Tag Archive for: Climate Change

States Have Started Negotiating New Rules to Keep the Colorado River From Crashing. Here’s What They Want

The states that share the Colorado River need to negotiate new rules to better manage the dwindling river so it can continue to meet the needs of millions of people across the Southwest. That means finding ways to keep more water in the river and reservoirs, which means less water to go around.

The high-stakes, multi-year negotiation process between the states — Colorado, Utah, Wyoming and New Mexico in the upper basin and Arizona, Nevada and California in the lower basin — along with the U.S. Bureau of Reclamation, officially kicked off in June.

By the start of 2027, the states and the federal government are expected to have a new agreement on rules to manage the river so that Lake Mead and Lake Powell, the country’s largest reservoirs, don’t hit critically low levels. Climate change and overuse have stressed the river system and helped drive both reservoirs to drop to record-low water levels.

Central Valley Farmers Are Having a Climate Reckoning

Climate change — and changing political winds — are prompting shifts in strategy at California’s largest agricultural water district.

Westlands Water District, which occupies some 1,100 square miles of the arid San Joaquin Valley, is in the midst of an internal power struggle that will determine how water fights unfold across the state.

Reclamation Announces 2024 Operating Conditions for Lake Powell and Lake Mead

The Bureau of Reclamation on August 15, released the Colorado River Basin August 2023 24-Month Study, which determines the tiers for the coordinated operation of Lake Powell and Lake Mead for 2024. These operating conditions, which are based on existing agreements under the 2007 guidelines and lower basin Drought Contingency Plans, will be in effect until the near-term guidelines from the Supplemental Environmental Impact Statement (SEIS) are finalized. Reclamation is currently analyzing the consensus-based Lower Division States proposed alternative for the SEIS.

Based on projections in the 24-Month Study, Lake Powell will operate in a Mid-Elevation Release Tier with a 7.48 million acre-feet release in water year 2024. Consistent with existing agreements, Lake Mead will operate in a Level 1 Shortage Condition – an improvement from the Level 2 Shortage Condition announced last year – with required shortages by Arizona and Nevada, coupled with Lower Basin Drought Contingency Plan water savings contributions. Mexico’s water delivery will be reduced consistent with Minute 323.

Western States Will Not Lose as Much Colorado River Water in 2024, Despite Long-Term Challenges

Federal officials said Tuesday they will ease water cuts for Western states reliant on the Colorado River in 2024, thanks to a slightly improved outlook, but long-term challenges remain.

The river serves seven U.S. states, Native American tribes and two states in Mexico. It also supports a multibillion-dollar farm industry in the West and generates hydropower used across the region. Years of overuse by farms and cities, and the effects of drought worsened by climate change has meant much less water flows today through the Colorado River than in previous decades.

The U.S. government announces water availability for the coming year months in advance so that cities, farmers and others can plan. The first mandatory cuts that magnified the crisis on the river went into effect in 2022, followed by even deeper cuts this year due to drought, poor precipitation and less runoff from the headwaters in the Rocky Mountains.

Conservation measures and a wetter winter have improved the river’s health, leading to cuts being dialed back, starting in January. It won’t lead to dramatic changes because those affected have been living with water cuts for two years — or are voluntarily conserving water.

Lake Mead-Lake Powell-Colorado River Basin-U.S. Bureau of Reclamation

Reclamation Announces 2024 Operating Conditions for Lake Powell and Lake Mead

The Bureau of Reclamation on August 15, released the Colorado River Basin August 2023 24-Month Study, which determines the tiers for the coordinated operation of Lake Powell and Lake Mead for 2024. These operating conditions, which are based on existing agreements under the 2007 guidelines and lower basin Drought Contingency Plans, will be in effect until the near-term guidelines from the Supplemental Environmental Impact Statement (SEIS) are finalized. Reclamation is currently analyzing the consensus-based Lower Division States proposed alternative for the SEIS.

Based on projections in the 24-Month Study, Lake Powell will operate in a Mid-Elevation Release Tier with a 7.48 million acre-feet release in water year 2024. Consistent with existing agreements, Lake Mead will operate in a Level 1 Shortage Condition – an improvement from the Level 2 Shortage Condition announced last year – with required shortages by Arizona and Nevada, coupled with Lower Basin Drought Contingency Plan water savings contributions. Mexico’s water delivery will be reduced consistent with Minute 323.

Lake Mead’s release in 2023 is projected to be the lowest in 30 years, approximately one and half million acre-feet lower than an average normal year, reflecting extensive, ongoing conservation efforts in the Lower Basin states funded in part by President Biden’s historic Investing in America agenda, above-normal inflows in the lower basin below Hoover Dam, and conservation in Mexico.

Reclamation: Significant improvement for Lake Mead due to improved hydrology, ongoing conservation efforts. Operating guidelines in effect until Reclamation finalizes SEIS, including analysis of consensus-based state conservation agreement.

Investments in system conservation and improved hydrology this year have provided an opportunity to recover some reservoir storage. At the same time, the Colorado River system continues to face low elevations, with Lake Powell and Lake Mead at a combined storage of 36%.

“The above-average precipitation this year was a welcome relief, and coupled with our hard work for system conservation, we have the time to focus on the long-term sustainability solutions needed in the Colorado River Basin. However, Lake Powell and Lake Mead – the two largest reservoirs in the United States and the two largest storage units in the Colorado River system – remain at historically low levels,” said Reclamation Commissioner Camille Calimlim Touton. “As we experience a warmer, drier west due to a prolonged drought, accelerated by climate change, Reclamation is committed to leading inclusive and transparent efforts to develop the next-generation framework for managing the river system.”

Reclamation on Development of Near- and Long-Term Guidelines

Reclamation is simultaneously developing both near- and long-term guidelines for Lake Powell and Lake Mead operations. The supplemental SEIS in progress focuses on near-term actions, which would be applicable from 2024 through 2026 based on potential changes to limited sections of the 2007 Interim Guidelines. Reclamation temporarily withdrew the SEIS so it could fully analyze the consensus-based Lower Division States proposed alternative and will publish an updated draft SEIS for public review and comment with the consensus-based proposal as an action alternative later this year.

In addition to several agreements that have already been finalized, a consensus-based proposal – agreed upon by the three Lower Basin states earlier this year – commits to measures to conserve at least 3 million-acre-feet (maf) of system water through the end of 2026, when the current operating guidelines are set to expire.

The long-term guidelines, informally referred to as Post 2026 Operations, will revisit the 2007 Interim Guidelines in full, as well as other operating agreements that expire in 2026, including Drought Contingency Plans and Minute 323. In June, Reclamation initiated the formal process to develop the long-term operating guidelines.

Reclamation is committed to an inclusive and transparent process that enhances meaningful Tribal engagement as well as collaboration with all stakeholders in the basin. In response to Tribal feedback, the Department of the Interior established the first-ever Federal-Tribal-State partnership to promote equitable information-sharing and discussion among the sovereign governments in the Colorado River Basin. All 30 Colorado River Basin Tribal Nations and the seven U.S. basin states were invited to participate in this new group. The group met for the first time last week with Deputy Secretary Tommy Beaudreau, Commissioner Touton, and other Department leaders. The formation of this new group does not replace any independent consultation with either Tribes or states.

2024 Operations of Lake Powell and Lake Mead

Until the updated near-term guidelines are finalized once the supplemental SEIS is complete, Reclamation will continue to implement the plans developed over the past two decades that lay out detailed operational rules for these critical Colorado River reservoirs through 2026:

  • Lake Powell Mid-Elevation Release Tier: The 24-Month Study, with an 8.23 maf release pattern in October – December 2023, projects Lake Powell’s January 1, 2024, elevation to be 3,568.57 feet – about 130 feet below full and about 80 feet above minimum power pool. Based on this projection, Lake Powell will operate in the Mid-Elevation Release Tier in water year 2024 (October 1, 2023, through September 30, 2024). Under this tier, Lake Powell will release 7.48 million acre-feet in water year 2024 without the potential for a mid-year adjustment in April 2024. Under the most probable scenario, and with a 7.48 maf release pattern in October – December 2023, Lake Powell’s projected elevation on January 1, 2024, is 3,573.68 feet.
  • Lake Mead Level 1 Shortage Condition: The 24-Month Study projects Lake Mead’s January 1, 2024, elevation to be 1,065.27 feet – about 10 feet below the Lower Basin shortage determination trigger of 1,075 feet and about 25 feet below the drought contingency plan trigger of 1,090 feet. This elevation is based on a 7.48 maf release from Lake Powell in water year 2024. Based on this projection, Lake Mead will operate in a Level 1 Shortage Condition for calendar year 2024 (January 1, 2024, through December 31, 2024). This is a significant improvement from the Level 2 Shortage Condition announced last year. The required shortage reductions and water savings contributions under the 2007 Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations of Lake Powell and Lake Mead, 2019 Lower Basin Drought Contingency Plan and Minute 323 to the 1944 Water Treaty with Mexico are:
    • Arizona:  512,000 acre-feet, which is approximately 18% of the state’s annual apportionment.
    • Nevada:  21,000 acre-feet, which is 7% of the state’s annual apportionment.
    • Mexico:  80,000 acre-feet, which is approximately 5% of the country’s annual allotment.

Lower Basin projections for Lake Mead include updated water orders to reflect additional conservation efforts and new completed system conservation agreements under the Lower Colorado River Basin System Conservation and Efficiency Program.

President Biden’s Investing in America Agenda

System conservation and efficiency programs in the Colorado River Basin are being strengthened by President Biden’s Investing in America agenda and will invest in long-term durable system efficiency improvements that result in quantifiable, verifiable water savings in the Basin.

The Investing in America agenda represents the largest investment in climate resilience in the nation’s history and is providing much-needed resources to enhance Western communities’ resilience to drought and climate change, including protecting the short- and long-term sustainability of the Colorado River System. Through the Bipartisan Infrastructure Law, Reclamation is investing a total of $8.3 billion over five years for water infrastructure projects, including water purification and reuse, water storage and conveyance, desalination and dam safety. The Inflation Reduction Act is investing an additional $4.6 billion to address the historic drought.

To date, the Interior Department has announced the following investments for Colorado River Basin states, which will yield hundreds of thousands of acre-feet of water savings each year once these projects are complete:

Opinion: How Bad the Climate Crisis Gets is Still Up to Us. We Just Have to Act

As usual, California was ahead of the game. It’s been two decades since lawmakers passed the first law to begin requiring electric utilities to replace fossil fuels with renewable energy. Nearly as long since Gov. Arnold Schwarzenegger called for 1 million solar roofs. A decade since the state first mandated large numbers of electric cars on the road, and four years since Berkeley became the first U.S. city to ban gas appliances in new homes.

Opinion: Say Goodbye to Grass That’s Only There for Looks. California Can’t Afford to Waste Water

California was so dry and its water supply so precarious by May 2022 that the State Water Resources Control Board issued an emergency order: No drinkable water could be used to irrigate grass that had no function other than to look nice.

The regulation does not apply to residential lawns, although they were already turning brown due to local restrictions on sprinkler use.

It does apply to all purely ornamental lawns — “nonfunctional turf,” in regulatory parlance — at commercial, industrial and institutional sites, such as shopping centers and corporate headquarters.

That order was recently extended for another year.

It’s time for California to follow Nevada’s lead and permanently remove decorative turf.

To be clear, we’re talking only about nonfunctional turf. That means grass that no one walks on, except to mow it. It doesn’t apply to playing fields, picnic grounds, parks, meeting areas, schools, cemeteries or any place where people gather, play, loll, visit or frolic. It won’t keep anyone from feeling wet grass under their bare toes. Instead, think fenced areas with “keep off the grass” signs, plus street medians, mall landscaping and the like.

 

(Editor’s Note: For rebates, classes, and water-saving tips: sdcwa.org/your-water/conservation/.)

How Much Water is Left in the Colorado River? Scientists and Officials are Scrambling to Find Out

Fresh off a phenomenal winter snowpack, water levels on the Colorado River are going up for the first time in years.

As a result, federal officials will announce this week that they are easing water restrictions in the Southwest starting next year, three sources familiar with the plan told CNN, lifting the region from a Tier 2 water shortage to a Tier 1. It’s a remarkable turnaround that will give back billions of gallons of Colorado River water to millions of people in the Southwest, primarily in Arizona and Nevada.

But they can’t breathe a sigh of relief. Officials, farmers and tribes are bracing for more difficult negotiations on how to divvy up the river when the current interstate agreement expires in 2026.

Warming is Shifting Napa’s Wine Growing Season

The start of wine grape growing season in California’s Napa Valley now comes nearly a month earlier than it used to because of the region’s warming climate, according to a new study from a team led by UC San Diego Scripps Institution of Oceanography researcher Dan Cayan.

The research, published online in the International Journal of Climatology on June 29, is based on an analysis of local temperature records spanning 1958-2016 that charts the effects of natural climate variations such as the Pacific Decadal Oscillation and the growing influence of human-caused climate change upon the seasonal rhythms and shorter term temperature extremes in Napa Valley.

wine growing season-UCSD-Scripps-Napa Valley

Warming is Shifting Napa’s Wine Growing Season

The start of wine grape growing season in California’s Napa Valley now comes nearly a month earlier than it used to because of the region’s warming climate, according to a new study from a team led by UC San Diego Scripps Institution of Oceanography researcher Dan Cayan.

The research, published online in the International Journal of Climatology on June 29, is based on an analysis of local temperature records spanning 1958-2016 that charts the effects of natural climate variations such as the Pacific Decadal Oscillation and the growing influence of human-caused climate change upon the seasonal rhythms and shorter term temperature extremes in Napa Valley.

Since 2006, Cayan has been working with the Napa Valley Vintners trade association, which funded the new research along with additional support from the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), to help Napa vintners understand the effects of climate variation and change on their region and on their renowned premium grapevines.

“The vintners want to know what’s changing and what the nature of those changes is,” said Cayan.

In a 2011 report, Cayan showed that Napa had warmed by 1-2 degrees Fahrenheit since the 1930s — markedly less than the 3 degrees of warming suggested by earlier studies. Cayan and his team found then that the magnitude of warming in Napa is difficult to pin down exactly, and different temperature records and ways of treating them result in a substantial range in estimated temperature trends. The team took great pains to identify temperature records that most correctly captured Napa’s unique climate, which is affected both by cooler maritime influences and inland heat.

Temperature variation and change

The present study takes another look at Napa’s temperature variation and change, adding seven years of more recent data. It also takes a sharper aim at factors that are particularly important to Napa’s viticulture, translating the decades of temperature observations into a set of key wine-growing metrics. The goal, said Cayan, was to use this lengthy temperature record to examine the implications of the last six decades of temperature variation and change for Napa Valley vineyard growers and wine producers.

The researchers assembled their temperature data largely from observations taken at the Napa State Hospital. Cayan said the hospital’s location makes it an imperfect representation of weather conditions in Napa. It is close to roads and buildings which can influence temperature readings, but this weather station has been in place for several decades and biases introduced by the surroundings have likely been consistent. NOAA has also deemed the temperature record from the hospital reliable enough to use it as one the data sources for its national and regional scale climate monitoring in the United States.

The researchers filled in any missing data using other sources, such as the weather records from a weather station in Oakville, California managed by the state’s Department of Water Resources, and performed other quality control steps to ensure the data were as reliable as possible.

“Wine grapes offer a super interesting lens through which we can view climate variation,” said Cayan, noting the many ways temperature impacts grape growth and wine quality.

Using the Napa daily temperature records, the team developed and analyzed variations and changes in several temperature-dependent metrics of importance to wine grapes. Key among these metrics was the beginning of the growing season, which was defined as the time when the average daily temperature rises in spring to consistently exceed 50 degrees Fahrenheit.

The study also looked at the time required to bring wine grapes to maturity. Other measures included the occurrence of extreme hot days that may be detrimental to grape quality, and the temperature during the final 45 days before grapes mature — a period that is vital in determining grapes’ sugar content and flavor.

Growing season starts four weeks earlier now than in 1950s

The study found that the growing season now starts more than four weeks earlier than it did in 1958. This means that in Napa back around 1958, average daily temperatures typically first exceeded 50 degrees Fahrenheit consistently around April 1. Fast forwarding to 2016, the study finds that the start of the growing season generally occurs around March 1.

For wine growers and makers this means that wine grapes will also generally mature about a month earlier than they used to in the late 1950s, but Cayan noted that the actual harvest date is more changeable, as some vintners may make stylistic choices to delay harvest.

“This is a remarkable long-term shift given that wine grapes require about six months to mature on the vine and most year-to-year fluctuations in growing season start were typically limited to about three weeks,” said Cayan.

Warmer conditions, earlier growing seasons

The average temperature of the last 45 days of the growing season also warmed by more than 3 degrees Fahrenheit during the study period.

“The Napa record indicates an undeniable shift towards earlier growing seasons and warmer conditions,” said Cayan. “The strongest changes took hold in the 1970s and warmed pretty dramatically through the 1990s, in sync with the large-scale North Pacific climate shift that commenced in the mid-1970s.”

The warming trend Cayan and his colleagues observed in Napa echoed changes seen elsewhere in the American West and Pacific Ocean. In recent decades, western North America has been one of the U.S. hot spots for warming, with about 2 degrees Fahrenheit of increase compared to 1950’s temperatures. Napa’s warming during that period was roughly equivalent.

Anthropogenic climate change

Additionally, anomalously warm temperatures persisted in recent decades despite the fact that a natural source of climatic variation called the Pacific Decadal Oscillation reverted to its cooler state.

“As numerous studies have demonstrated in other settings, these persistent changes strongly suggest that anthropogenic climate change is playing a role,” said Cayan.

Along with warmer seasonal average temperatures in recent decades, the Napa record has shown a significant reduction in the occurrence of cool extremes and an increased occurrence of warm extremes.

Global impacts of climate change

The advancing start of the wine grape growing season in Napa joins a body of research documenting how climate change has altered seasons across the globe, with the most direct comparison being the earlier start of spring.

“This is another piece of evidence of a remarkable seasonal change occurring across the western landscape and is very likely a signal that is being reinforced by climate change,” said Cayan.

However, Cayan was careful to note that the links between Napa’s warming climate and anthropogenic climate change inferred in this study’s results were correlational rather than causal.

“Regional temperature changes including those in Napa Valley are invariably affected by multiple natural drivers as well as human-caused warming effects,” said Cayan. “Teasing those influences apart would require an extensive climate modeling attribution science study that was beyond the scope of the present study.”

Climate challenges for Napa Valley wine growers

For winemakers in Napa banking on the continuation of their historically mild Mediterranean climate, Cayan said the results underscore that “climate changes are likely to drive Napa growers to continue to innovate, perhaps using novel growing practices, and perhaps by introducing grape varieties that might be more heat-tolerant.”

Further, the paper states that the continued anomalous warmth of the last seven years combined with projected further warming strongly suggests that an additional 1 degree Fahrenheit of warming is likely within the next three decades, along with more significant and more frequent bouts of extreme heat.

“Such an increase in heat would impose a challenge in producing premium quality wine,” wrote the study authors.

Rapidly warming climate

And Napa is not alone. Other regions with longer wine growing traditions, such as France or Italy, are already experiencing similar forks in the road when it comes to the continued viability of their chosen varieties and systems of agriculture in the face of rapidly warming climate.

Looking forward, Cayan suggested that California should take an even more fine-grained approach to anticipate the local effects of climate change, especially in regions with sensitive crops such as wine.

“A key issue for Napa is the extent to which its climate will be moderated by its marine layer air-conditioning and whether that can overcome the faster warming projected in nearby inland regions,” said Cayan. “We need more precise regional climate investigations to get a better handle on how changes in the coast-interior transition zones might unfold.”

Laurel DeHaan and Mary Tyree of Scripps Oceanography as well as sustainability scientist Kimberly Nicholas of Lund University were co-authors of the study.

(Editor’s Note: Story by Alex Fox, at UC San Diego Scripps Institution of Oceanography. The San Diego County Water Authority has partnered with the Scripps Institution of Oceanography at UC San Diego to better predict atmospheric rivers and improve water management before, during, and after those seasonal storms.)