawn watering to no more than three days a week and no more than 30 minutes per sprinkler zone per day.

Also in August, Grand Junction declared mandatory restrictions on lawn watering. Its 9,700 customers were told to limit lawn watering to three times per week in August, two times per week in September and one time per week in October.

In Denver, outdoor water use is expected to tail off as cooler fall weather sets in.

But Denver Water didn’t escape the hot summer unscathed.

Our reservoir levels fell below the five-year average in June. As of Sept. 10, levels stood at 85 percent, six points below the historic median of 91 percent full for that time of the year.

What happens this winter and next spring will dictate whether Denver Water customers will be asked to take additional steps to conserve precious water supplies.

“We don’t know what the winter will bring. It could be a good snow year with a good runoff next spring, or not. We are always monitoring drought conditions and, although things are not at a restriction point yet, we are ready if they get there,” Finehout said.