The city of Santa Fe handily came through the worst six-month drought for January through June on record without making residents give up outdoor watering, thanks to a 40-year water plan and a new river-diversion project.

Now city water planners want to revamp Santa Fe's long-range water plan to make allowances for even worse water shortages expected due to climate change.

A federal grant recently awarded to the city, Santa Fe County and the Albuquerque Area Office of the U.S. Bureau of Reclamation will help pay for the expertise to include climate-change data in the existing computer water model.

City water staff discussed the grant with the city Public Utilities Committee on Wednesday evening.

The city, county and the Bureau of Reclamation were awarded a $197,990 federal cost-share grant to model how impacts projected for the region from climate change will affect water resources.

Currently, the city has four sources for water: reservoirs east of Santa Fe, wells in the city, the new Buckman Direct Diversion project on the Rio Grande and the Buckman well field near the river.

The direct diversion of Rio Grande surface water became available early this year, helping sustain the community through this year's drought.

But city staff members think new information and data regarding the impacts of climate change on water resources make it important to revisit the plan and ensure there will be water under even worse conditions. According to a 2007 report from The University of New Mexico and New Mexico State University, a trend of warming temperatures and less snow in the Southwest will impact water in the state and in Santa Fe. More warm days could mean longer growing seasons, which also could mean that people use more water each year on farms, gardens and landscapes.

Any impacts from climate change will come on top of the historic probability of a long-term, multiyear drought, based on evidence of past dry spells in the Southwest.

A few years ago, city water planners worked with other organizations to develop a computer model called Santa Fe WaterMAPS (Water Management and Planning Simulation). The model allows planners to plug in variables — such as the amount of available water in reservoirs, the amount of snowmelt runoff expected and the amount of water residents are likely to use — to predict how much water is available and how much is needed. The city can switch among the sources of water as needed. Using more surface water from the river-diversion project and the reservoirs, for example, allows city water managers to rest wells. This year, when the massive Las Conchas Fire that burned near Los Alamos and across Santa Clara Canyon sent ash into the Rio Grande, the city turned off the diversion project and switched back to reservoir and well water.

Among options city officials and planners can consider if additional water supplies are needed:

• Increased use of treated wastewater.

• Increased water conservation.

• Better control and reuse of storm-water runoff.

• Additional water storage above and below ground on the Santa Fe River.

Contact Staci Matlock at 986-3055 or smatlock@sfnewmexican.com.

MAPPING OUT CLIMATE

Want to know more about potential impacts in New Mexico associated with climate change? The Natural Resources Defense Council, a national nonprofit environmental group, has taken data on temperature, precipitation and other factors from all 50 states and created climate maps. The model compares data from 1961 to 1990 with data from 2000 to 2009. Find the maps at www.nrdc.org/health/climate/.