Lower Colorado River Basin Water and LHC
Lake Mead and Lake Powell - The Balancing Act
Without any offsetting cutbacks, we are approaching a shortage mark of a million acre-feet per year. That would be, roughly estimated, about 325 billion gallons of water or enough for about 4.46 million people to use around 200 gallons of water per day for one year. That’s our structural deficit in the Lower Colorado River Basin. When we combine that with the naturally declining shape of the reservoir system, we can deduce that elevation levels will erode faster and faster assuming all other conditions remain equal or on trend lines; conditions like weather and rainfall. Finally, some emerging research has shown indicators there could be more sedimentation in the system than previously thought. That, of course, would be yet another detraction from system storage capacity.
The U.S. Department of the Interior Bureau of Reclamation operates the hydropower output of the Western United States. Hydropower plants currently account for about 7% of the U.S. energy mixture. In Arizona, most of our electricity is generated by natural gas and nuclear energy. Hoover Dam produces about 4 billion kilowatt-hours per year (Reclamation U. B., 2018), enough for about 1.3 million people. Arizona uses about 18.9% while Nevada gets 23.3%, the Metropolitan Water District of Southern California gets 28.5%, Los Angeles gets 15.4%, and there are numerous smaller allocations.
It is important to keep in mind that should the lake fall to an elevation below the required level for generating electricity, we would be pulling those kilowatt hours out of the regional distribution system. That would create a requirement to import power. The long-term compensatory mechanism is filling in the capacity by building power generation infrastructure. If hydro-generated electricity from the Colorado River Dam system is compromised, some estimates would suggest consumers could be hit with 25% (or more) additional cost per kilowatt hour. Water shortages that reduce electricity generation capacity will translate to higher power costs.
The elevation in Lake Mead that triggers a federally declared shortage is 1,075 feet. A recent study (AMWUA, 2018) from the Bureau of Reclamation Boulder Canyon Operations Office shows that projecting 8.23 million acre-feet released from Powell in 2018 would leave Powell’s elevation above 3,575 feet and Lake Mead would be below 1,075 feet, this would be a trigger point and is projected to transpire in May of 2019, one month after a shortage declaration point in April, thereby postponing an actual shortage declaration until 2020, unless inflows more than offset expected losses.
2018 water year hydrology summary shows the unregulated inflow to Lake Powell was 4.76 maf, or about 44% of the average year based on a 30-year data set. Cumulative precipitation in the Upper Colorado River Basin was about 44% of average with snowpack at about 73% of average. Tributary inflow to Lake Mead was 27% of average from the Little Colorado River and about 51% of average from the Virgin river. The Colorado River total system experienced a net decrease of 4.51 maf (Reclamation U. D., 2018) during the water year to date.
Careful management of water release while balancing the requirements of electricity generation mean the Bureau of Land Management (BLM) is engaged in strategic shifting or balancing of the lakes that allow them to operate within the scope of their requirements and hopefully, engage in a profile of operations that maximize electricity generation potential while mitigating and postponing a federally declared shortage.
A shortage declaration is governed by a set of Bureau of Reclamation (BOR) regulations known as the 2007 interim guidelines. The guidelines include key factors used when determining the declaration of shortage. The 2007 interim guidelines are part of a record of decision (ROD) concerning Colorado River interim guidelines for lower basin shortages and coordinated operations for Lake Powell and Lake Mead. (Department of the Interior, 2018)
Lake Havasu City Ramifications
It seems probable, all else equal, that a shortage declaration is likely to take place in 2020 unless inflows into the overall system are well above normal. BOR publishes 24-month studies, these are studies done each month and rolled up to create a 2-year view. Recent 24-month studies show the structural deficit being stressed by continued drought conditions. If drought conditions remain like those we have seen in the last 24-month period, a federally declared shortage could be declared for 2020. If that transpires, there will be cutbacks to priority 4 water in Arizona.Precipitation models continue to disappoint, and while there is some hope for El Niño to bring higher than normal precipitation, the impacts of climate change may more than offset any potential El Niño impact due to an extended growth season for deciduous plant life throughout the Upper Colorado River Basin. While it is possible precipitation may increase somewhat, predictive models show the extended season and higher temperatures impact upon vegetation use of moisture would more than offset increased precipitation. Warmer temperatures and a longer warm season will exacerbate drought conditions whenever precipitation levels fall below normal; all of which is consistent with recent trends. All which compounds to create a growing water deficit.
Lake Havasu secures 100% of its drinking water from the Colorado River by way of surface allocation. Currently, the City of Lake Havasu has rights to approximately 29,000 acre-feet of water per year, we are using less than half that amount or somewhere between 13,000 and 14,000 acre-feet. Our current allocation of water should provide adequate water use for a population roughly twice our size. This is an amazing position to be in because even if there were, for instance, a cut back of deliveries based on entitlements, our excess easily absorbs any intermediate range cutbacks.
Lake Havasu City Water Profile
Drinking water is drawn from a Ranney well that has a production capacity of about 26 million gallons per day (mgd). The Ranney well is essentially a large diameter vertical well with numerous horizontal arms extending into a porous formation immediately under the floor of the lake. This creates a natural filtration system for the water as it is drawn into the Ranney well, and from there it is delivered to the water plant for processing.The city maintains some 483 miles of water distribution lines that range from 36” down to 4” and serves over 31,000 residential and commercial water service points. The city maintains twenty-six tanks throughout seven pressure zones ranging from the highest elevations in the city down towards the lowest areas leveraging gravity to assist in managing pressure zones in optimal states and using lift stations where gravity is insufficient for operational requirements.
The city’s water infrastructure requires ongoing maintenance and water quality testing. The two capital intensive items to consider in forward budgeting are a secondary water supply, meaning a second Ranney well or the consideration of drilling horizontal wells under the lake, in a similar fashion to the current Ranney well. There may be some existing vertical wells where modifications may be leveraged to create horizontal access and/or new wells. I expect the cost (and risk) would be spread out across several vertical to horizontal wells enough to extend capacity during a complete shut-in event of the primary Ranney well.
The city does need a robust backup system, so we can have full cutover capability in order to take the Ranney well completely offline should that be required for maintenance needs. The cost to set up parallel production capacity that approximates our current system is going to be significant, this is part of our budget planning for water infrastructure. Accurate budget holders will depend on project timelines, capacity, abandonment costs, and the myriad of expenses associated with access, licensure, environmental, and reclamation.
I believe it is unlikely that any new ROD, or even an adjustment of the existing 2007 Interim Guidelines will bypass the intent or structure of the existing federal guidelines. In other words, there will be no major initiatives to create new “Acts of Congress” to deal with this. Instead, this is a process that has been ongoing with the U.S. Department of the Interior in the driver’s seat.
The State of Arizona currently has a steering committee that is meeting to cover areas where water conservation can be leveraged. Negotiations surrounding intentionally created surplus management will be an important part of the 2019 operating plan. Our hopes are to leverage what we must to facilitate the best outcome for the region while maintaining our full allotment of water rights.
Dealing with minor cutbacks to our full allotment would, essentially, be inconsequential and rightfully so, the city has done amazing work with conservation and getting average consumption per person almost halved since conservation efforts started many years ago. Having water allocation cutbacks drawn up based on actual use would be very different. It would be seen as a functional cap on the region population level. So far, we are not aware of any precedence in any of the legal agreements, acts, or other governing instruments that can be leveraged in such a manner as to drive cutbacks upon stated current use versus full allotment. Further, California, having a vast holding of 1st priority rights, is now starting to be more open to a dialogue of water conservation as a mechanism to limit their withdrawals.
California understands that if we drive the level of the lakes down far enough, to the point where it becomes dead storage at 895 feet, they’ll go below the level where we can release any water at all. At that point, California would have lots of priority 1 water rights, but no ability to draw any water. The states duly impacted by a federal shortage will be able to negotiate under the already established guidelines and acts but going outside of that to establish entirely new government policy at the federal level is not likely to happen on the time frame being considered. Therefore, I believe our water supply is in good shape, that we should continue to invest in monitoring and defending the principle of keeping mainstream water on the Colorado River and preventing it from being creatively liberated from our groundwater supplies through programs such as fallowing.
NASA Gravity Recovery and Climate Experiment mission (GRACE) created a nine-year slice of data analyzed for the Colorado River System; it showed groundwater accounted for 50.1 km3 of the total 64.8 km3 of freshwater loss. Groundwater is being depleted as a vastly greater rate than surface water and may impact our ability to continue to meet scheduled deliveries. This is the data, I’m afraid, I do not hear people discussing. But this data is real and I am concerned it may be even more important than the dropping levels of Lake Mead; yet it appears most of the stakeholders are blissfully unaware of the GRACE Mission data. At the very least, the rate of groundwater depletion will exacerbate the water shortage in the basin.
The Bigger Picture for Regional Water
Unfortunately, the larger picture is that climate change is likely to have a net negative impact on the water situation for Arizona. If we continue to exacerbate the drought without seeing Lake Mead and Lake Powell start to rise again, then we are in for a fast acceleration through our shortage levels. The main reason for that is twofold… the first is obvious, yet almost entirely overlooked. We think of the surface of either lake, but the lake is a reservoir, and to really understand the volumes, one must think of what it is like as a vessel.
The above image shows a view that brings the matter of volume into clear focus. In addition, new research is emerging from Lake Havasu City insomuch as a recent underwater mapping project has revealed more sedimentary deposits than are currently used with widespread existing modeling data, thus creating some potential that certain volume assumptions may be somewhat overstated. It is thought this might apply beyond Lake Havasu; and thus render a larger impact on the entire system.
Lake Havasu City's Priority 4 (P4) Water Rights are roughly outlined below. For reference, we use about 13,000 to 14,000 acre feet per year (estimated 2017) and we have over 28,000 acre feet authorized. Even with cutbacks to those allocations, we would still have an excess of water rights over water useage, and that's how the hottest city in the nation manages to have enough water during an extended drought. And of course, Lake Havasu City has extensive conservation efforts that have paid huge dividends over the years.
The Law of the River
The law of the river is not one set of codified articles set about in some leather-bound book on the shelves of fancy law offices. Instead, it is a mixture of various acts, key legal decisions, compacts, plans, traditions, and treaties; there is also a historical context.The Secretary of the Interior, through the Bureau of Reclamation, is responsible for water management throughout the United States. The Bureau of Reclamation’s authority is limited throughout the western United States by various reclamation instruments and acts of Congress.
Acts of Congress
- Reclamation Act of 1902
- Boulder Canyon Project Act of 1928
- The Colorado River Storage Project Act
- Colorado River Storage Act 1956
- Colorado River Basin Act of 1968
- Grand Canyon Protection Act of 1992
Key Legal Decisions / Compacts / Treaties
- US Supreme Court, Arizona vs. California 1963
- US Supreme Court Consolidated Decree, Arizona vs. California 2006
- Colorado River Compact 1992
- Upper Colorado River Basin Compact 1948
- Mexican Water Treaty 1944
- Key Information Points on Shortage Declarations 2007 Interim Guidelines
- The 2007 Record of Decision creating the 2007 Interim Guidelines - ROD expires 2026
Annual Operating Plan
Section 602(b) of the CRBPA of 1968 requires that the Secretary transmit to the Congress and to the Governors of the Basin States, by January 1st of each year, a report describing the actual operation under the LROC for the preceding compact water year and the projected operation for the current year. This report is commonly referred to as the “Annual Operating Plan” or the “AOP.” In 1992, in the Grand Canyon Protection Act, Congress required that, in preparing the 602(b) AOP, the Secretary shall consult with the Governors of the Basin States and with the general public, including representatives of academic and scientific communities, environmental organizations, the recreation industry; and contractors for the purpose of federal power produced at Glen Canyon Dam.24 Month Study - April Adjustment
April adjustments to Lake Powell operations in the Upper Elevation Balancing Tier (as specified in Sections 6.B.3. and 6.B.4.) shall be based on the April 24 Month Study projections of the September 30 system storage and reservoir water surface elevations for the current Water Year. Any such adjustments shall not require re-initiation of the AOP consultation process. In making these projections, the Secretary shall utilize the April 1 final forecast of the April through July runoff, currently provided by the National Weather Service’s Colorado Basin River Forecast Center.Off-stream Banking
The diversion of Colorado River water to underground storage facilities for use in subsequent Years from the facility used by a Contractor diverting such water
Key Definitions
Water Year
October 1st through September 30th24-Month Study
The projections are updated each month using the previous month’s reservoir contents and the latest inflow and water use forecasts. In these Guidelines, the term “projected on January 1” shall mean the projection of the January 1 reservoir contents provided by the 24-Month Study that is conducted in August of the previous Year.
Contractor
An entity holding an entitlement to Mainstream water under (a) the Consolidated Decree, (b) a water delivery contract with the United States through the Secretary, or (c) a reservation of water by the Secretary, whether the entitlement is obtained under (a), (b) or (c) before or after the adoption of these Guidelines.Direct Delivery Domestic Use
Direct delivery of water to domestic end users or other municipal and industrial water providers within the Contractor’s area of normal service, including incidental regulation of Colorado River water supplies within the Year of operation but not including Off-stream Banking. For the Metropolitan Water District of Southern California (MWD) Direct Delivery Domestic Use shall include delivery of water to end users within its area of normal service, incidental regulation of Colorado River water supplies within the Year of operation, and Off-stream Banking only with water delivered through the Colorado River Aqueduct.
Intentionally Created Surplus (ICS)
Surplus Colorado River System water available for use under the terms and conditions of a Delivery Agreement, a Forbearance Agreement, and these Guidelines.
Current Status
Lake Mead Elevation Projections
Precipitation (October 2017 – June 2018) The bulk of the entire Colorado River basin, both lower and upper, has received at least 30% less precipitation than average, this is exacerbated in the lower basin where many areas are experiencing less than half the average precipitation. While there is some potential for a return of the El Niño weather pattern, the impact that may have on precipitation in the Colorado River Basin may be negligible.
The National Weather Service (NWS) Climate Prediction Center, of the National Oceanic and Atmospheric Administration, as of September 13th, 2018, is predicting a 50-55% chance of an El Niño onset in the Northern Hemisphere in the September to October timeframe, increasing to a 65-70% chance of an El Niño during the winter months. The October 2017 to June 2018 precipitation map shows severe shortages over the clear majority of the Colorado River Basin with only a handful of areas in Northern Colorado and Southern Wyoming experiencing average or slightly above average precipitation.
Colorado River Basin Precipitation (October 2017 to June 2018) – National Weather Service (NOAA)
The Bureau of Reclamation 24-month study provides data for operational guidelines. This includes a combined monthly/annual methodology to determine the annual release volume for Lake Powell. Methodology consists of a January 1 determination of the release volume with appropriate April adjustments to those volumes in order to provide necessary flexibility to respond to changing inflow forecasts while ensuring that the operation does not result in excessive changes in monthly releases from Lake Powell.
April adjustments to Lake Powell operations in the Upper Elevation Balancing Tier (as specified in Sections 6.B.3. and 6.B.4.) shall be based on the April 24-Month Study projections of the September 30 system storage and reservoir water surface elevations for the current Water Year. Any such adjustments shall not require re-initiation of the AOP consultation process. In making these projections, the Secretary shall utilize the April 1 final forecast of the April through July runoff, currently provided by the National Weather Service’s Colorado Basin River Forecast Center, which is a monthly study on a 24-month cycle.
2007 Interim Guideline Definitions Normal Condition A “Normal Condition” exists when the Secretary determines that sufficient mainstream water is available to satisfy 7.5 million acre-feet (maf) of annual consumptive use in the Lower Division states (Arizona, California, and Nevada). If a state will not use all of its apportioned water for the year, the Secretary may allow other states of the Lower Division to use the unused apportionment, provided that the use is authorized by a water delivery contract with the Secretary.
Surplus Condition A “Surplus Condition” exists when the Secretary determines that sufficient mainstream water is available for release to satisfy consumptive use in the Lower Division states in excess of 7.5 maf annually. The water available for excess consumptive use is surplus and is distributed for use in Arizona, California, and Nevada pursuant to the terms and conditions provided in the ISG. The current provisions of the ISG are scheduled to terminate in 2016. In general terms, the ISG link the availability of surplus water to the elevation of Lake Mead. When Lake Mead is full and Reclamation is making flood control releases, surplus supplies are unlimited. As Lake Mead’s elevation drops, surplus water amounts are reduced, and ultimately eliminated. The ISG also link surplus availability to continued progress by California in reducing its agricultural use of water to benchmarks established in the ISG. If a state does not use all of its apportioned water for the year, the Secretary may allow other Lower Division states to use the unused apportionment, provided that the use is authorized by a water delivery contract with the Secretary.
Shortage Condition A “Shortage Condition” exists when the Secretary determines that insufficient mainstream water is available to satisfy 7.5 maf of annual consumptive use in the Lower Division states. To date, the Secretary has never made such a Interim Guidelines for the Operation of Lake Powell and Lake Mead December 2007 6 ROD - Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead determination, as flow in the Colorado River has been sufficient to meet Normal or Surplus delivery amounts. When making a shortage determination, the Secretary must consult with various parties as set forth in the Consolidated Decree and consider all relevant factors as specified in the LROC, including 1944 Treaty obligations, the priorities set forth in the Consolidated Decree, and the reasonable consumptive use requirements of mainstream water users in the Lower Division states. If a state does not use all of its apportioned water for the year, the Secretary may allow other Lower Division states to use the unused apportionment, provided that the use is authorized by a water delivery contract with the Secretary.
Lake Mead Shortage Triggers Policy and interim guidelines were brought forward in 2007 that remain applicable.
kaf = thousand acre-feet
maf = million acre-feet
1,075 feet = cutback of 400 kaf
1,050 feet = cutback of 500 kaf
1,025 feet = cutback of 600 kaf
Shortage Rules - Lake Mead
Below 1,075
In years when Lake Mead content is projected to be at or below elevation 1,075 feet and at or above 1,050 feet on January 1, a quantity of 7.167 maf shall be apportioned for consumptive use in the Lower Division States of which 2.48 maf shall be apportioned for use in Arizona and 287,000 af shall be apportioned for use in Nevada in accordance with the Arizona-Nevada Shortage Sharing Agreement dated February 9, 2007, and 4.4 maf shall be apportioned for use in California.
Below 1,050
In years when Lake Mead content is projected to be below elevation 1,050 feet and at or above 1,025 feet on January 1, a quantity of 7.083 maf shall be apportioned for consumptive use in the Lower Division States of which 2.4 maf shall be apportioned for use in Arizona and 283,000 af shall be apportioned for use in Nevada in accordance with the Arizona-Nevada Shortage Sharing Agreement dated February 9, 2007, and 4.4 maf shall be apportioned for use in California.
Below 1,025
In years when Lake Mead content is projected to be below elevation 1,025 feet on January 1, a quantity of 7.0 maf shall be apportioned for consumptive use in the Lower Division States of which 2.32 maf shall be apportioned for use in Arizona and 280,000 af shall be apportioned for use in Nevada in accordance with the Arizona-Nevada Shortage Sharing Agreement dated February 9, 2007, and 4.4 maf shall be apportioned for use in California. 2. During a Year when the Secretary has determined a Shortage Condition, the Secretary shall deliver Developed Shortage Supply available in a Contractor’s DSS Account at the request of the Contractor, subject to the provisions of Section 4.C. of the 2007 Interim Guidelines.Lake Powell Shortage Triggers
Shortage Criteria 2007 Interim Guidelines
When projections indicate Lake Powell’s elevation will be greater than 3,575 feet but Lake Mead would be lower than 1,075 feet, a short-term shortage would take effect. That impact would be felt by way of the reduction of 400,000 acre-feet per year. Beyond that, the numbers are set at 500,000 acre-feet at an elevation of 1,050 feet and 600,000 acre-feet when Lake Mead’s elevation drops to 1,025 feet.
Mohave County Power Generation & Misc. Water Use Data Points
2015 Mohave County Generated 3,839.25 gigawatt hours
2015 Tucson 80 gallons per capita per day (GPCD)
2015 US Average 83 GPCD
2015 Arizona Average 146 GPCD
2015 New Mexico and Texas 81 GPCD (lowest in US)
2015 Idaho 186 GPCD (highest in US)
Structural Deficit
Rebalancing Lake Mead & Lake Powell Policy and interim guidelines allow for rebalancing Lake Mead and Lake Powell for the remainder of 2018 by having additional releases from Lake Powell into Lake Mead. The conditions trigger a rebalancing that will release, from Lake Powell, not less than 8.23 million acre-feet and not greater than 9 million acre-feet. Lake Powell and Lake Mead, under the current circumstances, are projected to bypass the capacity for rebalancing activities in 2019 due to the structural imbalance build into the system. If shortage were declared, it would have distinct impacts, but most of the outcomes can be determined in advance through a careful examination of the policy, interim guidelines, and other negotiated arrangements that have been put forth amongst the various stakeholder groups, governments, and interested parties.
Current Status 2018-2019
Lake Powell end of August 2018 levels
Elevation for end of August 2018 was 3,597 feet (103 feet from full pool) and 11.2 maf (47 percent of full capacity). Average unregulated inflow was 8.76 maf, or 81percent of the 30-year average (1981-2010)
Lake Powell Projected 2019 Release to Lake Mead
The operating tier for water year 2019, established by the August 2018 24-Month Study, is the Upper Elevation Balancing Tier. Under this Tier the initial annual water year release volume is 8.23 maf but there is potential for an April 2019 adjustment to equalization or balancing releases. Based on the current forecast, an April adjustment to balancing releases is projected and Lake Powell is currently projected to release 9.0 maf in water year 2019. This projection will be updated each month throughout the water year.
Lake Powell End of water year forecast 2019
US Bureau of Reclamation Projections indicate end of water year 2019 elevation and storage using the minimum and maximum probable inflow forecast are 3,566 feet (8.8 maf, 36 percent of capacity) and 3,648 feet (17.0 maf, 70 percent of capacity), respectively. Under these scenarios, there is a 10 percent chance that inflows will be higher, resulting in higher elevation and storage, and 10 percent chance that inflows will be lower, resulting in lower elevation and storage.
Metropolitan Water District (MWD) Forecast
While continued conservation by CAP could keep the lake at 1,075 and above through 2019, California’s future use of Mead water remains a big unknown with up to 175,000 to 200,000 acre-feet of water available for withdraw from California’s Metropolitan Water District (MWD). During the same period, the Central Arizona Project, with low priority water rights, hopes to conserve 180,000 acre-feet of river water this year, essentially creating a theoretical offset for the water planned for MWD use.
U.S. Bureau of Reclamation forecast
Results of 24 Month Study published in 2018 water year for water in the Colorado River anticipates declaration of a shortage in September 2019 in Lake Mead. That would trigger the reduced water releases from federal reservoirs in “lower basin” states including Nevada and Arizona.Colorado and other “upper basin” states Utah, Wyoming and New Mexico would face increased scrutiny of flows from headwaters into the Lake Powell reservoir. On Wednesday, Lake Powell measured 49 percent full and Lake Mead measured 38 percent full.
A primary goal of the CBS policy is to significantly reduce the probability of an involuntary, uncompensated shortage in excess of 500,000 acre-feet (the approximate level at which CAP deliveries would be reduced beyond that currently utilized for water banking). As shown in Figure 4, below, the probability of shortages exceeding 500,000 acre-feet is reduced to 5% or less through the entire modeled period under the CBS policy. By contrast, the probability of shortage under the baseline policy rapidly approaches 30% during this same period. Furthermore, as shown in Figure 5, below, the CBS policy reduces the probability of any involuntary shortage by approximately 20% over the next 20 years.
Rising Power Costs
The recent drought and decrease in power production at both Hoover Dam and Glen Canyon Dam point to the dramatic costs imposed by the loss of reservoir storage. If Lake Mead falls to 1050 feet, power rates will need to be increased to an approximate composite rate of 2.31 cents/kWh, which is a 44.3% increase over current rates. Replacement power purchases would be (depending on the user) 2.9 to 3.7 times the Hoover rate. In FY03, replacement power may have cost customers an additional $24 million (Department of the Interior, 2018).Arizona Cutbacks
The Central Arizona Project (CAP) will be subject to the largest cutbacks. Arizona is allocated 2.8 maf annually. Most of the cutbacks are expected to impact recharge programs in the Greater Phoenix and Tucson areas, but also agricultural water deliveries as well.Arizona Steering Committee
The Lower Basin Drought Contingency Plan ( (LDBCP, 2018) is a plan developed by Arizona, California, Nevada, and the United States to create additional contributions to Lake Mead from Arizona and Nevada, along with new contributions from California and the U.S. with incentives for additional storage in Lake Mead.Key points to conserve come from agricultural mitigation, tribal intentionally created surplus, Arizona conservation plans and excess water. Ultimately, the goal is to secure a joint resolution from the Arizona Legislature authorizing the Arizona Department of Water Resources Director to agree to the plan. Currently, the bulk of the first level of cutbacks would be borne by CAP water users.
Informational Agreements
- Delivery Agreement between the United States and Imperial Irrigation District (IID)
- Delivery Agreement between the United States and The Metropolitan Water District of Southern California (MWD)
- Delivery Agreement between the United States, Southern Nevada Water Authority (SNWA) and the Colorado River Commission of Nevada (CRCN)
- Funding and Construction of the Lower Colorado River Drop 2 Storage Reservoir Project Agreement among the United States, SNWA, and CRCN
- Lower Colorado River Basin Intentionally Created Surplus Forbearance Agreement among the Arizona Department of Water Resources, the Southern Nevada Water Authority, CRCN, the Palo Verde Irrigation District (PVID), IID, Coachella Valley Water District (CVWD), MWD, and the City of Needles
- California Agreement for the Creation and Delivery of Extraordinary Conservation Intentionally Created Surplus among the PVID, IID, CVWD, MWD and the City of Needles
Jet Propulsion Laboratory (JPL) Grace Satellite Mission
The extent of groundwater loss may pose a greater threat to the water supply of the western United States than previously thought. NASA's Gravity Recovery and Climate Experiment, also known as the GRACE satellite mission (NASA, 2018) was designed to track changes in mass of specific geological regions, including the Colorado River Basin. The gravitational variance is then analyzed with other data points to gain an estimate of sub-surface water loss.We have two major dilemmas that our Jet Propulsion Laboratory helps to solve through the GRACE satellite mission. First, due to the overlapping governmental responsibilities and spheres of influence, there is no consolidated framework to properly assess and track sub-surface water. In the instances where data does exist, it is incomplete. In short, it’s very hard to get accurate groundwater data from all the different constituencies in such a manner that it may effectively be used for evidence-based decisions.
The other major dilemma is that we really don’t know how much groundwater we have left simply because we do not know how much we started with nor do we have suitable data to declare, with confidence, what recharge rates may be. These dilemmas make it very challenging to quantify amalgamated groundwater resources with a high degree of accuracy.
Accounting for month over month changes in the estimated water mass allow us to make estimates of system wide depletion rates. Monthly measurements in the change in water mass from December 2004 to November 2013 revealed the overall Colorado River Basin lost nearly 53 million acre-feet (65 cubic kilometers) of freshwater, or approximately double the volume of Lake Mead. Of that depletion, more than three-quarters of the total, approximately 41 million acre-feet, was from groundwater (Middleton, 2017).
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Bibliography
AMWUA. (2018, 09 05). where-we-stand. Retrieved from Arizona Municipal Water Users Association AMWUA: http://www.amwua.org/where-we-stand/issues/colorado-riverstructural-deficit
Department of the Interior. (2018, 09 16). Colorado River Interim Guidelines (2007) for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead. Retrieved from US Bureau of Reclamation Lower Colorado Region, Programs and Strategies Record of Decision, December 2007: https://www.usbr.gov/lc/region/programs/strategies/RecordofDecision.pdf
Department of the Interior. (2018, 09 10). Conservation Before Shortage. Retrieved from U.S. Bureau of Reclamation: https://www.usbr.gov/lc/region/programs/strategies/alternatives/CBS2A.pdf
Famiglietti, S. L. (2014). Groundwater depletion during drought threatens future water security of the Colorado River Basin. Geophysical Research Letters, 41(16).
LDBCP. (2018, 09 10). Lower Basin Drought Contingency Plan Steering Committee. Retrieved from Arizona Department of Water Resources: https://new.azwater.gov/sites/default/files/media/LBDCP_Steering_Committee_Roster _8.28.pdf
Middleton, K. E. (2017). Global Sensitivity of Simulated Water Balance Indicators Under Future Climate Change in the Colorado Basin. Water Resources Research.
NASA. (2018, 09 10). Parched West Is Using Up Underground Water: NASA/UCI. Retrieved from Jet Propulsion Laboratory: https://www.jpl.nasa.gov/news/news.php?feature=4229
Reclamation, U. B. (2018, 10 01). FAQ Page. Retrieved from Reclamation Managing Water in the West: https://www.usbr.gov/lc/region/pao/faq.html
Reclamation, U. D. (2018, 10 01). Draft AOP 2019 third consultation. Retrieved from Bureau of Reclamation: https://www.usbr.gov/uc/water/rsvrs/ops/aop/AOP19_Third_Consultation_draft.pdf
