With major western reservoirs like Lake Powell and Lake Mead declining to historic low levels, water officials in New Mexico presented on the dire Upper Colorado River Basin conditions to the Senate Conservation Committee on Thursday.
Estevan Lopez, the state’s Upper Colorado River Compact Commissioner and the governor’s representative on Colorado River matters, spoke about how climate change is impacting the hydrology in the basin.
“Even if we don’t know what’s going to happen to precipitation, we know that temperatures are going up and as a result of that, the precipitation that we do get in the basin…much more of that is precipitation in the form of rain as opposed to snow…When we do get snow, that provides a natural reservoir high up in the mountains where the water is released slowly over time and it spreads the water around for the whole year,” he said.
He said in addition to reducing the amount of snow in favor of rain,hotter temperatures induced by climate change also mean more evaporation of snowpack and surface waters, leading to less runoff into the water system.
Lopez said last year there was a good snowpack, but the higher temperatures led to less runoff than anticipated.
The recent winter storms mean that Lake Powell may have reached its lowest level this year, Lopez said.
“The Upper Basin, overall, we’re doing very well in terms of snowpack this year and this is probably going to be about the lowest we’re going to get this year,” he said.
Lopez said that the snowmelt will start in April and that hydrological models predict that the water in Lake Powell will begin to rise.
“This wet hydrology has given us a reprieve, but we still have to plan for the possibility of a continued drought,” he said.
This comes as the reservoir levels are less than 35 feet above the intake structures to the tubes that take water to the generation facilities. Lopez said if the water continues to drop, devastating damage could be done to the generation facilities at Lake Powell. He said this is because air could be drawn into the tubes and reach the generators. He said the air bubbles bursting could create a tremendous amount of force, damaging or destroying the generators.
The hydropower from Lake Powell is a crucial energy source for the western United States, including New Mexico.
Lopez also said that if water levels drop too far the Upper Basin states will not be able to deliver water to the Lower Basin states because they will not be able to get the water out of Lake Powell due to not having enough pressure.
“We put in place some drought contingency plans and those helped, but they’re simply not enough,” he said.
The federal government and the seven states that rely on water from the Colorado River are working on plans to solve the problem, although a final plan has not yet been reached.
The 1922 Colorado River Compact, which was based upon wet year hydrology and overallocated the water a century ago, has governed management of the Colorado River waters.
In New Mexico, those waters naturally occur only in the northwest corner of the state where tributaries of the Colorado River include the San Juan and Animas rivers.
In the 1950s, a reservoir was built on the Colorado-New Mexico state line in San Juan and Rio Arriba counties. At the top of this reservoir where tributaries of the San Juan flow in, a structure takes water and transports it through a tunnel system to Heron Reservoir and, from there, it is delivered to communities like Albuquerque. That is known as the San Juan-Chama project.
The San Juan-Chama project contracts total about 96,000 acre feet of water and is one of the largest water uses of Colorado River water in New Mexico.
Power plants have historically used about 60,000 acre feet of water in New Mexico, but that is decreasing as coal-fired power plants close. About 40,000 acre feet are currently used for power generation, according to Interstate Stream Commission Director Rolf Schmidt-Petersen.
With the closure of the San Juan Generating Station, New Mexico entered into a lease agreement with Jicarilla Apache Nation to allow it to use 20,000 acre feet of water the Nation once leased to the Public Service Company of New Mexico for power plant operations to meet endangered species and compact compliance requirements.