Arid land communities like those in northern Nevada get essentially almost no rain. Nearly all water needed to supply cities, farms, and industry accumulates as snow in nearby or distant mountain ranges melts and runs down into rivers used to irrigate crops, sustains fish and wildlife, and quenches the thirst of American Indian communities and urban dwellers.
As average temperatures increase, more of the area’s winter precipitation falls as rain instead of snow, dramatically reducing the amount of water that would typically melt, run down, and feed into rivers. In 2015, the recorded snowpack in the Sierra Nevada Mountains was at its lowest level in over 500 years.
Although near-normal snowpack has been recorded so far in 2016, Nevada remains in drought due to the gaping deficiency in water supply that occurred over the last four years. The region is facing tough decisions in a world where climate change could mean little to no snowpack, speakers said at the AAAS Annual Meeting.
Nevada makes a good case study for predicting how communities that depend on snowpack for water supply -- 50% of the global population -- will fare under a changing climate. Over the last 100 years, average temperatures in the Sierra Nevada mountain range have increased, tracking nearly exactly with the global average temperature increase.
American Indian tribal communities who reside near the terminus of the Truckee-Carson River system in northern Nevada are especially vulnerable to declining water supplies. In a region with such a fragile water system, uncertainty about the future of traditional life ways, hunting, fishing, and farming looms large.
The Truckee river begins at Lake Tahoe, where snow melting down the mountains starts its journey. Fed by snowpack, the river threads along I-80 through the Reno-Sparks area, its natural flow leading northeast toward the majestic, bright blue Pyramid Lake. River water is diverted by the Derby Dam into the Lahontan reservoir, and a separate, nearby river called Carson also is diverted by dam into Lahontan.
Farmers and ranchers whose livelihoods depend on the Truckee in order to grow crops and raise livestock are grappling with the question of how to plan for the unknown. What will the impact of climate change on an already severe drought situation mean for managing water, lands, and natural resources?
“You can analyze your hundred plus years of data and you can use your best judgment to guess on what you think is going to happen, you know, looking at all these particular occurrences equal to this day, but you still don’t know what’s going to happen,” said Mervin Wright Jr., hydrologist and environmental manager for the Pyramid Lake Paiute tribe.
In recent years, cattle ranchers on reservations have cut back on the number of livestock raised, burdened by the lack of water needed to sustain them. Being forced to shrink herds is not good for business. Farmers are investigating alternative, drought-resistant crops that may not require extensive irrigation. In the meantime, they are forced to make tough decisions on which fields to irrigate and which to leave parched.
(from left) Maureen McCarthy, Loretta Singletary, Karletta Chief, and Derek Kauneckis at the 2016 AAAS Annual Meeting. | Boston Atlantic Photography
Once bustling wildlife activity has noticeably quieted down. The Canada Geese, tundra swans, pelicans, and other migratory birds that frequent tribal wetlands in normally healthy water years are no longer there because wetlands have dried up. Moreover, the ranchers that once used the wetlands for cattle grazing can no longer do so.
These are just a few of the palpable effects of drought on communities that rely on snow-fed rivers. As part of a federally funded project called Water for the Seasons, scientists are partnering with tribes in Nevada to study the Truckee-Carson River system in order to predict how the region will handle future weather events and help develop new policies to adapt water management to fit the changing weather patterns.
In the long term, the project aims to develop an integrated suite of models that can be used by water managers and water right holders to assess the impacts of climate change and prioritize adaptation options.
Another project, called Native Waters on Arid Lands, is leveraging the research being done on the Truckee-Carson River system to explore the impacts of climate change on tribal reservations not only in Nevada, but throughout the American Southwest.
Scientists along with scholars and community leaders from over a dozen tribes in the American Southwest are integrating western science and traditional knowledge with the goal of analyzing how warming temperatures and reduced water supplies impact crop and livestock production, fish, wildlife, ecological abundance, and other factors key for sustaining life on the reservation and along with it cultural traditions that have persisted for thousands of years.
[Credit for associated teaser image: Flickr/Doug Jones]