Hope for a “jubilant” January, a “fabulous” February, and a “miracle” March fell flat this year. The western US, including much of California and Nevada, faces another drought year. The Drought Monitor map shows the Sierra Nevada in “severe drought” along with all of western Nevada. Worse designations of “extreme” and “exceptional” drought categories are found in portions of 8 of the 9 western states.
Truckee River: low flows ahead for spring and summer
After the summer of 2021’s extreme fires and, in much of the west, unprecedented heat, December’s storms seemed to herald an above average water year in the offing for the Sierra. But a record breaking, dry January and February ended the hope that the 200% snow pack would persist. The ides of March has come and gone. Yet, the Sierra snowpack that supports the Truckee River is just 76 and 68 percent of average in the Truckee River and Tahoe watershed today. Lake Tahoe is just 12″ above its natural rim and the very real prospect of a continuing dry spring mean lower flows into the Truckee River below Tahoe City. The traditional April 1 peak snowpack measurement becomes less relevant as climate change warms temperatures winter and summer. The lack of storms in what should be the Sierra “wet season” stretches our multi-decadal drought for yet a further spring and summer.
The National Weather Service forecast model shows the flow of the Truckee River at Floriston, CA peaking by April 27. The extremely dry soils in the Truckee River watershed at both Lake Tahoe and the Truckee Basin are contributing to the lower runoff as well as the below average snowpack this year and last year.
The actual peak in river flows could be earlier if the weather remains warmer than expected or be later if cooler and stormier weather comes in. The 10 day forecast doesn’t appear to offer much in the way of precipitation through the first part of April, however. The Carson and Walker Rivers are also expected to have peak flows early.
Currently, the snowpack is melting fast and earlier than would be indicated by historical data. With an early melting of the snow, rivers and streams will likely be well below their average flow into the first part of the summer. The Truckee River, due to upstream storage in reservoirs and Lake Tahoe, will have summer flows while the Carson and Walker Rivers will likely be dry in early summer in many locations.
It’s easy to miss Derby Dam on your drive east on I-80. Look to your right when the “Derby Dam” exit sign appears and you’ll see an earthen berm and concrete spillway and some of the dam’s control structures. The dam is off limits to the public.
But this diversion dam on the Truckee River brought with it a cascade of negative environmental and social effects by not only stopping all fish migration upstream to their spawning grounds but setting in motion a plunging water level at Pyramid Lake and diverting the flows of the Truckee River through a canal to another basin to create new farms in the desert. The Congressional act that created the diversion dam and canal ushered in a era of damming rivers across the west to the detriment of fish and wildlife and, too often, the Native Americans whose livelihoods depended on the rivers and lakes both on and surrounding their reservations. Today, there is the promise of a “fix” with the construction of a fish screen and fish passage at the dam to provide fish access to the Truckee River’s spawning areas from Pyramid Lake all the way to Lake Tahoe.
The Newlands Project: Promise of irrigation ignored Native Americans
The diversion dam was the first of five irrigation projects authorized after passage of legislation sponsored by Nevada Senator Francis Newlands and built by the newly minted Reclamation Service now renamed the Bureau of Reclamation (Bureau). Completed in 1905, the Newlands Project named after the legislation’s namesake, consisted primarily of Derby Dam connected to a 31 mile long diversion canal – the Truckee Canal.†
Together the structures set in motion the dessication of Winnemucca Lake east of Pyramid Lake, an 80 foot drop in water level of Pyramid, the extirpation of the native Lahontan cutthroat trout in Pyramid Lake in the 1940’s, and near extinction of the Cui-ui fish that the Pyramid Lake Paiute People relied on for food for thousands of years and symbolized their cultural identity. Cui-ui are endemic to Pyramid Lake and migrate up the Truckee River to reproduce. The Lahontan cutthroat trout (LCT) became a threatened species and the Cui-ui endangered under the 1973 Endangered Species Act. The Pyramid Lake Paiute Tribe together with others who wanted to see the restoration of the LCT to Pyramid brought another strain of LCT to Pyramid Lake from a population found on the Summit Lake Reservation in northern Nevada. The fish had to be raised in hatcheries on the Pyramid Lake Reservation because they didn’t have access to spawning areas in the Truckee River any longer.
† Lahontan Dam was built later and completed in 1917 and allowed more diversions from the Truckee River for storage.
More recently the original native strain of Pyramid Lake Lahontan cutthroat trout has been reintroduced into Pyramid Lake. The Cui-ui are successfully spawning using water releases from upstream reservoirs during its spring spawning season. Fish hatcheries operate at Numana and Sutcliffe on the Pyramid Lake Paiute Reservation for the propagation of both species.
Truckee River Operating Agreement and Water Quality Agreement …
… between the Pyramid Lake Paiute Tribe and upstream users have lead to better management of the Truckee River to the benefit of both fish species through improved river flows and water quality. However, Derby Dam and the Truckee Canal remain a blockage to restoring the trout which for millennia migrated the 120 miles from Pyramid Lake up the Truckee River to Lake Tahoe every year to spawn a new generation of fish. The Pyramid Lake Paiute Tribe never gave up on restoring their fishery dependent on the flows of the Truckee River.
Now, the Bureau and the U.S. Fish and Wildlife Service (USFWS) are nearing completion on a nearly $24 million fish-passage project at Derby Dam and the Truckee Canal to help the annual spawning migration of the Lahontan cutthroat trout.
Fish Passage Construction completion slated for Fall 2020
Slated to be completed this fall, constructed fish screens in a “bypass canal longer than a football field” will keep fish from becoming trapped in the canal. An AP article appearing in the Nevada Appealexplained, “The bypass canal will include an 80-foot-wide, 390-foot-long horizontal fish screen — actually a metal plate with slots that pushes water down through the water system while sending the fish and other debris through the side channel”. The article quotes Jody Holzworth, deputy regional director of the USFWS, saying “This day is 100 years in the making. The fish screen will allow this iconic species to travel beyond Derby Dam, from Pyramid lake to their spawning grounds, for the first time in more than a century.”
Dan Mosley, executive director of Pyramid Lake Fisheries for the PLPT, said the people of the tribe have a long history of fighting for the fish which “are really important in our stories and culture.”
Soon it should be possible for the Lahontan cutthroat trout to pass the diversion dam at Derby and have access to the Truckee River all the way to Lake Tahoe. We wish them a safe journey.
In Nevada, as in many other western states, those who first put water to beneficial use (growing a crop or providing drinking water to a town, for example) have a right to use that water over those who come later. Early on most water used in the state came from surface waters such as the Truckee or Humboldt Rivers or smaller streams which flowed from the state’s numerous mountain ranges or from local or large regional springs. Most of the surface waters in Nevada were already claimed before the 1930s. The beneficial uses claimed became water rights. Water rights can be bought and sold.
Native Americans were already here.
Ignored in the claiming of water rights beginning in the late 1850s was the cyclic nature of water availability in the dry Great Basin and Mojave Deserts. Water that is present in a sagebrush covered valley one year may be absent the next one or longer. And while the newcomers claimed the water for themselves, none appeared to notice that the Paiute, Shoshone, and Washoe Peoples already occupied the land and were prior users of the rivers and springs that nourished many wetlands, lakes, and meadows with the wildlife and plants the People depended on for survival. The Indigenous population found that the water that supported their way-of-life for thousands of years was used somewhere else by someone else. The water supplied by the natural world that had sustained them disappeared.
Newcomers claim the water.
Over the decades more and more water claims depleted rivers, lakes, springs, and wetlands throughout the state. Lakes such as Pyramid fed by the Truckee River and Walker fed by its namesake shrank as their river’s flows diminished – or disappeared altogether. And large wetlands on the Humboldt and Carson Rivers shrank as water went to farms and industry.
Taking water flowing in a river, stream, or spring has an immediate effect. For example, consider a small stream that has a flow of 10 cubic-feet per second (CFS)† with two users who each claim 5 CFS. If water user number 1 diverts half of the flow of the stream to an irrigation ditch, then the flow downstream of the diversion is immediately reduced to 5 CFS. The remaining water in the stream continues downstream to water user number 2. When water user number 2 diverts his share, then downstream of the diversion, the stream is dry. In a different year or later in the season, when the stream’s flow is 5 CFS, then water user number 1 diverts all flow and nothing remains for water user number 2. When the stream has 1 CFS, water user number 1 still diverts all the flow, but is unable to get her full water right and water user number 2 again has no water to divert.†† From the environmental perspective, the stream no longer has flow to support riparian trees or meadows below the diversions and eventually, they disappear. Essentially, every year becomes a drought year downstream of the diversion.
† 1.0 cubic-foot per second is approximately 7.481gallons per second. Early miners were among the first to appropriate water in Nevada using “miner’s inch“. Today, Nevada has a legal definition that a “miner’s inch” is equal to 0.025 cubic-feet per second. †† Certain surface water allocations depend on “return flow” when not all the water is consumed irrigating a crop or water is returned to a stream from a sewage treatment facility. “Return flow” can then be diverted by another appropriator.
Water already claimed in rivers and springs.
The appropriation of surface water had negative effects on the rivers and streams and springs, because the original benefits of flow through the river’s environment were reduced. But the cyclic nature of water in the desert continued and when rivers and springs couldn’t keep up with the water users demand and reservoirs shrank, a new group of folks wanted water that they could depend on whether it rained or not. Groundwater pumping was a promise of unlimited supply – that unseen resource just beneath your feet. The promise was a false one and today we face a reckoning of over spending our water bank account on both fronts.
The “new” water: Groundwater.
Pumping significant amounts of groundwater from aquifers was really not possible during the time when most of the state’s surface water was allocated between the various industrial and agricultural users. Beginning in the mid-20th century, however, groundwater extraction with powerful pumps became more and more common. The Nevada State Engineer (NSE) allowed groundwater wells to be drilled for agriculture or other uses even in basins with fully appropriated rivers and streams and springs such as the Humboldt River and the Walker River and around Moapa’s springs. The NSE now admits, in many cases, the overallocation was known at the time, but the NSE didn’t expect that the people getting the permits would be economically successful (an erroneous assumption as it turned out!) or that they didn’t consider the negative effect groundwater pumping would have on rivers and springs. The damage to rivers and springs due to over pumping, however, is a matter of hydrology. The excuses for why it was allowed to continue for decades doesn’t change the negative outcome for river and spring flows and the consequences for the people dependent on them and to the fish and wildlife that can’t survive without them.
In all groundwater pumping, groundwater levels decline by the very action of extracting water and bringing it to the surface. Essentially, a cone-shaped hole develops around the well. If pumping ceases soon after the pumping begins, the cone-shaped hole or depression slowly fills in and after a long enough period of time, it may get close to the original groundwater level, but that generally takes far longer to happen than the length of time the groundwater pumping occurred.
Over appropriating the groundwater.
Over the decades the Nevada State Engineer (NSE) has permitted groundwater users to over-appropriate as many as half of Nevada’s hydrographic basins in the state with the least amount of water. Theoretically, pumping is supposed to be “balanced” by drying out the surface and eliminating plants and water “discharges” (like springs) that use groundwater through evapotranspiration. (Eliminating all evapotranspiration to achieve this “balance” with groundwater pumping can result in a barren landscape increasing dust as well as damaging seeps, springs, and meadows dependent on groundwater.)
Pumping groundwater appears, at first, to be benign. When groundwater pumping begins, it removes water that may be a source of supply to rivers or springs, but the effect of pumping takes time to deplete the flow of a river or spring (see illustration above). The further away the river or spring is from the pumping, the longer it takes. Effects of the State’s overallocation of groundwater and the near complete allocation of surface water are now being felt with continually declining groundwater levels in as many as 50% of Nevada’s basins, but it is also affecting iconic rivers like the Humboldt – the largest river completely contained within the state’s borders. However, no river or stream is immune to the damage caused from pumping of groundwater (or the over allocation of surface water, for that matter). The extent of the pumping, leading to over pumping and continually dropping groundwater levels, harms the environment and leads to conflicts between water rights holders and to discord between and among rural and urban Nevadans.
Nevada water law is clear.
Before approving any water applications, Nevada water law (Title 48, NV Revised Statutes) requires the NSE to find that water is available at the source and it will not conflict with existing water rights. This requirement applies to both the allocation of surface water or groundwater. Nevertheless, the NSE has, in fact, allocated water far beyond the available supply. In the graphic above, those areas shown in “red” are 300% or greater over the available supply and the “yellow” and “green” areas are more than 200% or more than 110% over the available supply, respectively. It is easy to see why conflicts are escalating between and among users and why the environment in many areas suffers from a lack of water.
Nevada State Engineer now wants changes to the law.
The NSE now wants the legislature to change the law to allow the NSE to “deal with” the conflicts his water office has created over many decades (and in contradiction to the law’s provisions.) These changes are embodied in two pieces of legislation the NSE has brought to the 2019 Nevada Legislature – AB30 and AB51. Check out our next blog to see how these could affect our critically important rivers and streams and springs throughout Nevada.
February snow and rain in California and Nevada quickly took a slightly below average winter season at the beginning of the year to well above average by the beginning of March. February snow in the Sierra set a record with as much as 400 inches of snow falling in and around the Lake Tahoe basin. As of this writing on March 1† the Truckee River watershed stood at 141% of average precipitation and Lake Tahoe at 136% of average. Lake Tahoe rose over a foot during February, much of it from precipitation directly on its surface. If the Sierra and western Nevada continue to receive average snow and rainfall during March, there will be continued above average flows in rivers and streams in California and Nevada.
Other Nevada river basins also are currently above average††: Carson River basin, 120%; Walker River basin, 136%; Humboldt River basin, 115-117%. Likewise, the runoff forecast for the Colorado River has improved with additional precipitation in the Rocky Mountains during February.
Lake Tahoe rise Jan-Feb’19
The remainder of the winter season will determine just how significant the runoff will be for the 2018-19 water year. A continuation of the wet weather will result in additional runoff to positively benefit the rivers and streams and terminal lakes of Nevada that were negatively affected by the dry winters from 2012 through 2016 and the overall dry conditions that prevailed in the western US since the beginning of the century.
† The water year runs from October 1 to September 30.
†† Percent of average is a floating value based on the historic average for a given date.
Peavine Mtn from Rancho San Rafael in Reno mid-February ’19