Carson increases water supply with closure of Ash Canyon
With the stroke of a pen, a water treatment plant closed in Ash Canyon, yet Carson City emerged with a larger water supply, perhaps substantially larger.
The Marlette-Hobart Agreement spells out a recipe for more water for Carson City, while the state of Nevada withdraws from the water treatment and distribution business in the capital city.
The agreement, formally signed in January by the Carson City Board of Supervisors, ends an archaic era that once had side-by-side water systems separately serving state facilities and the rest of the city.
The parallel state and city water lines became a single, city-operated water distribution system in 1987. But the state continued treating water in Ash Canyon on the city’s west side until shutting down the ailing treatment plant in July.
All water treatment for Carson City now is done at the city’s Quill Ranch Water Treatment Plant in neighboring Kings Canyon.
The Marlette-Hobart Agreement consolidated water operations under the Carson City Utilities Department while working out a win-win arrangement for the city and state regarding water supplied from the state-owned Marlette and Hobart reservoirs.
The agreement brings more water to Carson City while dropping costs to both the city and state.
“We had to get out of the business of water treatment,” said Mike Meizel, administrator of the state Buildings and Grounds Division. “This allows us more money than we were making on the treatment plant to plow into the system (bringing water from Hobart). We’re probably going to have $20,000 to $30,000 every year to put into the system.”
The state faced improvements upward of $1 million to bring its treatment plant in compliance with the 1992 Safe Drinking Water Act. The plant produced only 7 million gallons of treated water in 1998, even though its capacity was 350 million gallons.
For much of the 1990s, the state treatment plant limited production to about 250 million gallons a year – about double the amount needed to supply state facilities in Carson City.
Meizel reasoned all water treatment should be done by a government entity dedicated to such a task. Thus all treatment was handed off to Carson City in exchange for a water deal.
In the agreement, the city gains 800 acre feet in water rights without having to purchase the water rights. In addition, the city now pays 25 cents per 1,000 gallons of raw state water rather than 62 cents for water treated at the state plant.
Conversely, the state agreed to pay the city 85 cents per 1,000 gallons of treated water, up from 62 cents but lower than the standard $1.05 commercial rate.
For Carson City, more Marlette-Hobart water gives the city a comfortable water supply for the population to swell to about 75,000 people. That is the expected population once the land available for development is used up.
“This puts Carson City in a very good position for the long-term future,” said Tom Hoffert, the city’s utilities operations manager. “With this, Carson City has enough water rights to meet the projected grow out with a margin of safety. It gives us a stable water source.”
The initial 800 acre feet of water rights gained with the agreement were added to the 16,155 acre feet of water rights the city already owns. An acre foot is about 330,000 gallons, the amount of water typically used by a family of four in one year.
Better yet, Hoffert said, all the new Marlette-Hobart water is surface water, not ground water that must be tapped at one of the city’s 24 wells.
“This fits extremely well into our overall management plan,” Hoffert said.
Carson City strives to use more surface water than ground water. Last year, surface water made up 59 percent of the water distributed in the city.
Before the agreement started being implemented last summer, the city received between 3 and 6 percent of its water from Hobart or Marlette. That amount will grow to 15 percent this summer with the potential to grow more.
Marlette-Hobart has supplied Quill Ranch with an additional 500 gallons of water per minute since July 1999. That amount is set to double to 1,000 gallons this July once a new pipeline links the state and city facilities, Hoffert said.
“This is a good water quality source, which makes it even better,” Hoffert said.
The new water will allow Quill Ranch to increase annual production from 1.2 billion gallons to 1.7 billion gallons. Before flows reach that amount, though, the city needs to replace the 250-foot linking pipeline.
The $50,000 to $60,000 project this spring will replace a pipeline that varies in diameter from 6 to 8 inches with a 10- to 12-inch pipeline able to pump 1,000 gallons per minute.
Simultaneously, improvements to Quill Ranch will double the city’s treatment capabilities from 3,200 gallons per minute to 6,400 gallons. The city gets most of its surface water from Kings and Ash canyons and, in the past, leftover water from Marlette and Hobart not treated by state.
With more water and a higher rating at the treatment plant, Carson City will be in a position to produce – and store – surplus treated water for use in drought periods.
The surplus will be stored in an underground natural aquifer rather than a storage tank. Hoffert will drill a test well in March or April with the aquifer recharge system expected to get full approval in about two years.
This well will involve depositing treated water into an aquifer with such high quality water that the mixture may be used straight from the ground, Hoffert said.
But that’s all insurance. Carson City wants to draw most its water from surface sources. Marlette-Hobart has the state selling a minimum of 525 million gallons of surface water a year to Carson City – nearly half the amount used in Carson City.
Right now, all the water is coming from the Hobart Reservoir above Lakeview Estates. Marlette Lake could add another 1 million gallons a day or 365 million gallons a year, Meizel said.
The new Marlette-Hobart water now supplies the equivalent of one production well and the same amount as two wells once the volume increases to 1,000 gallons per minute.
“This delays the need to drill new wells by one or two years,” Hoffert said.