Renton is entering the peak period of its water use – summer – with the assurances the city can meet the demand for water.

But that doesn’t mean that residents and businesses, or the city, should water those lawns at will. It’s just the opposite.

The City of Renton has stepped up its water-conservation message under a new agreement with Seattle Public Utilities that will ensure the city will have the water to meet short-term needs and to meet growth demands for the next 50 years.

The special section inside today’s Renton Reporter, Conservation Starts With Us, is an example of the city’s and SPU’s efforts to promote conservation. The city already has had extensive information about water conservation on its website.

“Concern over finding access to affordable water sources, in order to meet population growth expectations, is a major challenge for many cities,” said Mayor Denis Law. “Having this 50-year agreement with SPU assures that Renton will have all the water we need to meet our future growth projections.”

Today, Renton gets its water from city-owned wells that tap into the city’s aquifer, a large underground pool of water that’s constantly recharged naturally but also drawn down by human use.

The city has mandated limits how much water it can withdraw from the aquifer, for a peak use such as on a hot summer day or for an entire year. These are the city’s water rights.

The city also knows it doesn’t have enough rights to provide water for all the residences and businesses that will exist in the city at full buildout under today’s zoning. Buildout is forecast to happen around 2028.

Under the agreement with Seattle, which was effective Jan. 1, Renton will buy as much water as needed from Seattle, using interties between the Seattle and Renton water systems. Previously, Renton had a water-supply agreement with Seattle, but that was for limited supplies during emergencies or as backup.

“Seattle supply basically completes the city’s needs,” said Lys Hornsby, the City of Renton’s utilities systems director. “With time, we will start using that supply.”

But, first, Renton would prefer “to optimize and maximize” its own source of water, said Hornsby, through a water-conservation program.

The issue is the cost of the water.

“It’s cheaper for use to use our own water,” said Hornsby, due to the higher cost of buying water wholesale from Seattle.

The City of Renton could have sought out another water supply, but a new supply would be more expensive to develop than buying from Seattle’s existing supply, she said.

Using Seattle water when needed “is the best deal for us,” she said.

Whether Renton will need to use Seattle water this summer to water lawns depends on the weather, which is variable and makes the water use variable.

But staying within the city’s well water right is easier to manage, knowing the Seattle water is available, she said.

Right now, the city’s water supply is “sitting pretty,” she said, but there hasn’t been any hot weather.

As part of the SPU agreement, the City of Renton is now part of a partnership that regionally is promoting water conservation.

“The more water we can leave in the streams, the better stewards we are of the water, the more it is available for others to use,” Hornsby said.

The agreement with SPU doesn’t require that Renton conserve water, which is mandated under other regulations, she said. The city sets its own water-savings goals.

The city doesn’t talk in terms of having a family of four, say, cut its water use by 300 gallons a year.

Instead, the city is educating residents and businesses about how to conserve water, through product-labeling programs such as WaterSense or buying products such as washing machines and toilets that use less water. Rebates are available for many of those products.

“We know those save a lot of water,” Hornsby said, which the resident does automatically.