Southeast Boise’s water supply is shrinking. That leaves little room for growth

This story was originally published on March 6, 1994.

Boiseans will soon face the hard reality that we live in a desert.

Although most of the city sits over a vast underground supply of water, some parts of town do not.

Southeast Boise — where 19 percent of the city’s population lives — depends on a small aquifer that’s geologically distinct from a much larger underground supply serving the rest of Ada County. Until now, the Boise River has naturally replenished that aquifer. But the faster Southeast Boise grows, the less that natural process keeps the aquifer full.

There’s enough to provide water to homes and businesses in the area now, said Ed Squires, a Boise Water Corp. hydrogeologist who also serves as a research associate at Boise State University’s Department of Geosciences. However, Squires added, “we could have a problem in five years” if alternatives aren’t explored and the area continues to develop at its current rate.

There is no additional supply of water north of the Boise River, where 33 percent of the city’s population lives.

Development north of the river can continue to occur, but Boise Water Corp. wll have to take water from the river and treat it for drinking to serve new homes and businesses.

Providing water to our growing valley in the future means it will cost more to build. It also may shift development from one part of Boise to another.

“Water is the critical growth issue for this community,” said Cathy Chertudi, with the Boise City Public Works Department.

Where the problem is

The problem is most acute in the southeast. Water levels have dropped rapidly during the past decade as more and more wells were drilled to pump out groundwater. Water levels in other parts of the city have not shown a decline, said Squires, who has monitored 10 deep aquifer wells since 1988.

About 27 percent of the city’s residential growth — 10,000 people — plopped down in Southeast Boise between 1980 and 1993. About 26,000 residents currently live in the area, which still has 4,300 acres of vacant land. That represents 17 percent of all the acreage left in the city.

Another 20,000 residents are expected to move into the area in the next 20 years, according to the Ada Planning Association.

The water shortage “has made our job a lot more complicated,” said Wayne Gibbs, director of the Boise Planning Department.

Boise Water’s options

Boise Water thinks the area could sustain growth if there were a change in the way people used water and if another water treatment plant were built.

The company has two options: Drill recharge wells into the depleted southeast aquifer and pump in water from the Boise River to fill the aquifer back up. Or transport water via underground pipe from areas of surplus such as west Boise.

Company officials said building the pipeline would cost a minimum of $2 million to $3 million. A system to pour water back into the aquifer would cost at least $1 million to $2 million.

Boise Water president Wayne Booe said his company hopes something could be built within two to five years.

Footing the bill to supply water-poor parts of the city will be either new homeowners or the Boise Water Corp.’s entire customer base.

The Idaho Public Utilities Commission, which regulates the company, would decide. The PUC staff leans toward requiring new development in the southeast to pay the tab.

And there is another option.

Given the price tag attached to southeast growth, it may be a good idea to send newcomers to the southwest, Gibbs said. That area has the advantage of abundant groundwater and lots of open land, he said.

Water studies ongoing

Studies a decade ago indicated the main water supply that serves most of Ada would start to run out when the population reached 300,000. (Today’s population is around 230,000.)

But more recent research found the water supply is much bigger than previously thought, said Ben Hepler, general manager at Boise Water Corp.

To force growth to shift to the southwest, the city could clamp down on southeast development through zoning. Average density there is now 4.5 units per acre. That may have to drop to three units per acre, Gibbs said.

There’s one big problem with doing that, Gibbs said. “A lot of people out there (in the southwest) don’t want growth.”

Gwenn Cammann is one.

“Everything compounds with growth,” said Cammann. She and her husband built their home in Southwest Ada County two years ago.

“You have more traffic, more pollution, more noise, more crime. Everything multiplies,” she said. About 21,000 people live in the area now.

On the other hand, Ray Spencer, who owns 40 acres in the southwest, welcomes growth.

Spencer belongs to the Southwest Community Landowners Association, whose members “own most of the bare land out here.” City planners said there are 6,300 acres of open land in the southwest 25 percent of the city’s remaining acreage.

The Landowners Association consists of farmers and other residents who want the opportunity to eventually sell their land for a good profit, Spencer said.

The lack of groundwater north of the Boise River doesn’t pose as big a problem as in the southeast.

Boise Water Corp. is building a water treatment plant that can be expanded from a production of 8 million gallons per day to 16 million gallons.

It would cost $3.2 million to fully expand the plant, and those costs would likely be passed on to new development.

It’s questionable whether more plants would be needed. But if so, that would raise the cost of water dramatically, said Randy Lobb, a PUC analyst.

“The more treatment plants you have, the more expensive the water,” he said.

This story was originally published October 25, 1994 at 12:00 AM.