U.S. Department of the Interior November 22, 2022

Er ye6.c 

Annual Operating Plan for 

Colorado River Reservoirs 

2023 

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i 2023 AOP – November 22, 2022

TABLE OF CONTENTS

INTRODUCTION ...................................................................................................... 1

Background........................................................................................................................ 1

Authority............................................................................................................................. 2

Purpose.............................................................................................................................. 3

Summary of Projected 2023 Operations............................................................................ 4

Upper Basin. .................................................................................................................. 4

Lower Basin. .................................................................................................................. 5

1944 United States-Mexico Water Treaty. ..................................................................... 6

BASINWIDE DROUGHT RESPONSE OPERATIONS............................................. 7

Upper Basin Drought Response Operations Agreement (DROA) ..................................... 7

2022 Powell Release Reduction; Operational Neutrality and Protection of the Glen 

Canyon Dam Facilities and Operations ............................................................................. 8

Lower Basin MOU – 500 Plus Plan.................................................................................... 9

Supplemental Environmental Impact Statement (SEIS) .................................................... 9

2022 HYDROLOGY SUMMARY AND RESERVOIR STATUS .............................. 10

2023 WATER SUPPLY ASSUMPTIONS ............................................................... 13

SUMMARY OF RESERVOIR OPERATIONS IN 2022 AND PROJECTED 2023 

RESERVOIR OPERATIONS.................................................................................. 15

Fontenelle Reservoir........................................................................................................16

Flaming Gorge Reservoir................................................................................................. 16

Blue Mesa, Morrow Point, and Crystal Reservoirs (Aspinall Unit) ...................................19

Navajo Reservoir .............................................................................................................20

Lake Powell......................................................................................................................21

2023 Operating Tier and Projected Operations for Glen Canyon Dam........................23

Lake Mead .......................................................................................................................25

Lake Mohave and Lake Havasu ......................................................................................26

Bill Williams River ............................................................................................................27

Senator Wash and Laguna Reservoirs ............................................................................27

Imperial Dam....................................................................................................................28

Gila River Flows...............................................................................................................28

Warren H. Brock Reservoir..............................................................................................28

Yuma Desalting Plant ......................................................................................................29

Off-stream Storage Agreements ......................................................................................29

Intentionally Created Surplus...........................................................................................29

Extraordinary Conservation ICS...................................................................................30

System Efficiency ICS.................................................................................................. 31

Tributary Conservation ICS..........................................................................................31

Imported ICS................................................................................................................31

Binational ICS. .............................................................................................................31

DCP ICS. .....................................................................................................................31

System Conservation.......................................................................................................32

Delivery of Water to Mexico .............................................................................................34

2023 DETERMINATIONS....................................................................................... 36

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ii 2023 AOP – November 22, 2022

Upper Basin .....................................................................................................................36

Lower Basin .....................................................................................................................37

1944 United States-Mexico Water Treaty ........................................................................40

DISCLAIMER ......................................................................................................... 41

ACRONYMS AND ABBREVIATIONS.................................................................... 42

LIST OF TABLES

Table 1. Reservoir Conditions on October 1, 2022 (English Units)..............................12

Table 2. Reservoir Conditions on October 1, 2022 (Metric Units)................................12

Table 3. Projected Unregulated Inflow into Lake Powell for Water Year 2023 (English 

Units)...........................................................................................................................14

Table 4. Projected Unregulated Inflow into Lake Powell for Water Year 2023 (Metric 

Units)...........................................................................................................................14

Table 5. Summary of Extraordinary Conservation ICS Plans of Creation...................31

Table 6. Summary of Projected System Conservation in the Lower Basin for 

Calendar Years 2022 and 2023..................................................................................33

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1 2023 AOP – November 22, 2022

INTRODUCTION

Background

Each year’s Annual Operating Plan (AOP) for Colorado River Reservoirs reports on both the 

past operations of the Colorado River reservoirs for the completed year as well as projected 

operations and releases from these reservoirs for the current (i.e., upcoming) year. 

Accordingly, this 2023 AOP reports on 2022 operations as well as projected operations for 

2023. In recent years, additions to the Law of the River such as operational rules, guidelines, 

and decisions have been put into place for Colorado River reservoirs including the 1996 Glen 

Canyon Dam Record of Decision1 (ROD), the Operating Criteria for Glen Canyon Dam,2 the 

1999 Off-stream Storage of Colorado River Water Rule (43 Code of Federal Regulations 

[CFR] Part 414),3

 the 2001 Interim Surplus Guidelines4 addressing operation of Hoover Dam, 

the 2006 Flaming Gorge Dam ROD,5 the 2006 Navajo Dam ROD6 to implement recommended 

flows for endangered fish, the 2007 Interim Guidelines for the operations of Lake Powell and 

Lake Mead,7 the 2012 Aspinall ROD,8 the 2016 Glen Canyon Dam Long-Term Experimental 

and Management Plan (LTEMP) ROD,

9

 Minute No. 323 between the United States and 

Mexican Sections of the International Boundary and Water Commission (IBWC),10 and the 

agreements related to the 2019 Colorado River Drought Contingency Plans (DCPs)11 as 

authorized by Public Law 116-14.12 Each AOP incorporates these and other rules, guidelines, 

1 ROD for the Operation of Glen Canyon Dam, October 9, 1996. Available online at: 

https://www.usbr.gov/uc/envdocs/rod/Oct1996_OperationGCD_ROD.pdf. 2

 Following the implementation of the LTEMP ROD, the Glen Canyon Dam operating criteria were revised and 

available online at: https://www.usbr.gov/uc/water/crsp/studies/GCOC.pdf. 3 Off-stream Storage of Colorado River Water; Development and Release of Intentionally Created Unused 

Apportionment in the Lower Division States: Final Rule (43 CFR Part 414; 64 Federal Register 59006, 

November 1, 1999). Available online at: https://www.usbr.gov/lc/region/g4000/contracts/FinalRule43cfr414.pdf. 4 ROD for the Colorado River Interim Surplus Guidelines, January 16, 2001 (67 Federal Register 7772, January 

25, 2001). Available online at: https://www.usbr.gov/lc/region/g4000/surplus/surplus_rod_final.pdf. 5 ROD for the Operation of Flaming Gorge Dam, February 16, 2006. Available online at: 

https://www.usbr.gov/uc/envdocs/rod/fgFEIS/final-ROD-15feb06.pdf. 6 ROD for Navajo Reservoir Operations, Navajo Unit – San Juan River, New Mexico, Colorado, Utah, July 31, 

2006. Available online at: https://www.usbr.gov/uc/envdocs/eis/navajo/pdfs/NavWaterOpsROD2006.pdf. 7 ROD for Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake 

Powell and Lake Mead (73 Federal Register 19873, April 11, 2008). The ROD adopting the 2007 Interim 

Guidelines was signed by the Secretary on December 13, 2007. Available online at: 

https://www.usbr.gov/lc/region/programs/strategies/RecordofDecision.pdf. 8 ROD for the Aspinall Unit Operations, Final Environmental Impact Statement, April 2012. Available online at: 

https://www.usbr.gov/uc/envdocs/eis/AspinallEIS/ROD.pdf. 9

 ROD for the Glen Canyon Dam Long-Term Experimental and Management Plan Final Environmental Impact 

Statement, December 2016. Available online at: http://ltempeis.anl.gov/documents/docs/LTEMP_ROD.pdf. 10 IBWC Minute No. 323, Extension of Cooperative Measures and Adoption of a Binational Water Scarcity 

Contingency Plan in the Colorado River Basin dated September 21, 2017. Available online at: 

https://www.ibwc.gov/Files/Minutes/Min323.pdf. 11 The agreements related to the 2019 Colorado River DCPs, as authorized by Public Law 116-14, were executed 

on May 20, 2019, and consist of an Upper Basin DCP (Drought Response Operations and Demand Management 

Storage) and a Lower Basin DCP including Lower Basin Drought Operations. Available online at: 

https://www.usbr.gov/dcp/finaldocs.html. 12 The Colorado River Drought Contingency Plan Authorization Act (Public Law 116-14) was signed into law on 

April 16, 2019. Available online at: https://www.congress.gov/116/bills/hr2030/BILLS-116hr2030enr.pdf.

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2 2023 AOP – November 22, 2022

and decisions, and reports on how the criteria contained in the applicable decision document or 

documents are implemented. Thus, the AOP makes projections and reports on how the Bureau 

of Reclamation (Reclamation) will implement these decisions in response to changing water 

supply conditions as they unfold during the upcoming year, when conditions become known. 

Congress has charged the Secretary of the Interior (Secretary) with stewardship and 

responsibility for a wide range of natural, cultural, recreational, and tribal resources within the 

Colorado River Basin. The Secretary has the authority to operate and maintain Reclamation 

facilities within the Colorado River Basin addressed in this AOP to help manage these 

resources and accomplish their protection and enhancement in a manner fully consistent with 

applicable provisions of Federal law including the Law of the River, applicable provisions of 

State law, and other project-specific operational limitations.

The Secretary recognized in the 2007 Interim Guidelines that the AOP provides an integrated 

report on reservoir operations affected by numerous federal policies: "The AOP is used to 

memorialize operational decisions that are made pursuant to individual federal actions (e.g., 

ISG [the 2001 Interim Surplus Guidelines], 1996 Glen Canyon Dam ROD, this [2007 Interim 

Guidelines] ROD). Thus, the AOP serves as a single, integrated reference document required 

by section 602(b) of the CRBPA of 1968 [Colorado River Basin Project Act of September 30, 

1968 (Public Law 90-537)]13 regarding past and anticipated operations." 

Authority

This 2023 AOP was developed in accordance with the processes set forth in: Section 602 of 

the CRBPA; the Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs 

Pursuant to the Colorado River Basin Project Act of September 30, 1968 (Public Law 90-537) 

(Operating Criteria), as amended, promulgated by the Secretary;14 and Section 1804(c)(3) of 

the Grand Canyon Protection Act of 1992 (Public Law 102-575).15 

Section 602(b) of the CRBPA requires the Secretary to prepare and “transmit to the Congress 

and to the Governors of the Colorado River Basin States a report describing the actual 

operation under the adopted criteria [i.e., the Operating Criteria] for the preceding compact 

water year and the projected operation for the current year.” 

This AOP has been developed consistent with: the Operating Criteria; applicable Federal laws; 

the Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande, the Treaty 

Between the United States of America and Mexico, signed February 3, 1944 (1944 United 

States-Mexico Water Treaty);16 interstate compacts; court decrees; the Colorado River Water 

Delivery Agreement;

17 the 2007 Interim Guidelines; the 2019 Colorado River DCP agreements; 

and other documents relating to the use of the waters of the Colorado River, which are 

13 Available online at: https://www.usbr.gov/lc/region/pao/pdfiles/crbproj.pdf. 14 Available online at: https://www.usbr.gov/lc/region/g4000/lroc/frmar2905.pdf. 15 Available online at: https://www.usbr.gov/uc/legal/gcpa1992.pdf. 16 Available online at: https://www.ibwc.gov/Files/1944Treaty.pdf. 17 Colorado River Water Delivery Agreement: Federal Quantification Settlement Agreement for Purposes of 

Section 5(B) of Interim Surplus Guidelines, October 10, 2003 (69 Federal Register 12202, March 15, 2004). 

Available online at: https://www.usbr.gov/lc/region/g4000/crwda/crwda.pdf. 

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3 2023 AOP – November 22, 2022

commonly and collectively known as the Law of the River. 

The 2023 AOP was prepared by Reclamation on behalf of the Secretary, working with other 

Interior agencies and the Western Area Power Administration (WAPA). Reclamation 

consulted with the seven Colorado River Basin States Governors’ representatives, 

representatives from Mexico, the Upper Colorado River Commission (UCRC), Native 

American tribes, other appropriate Federal agencies, representatives of academic and scientific 

communities, environmental organizations, representatives of the recreation industry, water 

delivery contractors, contractors for the purchase of Federal power, others interested in 

Colorado River operations, and the general public through the Colorado River Management 

Work Group.

Article I(2) of the Operating Criteria allows for revision of the projected plan of operation to 

reflect current hydrologic conditions with notification to the Congress and the Governors of the 

Colorado River Basin States of any changes by June of each year. The process for revision of 

the AOP is further described in Section 7.C of the 2007 Interim Guidelines. Any revision to 

the final AOP may occur only through the AOP consultation process as required by applicable 

Federal law.

Purpose

The purpose of the AOP is to report on the past year’s operations and illustrate the potential 

range of reservoir operations that might be expected in the upcoming year, and to determine or 

address: (1) the quantity of water considered necessary to be in storage in the Upper Basin 

reservoirs as of September 30, 2023, pursuant to Section 602(a) of the CRBPA; (2) water 

available for delivery pursuant to the 1944 United States-Mexico Water Treaty and Minutes 

No. 242,18 323, and 327,19 of the IBWC; (3) whether the reasonable consumptive use 

requirements of mainstream users in the Lower Division States will be met under a “Normal,” 

“Surplus,” or “Shortage” Condition as outlined in Article III of the Operating Criteria and as 

implemented by the 2007 Interim Guidelines; (4) whether management and/or operational 

regimes will be required or considered as described in the 2019 Colorado River DCPs; and (5) 

whether water apportioned to, but unused by one or more Lower Division States, exists and can 

be used to satisfy beneficial consumptive use requests of mainstream users in other Lower 

Division States as provided in the Consolidated Decree of the Supreme Court of the United 

States in Arizona v. California, 547 U.S. 150 (2006) (Consolidated Decree).20

Consistent with the above determinations and in accordance with other applicable provisions of 

the Law of the River, the AOP was developed with “appropriate consideration of the uses of 

the reservoirs for all purposes, including flood control, river regulation, beneficial consumptive 

uses, power production, water quality control, recreation, enhancement of fish and wildlife, and 

other environmental factors” (Operating Criteria, Article I(2)). 

18 IBWC Minute No. 242, Permanent and Definitive Solution to the International Problem of the Salinity of the 

Colorado River dated August 30, 1973. Available online at: https://www.ibwc.gov/Files/Minutes/Min242.pdf. 19 IBWC Minute No. 327, Emergency Deliveries of Colorado River Waters for use in the city of Tijuana, Baja 

California dated January 28, 2022. Available online at: https://www.ibwc.gov/Files/Minutes/Min327.pdf. 20 Available online at: https://www.usbr.gov/lc/region/pao/pdfiles/scconsolidateddecree2006.pdf. 

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4 2023 AOP – November 22, 2022

Since the hydrologic conditions of the Colorado River Basin can never be completely known in 

advance, the AOP presents projected operations resulting from three different hydrologic 

scenarios: the minimum probable, most probable, and maximum probable reservoir inflow 

conditions. Projected reservoir operations are modified during the water year (WY) as runoff 

forecasts are adjusted to reflect existing snowpack, basin storage, flow conditions, and as 

changes occur in projected water deliveries. 

Summary of Projected 2023 Operations

Upper Basin. Taking into account (1) the existing water storage conditions in the basin, (2) 

the August 2022 24-Month Study21 projection of the most probable near-term water supply 

conditions in the basin, (3) the concept of operational neutrality as outlined in the Lake Powell 

annual operating decision in water year 2022 (May 3rd Letter),

22 (4) the concept of preserving 

the benefits to Glen Canyon Dam facilities and operations in 2023 of the operating decisions 

made in water year 2022,23 and (5) Section 6.D.1 of the 2007 Interim Guidelines, the Lower 

Elevation Balancing Tier will govern the operation of Lake Powell for water year 2023. 

Subject to decisions regarding preservation of the benefits to Glen Canyon Dam facilities and 

operations, the August 2022 24-Month Study of the most probable inflow scenario projects the 

water year 2023 release from Glen Canyon Dam to be 7.00 million acre-feet (maf) (8,630 

million cubic meters [mcm]). Given the hydrologic variability of the Colorado River System 

and consistent with Section 6.D.1 of the 2007 Interim Guidelines, the projected water year 

release from Lake Powell in 2023 will range from 7.00 maf (8,630 mcm) to 9.50 maf (11,720 

mcm). Because the 2022 operations were intended to protect critical elevations at Lake Powell, 

Reclamation will implement operations to protect these critical elevations and preserve the 

benefits of the 2022 operations in water year 2023. Specifically, Reclamation modeled Lower 

Elevation Balancing Tier operations in WY 2023 as follows in the August 24-Month Study: 

• The Glen Canyon Dam annual release has initially been set to 7.00 maf (8,630 mcm) 

and in April 2023 Reclamation will evaluate hydrologic conditions to determine if 

balancing releases may be appropriate pursuant to the 2007 Interim Guidelines 

• Balancing releases will be limited (with a minimum of 7.00 maf (8,630 mcm) to protect 

Lake Powell from declining below elevation 3,525 feet (1,074.42 meters) at the end of 

December 2023 

• Balancing releases will account for operational neutrality of the 0.480 maf (592 mcm) 

that was retained in Lake Powell under the May 2022 action. Any Lake Powell 

balancing release volume will be calculated as if the 0.480 maf (592 mcm) had been 

delivered to Lake Mead in WY 2022 

21 The 24-Month Study refers to the operational study conducted by Reclamation to project future reservoir 

operations. The most recent 24-Month Study report is available on Reclamation’s Water Operations websites and 

is updated each month. Available online at: https://www.usbr.gov/uc/water/crsp/studies/index.html and

https://www.usbr.gov/lc/region/g4000/24mo/index.html. 22 More information about Lake Powell’s operating decision for water year 2022 is available online: 

https://www.usbr.gov/uc/DocLibrary/Plans/20220503-2022DROA-GlenCanyonDamOperationsDecisionLetter508-DOI.pdf. 23 Information related to water year 2023 information can be found here: https://www.usbr.gov/newsroom/newsrelease/4294

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5 2023 AOP – November 22, 2022

• The modeling approach for WY 2023 will apply to 2024 for the purposes of the August 

24-Month Study 

Consistent with the provisions of the 2007 Interim Guidelines, and Reclamation’s commitment 

per the May 3rd letter to preserve the benefits to Glen Canyon Dam facilities from 2022 

Operations into 2023 and 2024, Reclamation will consult with the Basin States on monthly and 

annual operations. Reclamation will also consult with Basin Tribes, the Republic of Mexico, 

other federal agencies, water users and non-governmental organizations with respect to 

implementation of these monthly and annual operations. 

Reclamation will continue to monitor hydrologic and operational conditions and assess the 

need for additional responsive actions and changes to operations. Reclamation will continue to 

consult with the Basin States, Basin Tribes, the Republic of Mexico, and other partners on 

Colorado River operations to consider and determine whether additional measures should be 

taken to further enhance the preservation of these benefits, as well as recovery protocols,

including those of future protective measures for both Lake Powell and Lake Mead. 

For further information about the variability of projected inflow into Lake Powell, see the 2023 

Water Supply Assumptions section and the Lake Powell section within the Summary of 

Reservoir Operations in 2022 and Projected 2023 Reservoir Operations, and Tables 3 and 4. 

Lower Basin. Taking into account (1) the existing water storage conditions in the basin, 

(2) the most probable near-term water supply conditions in the basin, (3) the concept of 

operational neutrality as outlined in the Lake Powell annual operating decision in water year 

2022, 22 and (4) Section 2.D.1 of the 2007 Interim Guidelines, a Shortage Condition, consistent 

with Section 2.D.1.b, will govern the operation of Lake Mead for calendar year 2023 in 

accordance with Article III(3)(c) of the Operating Criteria and Article II(B)(3) of the 

Consolidated Decree. In addition, the Lower Basin Drought Contingency Plan Agreement (LB 

DCP Agreement) will also govern the operation of Lake Mead for calendar year 2023. 

Consistent with Sections III.B.1.a and III.B.2.a of Exhibit 1 to the LB DCP Agreement, DCP 

contributions will be required by Arizona and Nevada, respectively, in calendar year 2023. 

Creation and/or delivery of Intentionally Created Surplus (ICS) may be made consistent with

Section 3 of the 2007 Interim Guidelines and Sections III and IV of Exhibit 1 to the LB DCP 

Agreement, as applicable.

No unused apportionment for calendar year 2023 is anticipated. If any unused apportionment 

becomes available after adoption of this AOP, Reclamation, on behalf of the Secretary, may 

allocate any such available unused apportionment for calendar year 2023. Any such allocation 

shall be made in accordance with Article II(B)(6) of the Consolidated Decree, the Lower 

Colorado Region Policy for Apportioned but Unused Water24 (Unused Water Policy), and 

giving further consideration to the water conservation objectives of the July 30, 2014 

agreement for a pilot system conservation program (PSCP),25 the December 15, 2021 

24 Lower Colorado Region Policy for Apportioned but Unused Water, February 11, 2010. Available online at: 

https://www.usbr.gov/lc/region/g4000/UnusedWaterPolicy.pdf. 25 Available online at: 

https://www.usbr.gov/lc/region/programs/PilotSysConsProg/PilotSCPFundingAgreement7-30-2014.pdf. 

DRAFT
6 2023 AOP – November 22, 2022

Memorandum of Understanding (MOU) to maintain the elevation in Lake Mead (the “500 Plus 

Plan”),26 and as specified in Section 4.b of the LB DCP Agreement. 

In calendar year 2023, Colorado River water may be stored off-stream pursuant to individual 

Storage and Interstate Release Agreements (SIRAs) and 43 CFR Part 414 within the Lower 

Division States. The Secretary shall make Intentionally Created Unused Apportionment 

(ICUA) available to contractors in Arizona, California, or Nevada pursuant to individual SIRAs 

and 43 CFR Part 414. 

The Inadvertent Overrun and Payback Policy (IOPP),27 which became effective January 1, 

2004, will not be in effect during calendar year 2023 because overruns are not permitted in a 

Shortage Condition. In accordance with Section 2.6.e of the IOPP, further accumulation of 

inadvertent overruns in calendar year 2023 will be suspended.

Conserved Colorado River water, created through the PSCP,28 the LB DCP Agreement, the 500 

Plus Plan, and other voluntary agreements, is anticipated to be added to Lower Basin reservoirs 

pursuant to system conservation agreements in the Lower Basin in calendar year 2023. 

The 2007 Interim Guidelines adopted the ICS mechanism, which was expanded upon in the LB 

DCP Agreement, that among other things encourages the efficient use and management of 

Colorado River water in the Lower Basin. ICS may be created and delivered in calendar year 

2023 pursuant to the 2007 Interim Guidelines, applicable forbearance and delivery agreements, 

and the LB DCP Agreement. 

Consistent with Section 4 of the 2007 Interim Guidelines, Developed Shortage Supply (DSS) 

may be created and delivered in calendar year 2023. 

1944 United States-Mexico Water Treaty. A volume of 1.430 maf (1,760 mcm) of water will 

be available to be scheduled for delivery to Mexico during calendar year 2023 in accordance 

with Article 15 of the 1944 United States-Mexico Water Treaty, IBWC Minutes No. 242 and 

327, and Section III.A of IBWC Minute No. 323. The volume delivered may also be adjusted 

for water savings contributions as required under Section IV of IBWC Minute No. 323. In 

accordance with IBWC Minute No. 323, Mexico may create water for or take delivery of water 

from Mexico’s Water Reserve pursuant to Section III.C and Section V of IBWC Minute No. 

323.

26 Available online at: https://www.usbr.gov/lc/region/g4000/2021_MOU.pdf. 27 ROD for Implementation Agreement, Inadvertent Overrun and Payback Policy, and Related Federal Actions, 

Final Environmental Impact Statement, October 10, 2003 (69 Federal Register 12202, March 15, 2004). 

Available online at: https://www.usbr.gov/lc/region/g4000/crwda/crwda_rod.pdf. 28 More information about the PSCP in the Lower Basin can be found at: 

https://www.usbr.gov/lc/region/programs/PilotSysConsProg/pilotsystem.html. 

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7 2023 AOP – November 22, 2022

BASINWIDE DROUGHT RESPONSE OPERATIONS

The Colorado River Basin is experiencing a prolonged period of drought and record-low runoff 

conditions resulting in historically low reservoir levels at Lake Powell and Lake Mead. The 

period from 2000 through 2022 is the lowest 23-year inflow in the historic record and one of 

the lowest in the past 1,200 years.29 As a result of the exceptionally low runoff conditions over 

the past three years (2020, 2021, and 2022), drought response operations have been triggered at 

Lake Powell and Lake Mead consistent with the 2007 Interim Guidelines, Minute No. 323, and 

the 2019 Colorado River DCP agreements.

Upper Basin Drought Response Operations Agreement (DROA)

Reclamation staff have been working with the DROA30 Parties to develop and implement the 

2022 Plan since hydrologic projections in early 2021 indicated that Lake Powell could decline 

to below DROA’s Target Elevation of 3,525 feet (1,074.42 meters). Development of the 2022 

Plan involved drafting two components: a Framework document that contains provisions the 

DROA Parties will use to develop annual Plans and will remain relatively unchanged from year 

to year, and 2022 attachments to this Framework document to identify the specific operations 

during the May 2022 through April 2023 period. 

In July of 2021, Reclamation initiated an emergency release in accordance with the DROA 

after advance consultation and coordination with the Upper Division States, through the UCRC, 

and following consultation with and supporting communication from the Governors’ 

Representatives of the Colorado River Basin States. Additional consultation occurred with 

WAPA, 31 the National Park Service, and the U.S. Fish and Wildlife Service (USFWS). Under 

the Emergency Action provision, Reclamation planned to release an additional total of 0.181 

maf (223 mcm) in Calendar Year 2021, from Flaming Gorge, Blue Mesa and Navajo 

reservoirs. Reclamation later modified that plan to release 0.161 maf (199 mcm), based on 

increased risk of not fully meeting contract deliveries from Navajo Reservoir in water year 

2022. 

In January of 2022, Reclamation initiated a second DROA action after advanced consultation 

and coordination with the Upper Division States, through the UCRC, and following 

consultation with the Governors’ Representatives of the Colorado River Basin States. Pursuant 

to DROA, the first drought response that is considered is the modification of monthly release 

volumes from Lake Powell while maintaining the annual release volume pursuant to the 2007 

Interim Guidelines. Reclamation modified Lake Powell release volumes by reducing the 

monthly releases from January through April 2022, by a total volume of 0.350 maf (432 mcm). 

This volume was scheduled to be added back into releases scheduled for June through 

29 Study on the tree-ring reconstruction record for the Upper Colorado River Basin is available online at: 

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2007GL029988

30 Available online at: https://www.usbr.gov/dcp/docs/final/Attachment-A1-Drought-Response%20OperationsAgreement-Final.pdf. 31 Per Interagency Agreement No. 19-WC-40-746, section 2.5, “Reclamation will ensure WAPA is given a 

meaningful opportunity to participate,” including the opportunity to participate in the potential development of a 

drought response operations plan.

DRAFT
8 2023 AOP – November 22, 2022

September 2022; however, in May 2022, the Department of the Interior modified the annual 

release volume from Lake Powell from 7.48 maf (9,230 mcm) to 7.00 maf (8,630 mcm), in 

accordance with Sections 6 and 7.D of the 2007 Interim Guidelines. 

In April of 2022, the DROA parties finalized the 2022 Plan for the duration of May 2022 

through April 2023.32 The Secretary of the Interior through her designee approved the 2022 

Plan on April 29, 2022,33 as summarized and including the following key operational elements: 

1. Drought Response Operations releases of approximately 0.500 maf (617 mcm) from 

Flaming Gorge Dam 

2. Possible Drought Response Operations releases from Blue Mesa Reservoir in Fall 2022 

and Winter 2023, contingent upon available release volumes 

3. Possible Drought Response Operations releases from Navajo Reservoir in Fall 2022 or 

Winter 2023, contingent upon available release volume 

4. Possible operational adjustments at Glen Canyon Dam in Winter 2023 

5. No anticipated recovery of DROA release volumes through the term of the 2022 Plan 

On July 18, 2022, the UCRC sent a letter to the Department of the Interior through Reclamation 

Commissioner Touton to inform Reclamation of its 5-Point Plan in response to Commissioner 

Touton’s challenge to find 2 to 4 million acre-feet of water in the next two years. In that letter, 

the UCRC indicated that the Upper Division States intend to commence development of a 2023 

Drought Response Operations Plan (2023 Plan) in August 2022, with finalization in April 2023 

consistent with the Drought Response Operations Plan Framework (Framework). A 2023 Plan 

must meet all the requirements of the Drought Response Operations Agreement and the 

Framework.

34 

2022 Powell Release Reduction; Operational Neutrality and Protection of the 

Glen Canyon Dam Facilities and Operations

In light of the prolonged drought, low runoff conditions, and depleted storage at Lake Powell, 

the Department of the Interior, in consultation with the Basin States and others, implemented an 

action under Sections 6 and 7.D of the 2007 Interim Guidelines specifically reducing the Glen 

Canyon Dam annual release from 7.48 maf (9,230 mcm) to 7.00 maf (8,630 mcm) in water year 

2022. This action, based on the May 3rd Letter, was undertaken in conjunction with 2022 

DROA actions resulting in adding approximately one million additional acre-feet (1,230 mcm) 

of storage, or 16.00 feet (4.88 meters) of pool elevation, by April 2023. 

32 Drought Response Operations Framework and Plan: https://www.usbr.gov/uc/DocLibrary/Plans/20220420-

2022DroughtResponseOperationsPlan-Signed-508-UCRO.pdf. 33 Department of Interior Approval Memo: https://www.usbr.gov/uc/DocLibrary/Plans/20220429-

2022DroughtResponseOperationsPlan-ApprovalMemo-508-DOI.pdf. 34 The UCRC letter can be found here: http://www.ucrcommission.com/wp-content/uploads/2022/07/2022-July18-Letter-to-Reclamation.pdf 

DRAFT
9 2023 AOP – November 22, 2022

The reduction of releases from Lake Powell from 7.48 maf (9,230 mcm) to 7.00 maf (8,630 

mcm)in water year 2022 will result in a reduced release volume of 0.480 maf (592 mcm) that, 

consistent with operations under the 2007 Interim Guidelines, normally would have been 

released from Glen Canyon Dam to Lake Mead as part of the 7.48 maf (9,230 mcm) annual 

release volume. The reduction of releases from Glen Canyon Dam in water year 2022 

(resulting in increased storage in Lake Powell) will not affect future operating determinations 

and will be accounted for “as if” this volume of water had been delivered to Lake Mead. The 

August 2022 24-Month Study modeled Lake Powell and Lake Mead as if the 0.480 maf (592 

mcm) had been delivered to Lake Mead for operating tier/condition purposes both for the U.S. 

Lower Basin and for Mexico. Actual delivery and final accounting of this volume of water will 

take place at a later date in consultation with the Basin States, Basin Tribes, and Mexico. 

Lower Basin MOU – 500 Plus Plan

The August 2021 24-Month Study Minimum Probable inflow scenario projected that Lake 

Mead’s elevation will be below elevation 1,030 feet (313.9 meters) in July 2023. Consistent 

with Section V.B.2 of Exhibit 1 to the Lower Basin DCP, this projection triggered consultation 

among the Secretary and Lower Division States to determine what additional measures will be 

taken to avoid and protect against the potential for Lake Mead to decline below 1,020 feet 

(310.9 meters). Consistent with this provision, in December 2021, a Lower Basin MOU

established a cooperative effort commonly referred to as the “500 Plus Plan” to facilitate nearterm actions to maintain the water surface elevation of Lake Mead. The 500 Plus Plan aims to 

generate an additional 0.500 maf (617 mcm) of voluntary conservation each calendar year in 

2022 and 2023, relative to the June 2021 24-Month Study modeling assumptions, in addition to 

the required shortage reductions and DCP contributions under the 2007 Interim Guidelines and 

Lower Basin DCP Agreement, respectively. As of October 2022, approximately 0.417 maf

(514 mcm) is projected to be conserved through calendar year 2023 in accordance with the 500 

Plus Plan.

35 Reclamation will continue working with the Lower Basin to enter into agreements 

for system conservation water that can be applied towards the 500 Plus Plan. 

Supplemental Environmental Impact Statement (SEIS)

As directed by the Secretary, on November 17, 2022, Reclamation published a Federal Register

Notice indicating its intent to prepare a SEIS.

36 The purpose of the SEIS is to supplement the 

Environmental Impact Statement completed in 2007 for the 2007 Interim Guidelines in order to 

modify operating guidelines for the operation of Glen Canyon and Hoover Dam to address the 

historic drought and low runoff conditions in the Colorado River Basin. The need for the 

revised operating guidelines is based on the potential that continued low runoff conditions in 

the Colorado River Basin could lead to critically low reservoir conditions at Lake Powell and 

Lake Mead that impact both water delivery and hydropower operations in 2023 and 2024. 

While it is premature at this time to identify any potential changes to Glen Canyon Dam or 

35 The yearly accounting for the 500 Plus Plan volumes will be reflected in Reclamation’s water accounting report. 

The water accounting reports are available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 36 Federal Register Notice available online at: https://www.federalregister.gov/documents/2022/11/17/2022-

25004/notice-of-intent-to-prepare-a-supplemental-environmental-impact-statement-for-december-2007-record. 

DRAFT
10 2023 AOP – November 22, 2022

Hoover Dam operations, potential changes to such operations may be adopted and implemented 

in 2023 or subsequent years. 

2022 HYDROLOGY SUMMARY AND RESERVOIR STATUS

Much below average streamflows37 were observed throughout much of the Colorado River 

Basin during water year 2022. Unregulated38 inflow to Lake Powell in water year 2022 was 

6.08 maf (7,500 mcm), or 63 percent of the 30-year average39 which is 9.60 maf (11,840 mcm). 

Unregulated inflow to Flaming Gorge, Blue Mesa, and Navajo Reservoirs was 64, 71, and 63 

percent of average, respectively.

Precipitation in the Upper Colorado River Basin was median40 during water year 2022. On 

September 30, 2022, the cumulative precipitation received within the Upper Colorado River 

Basin for water year 2022 was 100 percent of median. 

Snowpack conditions trended below average across most of the Colorado River Basin 

throughout the snow accumulation season. The basinwide snow water equivalent measured 

96 percent of the median peak on March 24, 2022, which is around two weeks earlier than the 

peak seasonal accumulation day of April 6. On April 1, 2022, the snow water equivalents for 

the Green River, Upper Colorado River Headwaters, and San Juan River Basins were 75, 89, 

and 103 percent of median, respectively.

During the 2022 spring runoff period, inflows to Lake Powell peaked on June 3, 2022 at 

approximately 28,300 cubic feet per second (cfs) (800 cubic meters per second [cms]). The 

April through July unregulated inflow volume for Lake Powell was 3.75 maf (4,630 mcm) 

which was 59 percent of average.

Lower Basin tributary inflows above Lake Mead were near average/median for water year 

2022. Tributary inflow measured at the Little Colorado River near Cameron gage for water 

year 2022 totaled 0.164 maf (202 mcm), or 139 percent of average. Tributary inflow measured 

37 Streamflow statistics throughout this document are provided by the National Weather Service’s Colorado Basin 

River Forecast Center and are based on the average/median for the 30-year period 1991-2020, unless otherwise 

noted. Hydrologic conditions are described in the following manner: much above average/median (greater than 

130%), above average/median (111%-130%), near average/median (90%-110%), below average/median (70%-

89%), and much below average/median (less than 70%). Reservoir specific ROD descriptions are used in place of

this terminology where applicable. 

38 Unregulated inflow adjusts for the effects of operations at upstream reservoirs. It is computed by adding the 

change in storage and the evaporation losses from upstream reservoirs to the observed inflow. Unregulated inflow 

is used because it provides an inflow time series that is not biased by upstream reservoir operations.

39 Inflow statistics throughout this document will be compared to the mean of the 30-year period 1991-2020, 

unless otherwise noted. 40 Snowpack, snow water equivalent and precipitation statistics throughout this document are provided by the 

Natural Resources Conservation Service and are based on the median for the 30-year period 1991-2020, unless 

otherwise noted. Hydrologic conditions are described in the following manner: much above average/median 

(greater than 130%), above average/median (111%-130%), near average/median (90%-110%), below 

average/median (70%-89%), and much below average/median (less than 70%). Reservoir specific ROD 

descriptions are used in place of this terminology where applicable. 

DRAFT
11 2023 AOP – November 22, 2022

at the Virgin River at Littlefield gage for water year 2022 totaled 0.115 maf (142 mcm), or 67 

percent of average.

Below Hoover Dam, tributary inflow for water year 2022 measured at the Bill Williams River 

below Alamo Dam gage totaled 0.018 maf (22 mcm), and tributary inflow measured at the Gila 

River near Dome gage totaled 0.007 maf (9 mcm).41

The Colorado River total system storage experienced a net decrease of 3.38 maf (4,170 mcm) 

in water year 2022. Reservoir storage in Lake Powell decreased during water year 2022 by 

1.46 maf (1,800 mcm). Reservoir storage in Lake Mead decreased during water year 2022 by 

1.69 maf (2,080 mcm). At the beginning of water year 2022 (October 1, 2021), Colorado River 

total system storage was 38 percent of capacity. As of September 30, 2022, total system 

storage was 33 percent of capacity.

Tables 1 and 2 list the October 1, 2022, reservoir vacant space, live storage, water elevation, 

percent of capacity, change in storage, and change in water elevation during water year 2022. 

41 Tributary inflows from the Bill Williams River and Gila River to the mainstream are very sporadic. These flows 

occur very seldom and when they do, they are typically of high magnitude. 

DRAFT
12 2023 AOP – November 22, 2022

Table 1. Reservoir Conditions on October 1, 2022 (English Units)

Reservoir Vacant 

Space

Live 

Storage

Water

Elevation

Percent of 

Capacity

Change in 

Storage

Change in 

Elevation

(maf) (maf) (ft) (%) (maf) (ft) 

Fontenelle 0.065 0.274 6,498.08 82 0.044 6.3

Flaming Gorge 0.991 2.68 6,013.01 73 -0.270 -6.1

Blue Mesa 0.533 0.292 7,446.72 35 0.051 10.1

Navajo 0.776 0.872 6,020.65 53 -0.031 -3.4 

Lake Powell 17.52 5.80 3,529.33 25 -1.46 -16.0

Lake Mead 18.79 7.33 1,045.03 28 -1.69 -22.7

Lake Mohave 0.215 1.60 639.17 88 0.030 1.1

Lake Havasu 0.040 0.579 447.96 94 -0.010 -0.5

Totals 38.93 19.42 33 -3.38

Table 2. Reservoir Conditions on October 1, 2022 (Metric Units)

Reservoir Vacant 

Space

Live 

Storage

Water

Elevation

Percent of 

Capacity

Change in 

Storage

Change in 

Elevation

(mcm) (mcm) (m) (%) (mcm) (m)

Fontenelle 81 338 1,980.61 82 54 1.9

Flaming Gorge 1,223 3,310 1,832.77 73 -333 -1.9

Blue Mesa 658 360 2,269.76 35 63 3.1

Navajo 958 1,080 1,835.09 53 -39 -1.0 

Lake Powell 21,610 7,150 1,075.74 25 -1,800 -4.9

Lake Mead 23,180 9,040 318.53 28 -2,082 -6.9

Lake Mohave 265 1,970 194.82 88 37 0.3

Lake Havasu 49 714 136.54 94 -12 -0.2

Totals

DRAFT

48,020 23,950 33 -4,170
13 2023 AOP – November 22, 2022

2023 WATER SUPPLY ASSUMPTIONS

For 2023 operations, three reservoir unregulated inflow scenarios were developed and 

analyzed: minimum probable, most probable, and maximum probable.

There is considerable uncertainty associated with streamflow forecasts and projections of 

reservoir operations made a year in advance. The National Weather Service’s Colorado Basin 

River Forecast Center (CBRFC) forecasts the inflow for the minimum probable (90 percent 

exceedance), most probable (50 percent exceedance), and maximum probable (10 percent 

exceedance) inflow scenarios using an Ensemble Streamflow Prediction model. Based upon 

the August CBRFC forecast, the range of unregulated inflows is projected to be as follows:

• The forecasted minimum probable unregulated inflow to Lake Powell in water year 

2023 is 4.70 maf (5,800 mcm), or 49 percent of average.

• The forecasted most probable unregulated inflow to Lake Powell in water year 2023 is 

8.30 maf (10,240 mcm), or 86 percent of average.

• The forecasted maximum probable unregulated inflow to Lake Powell in water year 

2023 is 15.70 maf (19,370 mcm), or 163 percent of average.

Projected unregulated inflow volumes42 into Lake Powell for specific time periods for these 

three forecasted inflow scenarios are shown in Tables 3 and 4. 

Inflows to the mainstream from Lake Powell to Lake Mead, Lake Mead to Lake Mohave, Lake 

Mohave to Lake Havasu, and below Lake Havasu are projected using historic data over the 

five-year period of January 2017 through December 2021, inclusive. These five years of 

historic data are representative of the most recent hydrologic conditions in the Lower Basin. 

The most probable side inflows into each reach are estimated as the arithmetic mean of the 

five-year record. The maximum probable and minimum probable projections for each reach 

are the 10 percent and 90 percent exceedance values, respectively, of the five-year record. For 

the reach from Lake Powell to Lake Mead, the minimum probable inflow during water year 

2023 is 0.633 maf (781 mcm), the most probable inflow is 0.810 maf (999 mcm), and the 

maximum probable inflow is 1.02 maf (1,260 mcm). 

The projected monthly volumes of inflow were input into the 24-Month Study and used to 

project potential reservoir operations for 2023. Starting with the August 2022 24-Month Study 

projection of the October 1, 2023 reservoir storage conditions, the projected monthly releases 

for each reservoir were adjusted until release and storage levels best accomplished project 

purposes and applicable operational objectives.

For the latest monthly projections for the major reservoirs in the Colorado River system, please 

see the most recent 24-Month Study report available on these Reclamation websites: 

42 24-Month Study projections using the CBRFC unregulated inflow forecast do not represent the full range of 

future possibilities that could occur with different scenarios. For more information, please see the Colorado River 

Modeling website online at: https://www.usbr.gov/lc/region/g4000/riverops/coriver-projections.html.

DRAFT
14 2023 AOP – November 22, 2022

https://www.usbr.gov/uc/water/crsp/studies/index.html, or

https://www.usbr.gov/lc/region/g4000/24mo/index.html. 

Table 3. Projected Unregulated Inflow into Lake Powell for Water Year 2023 (English Units)43

Time

Period

Minimum 

Probable 

(maf)

Most

Probable 

(maf)

Maximum 

Probable 

(maf)

10/2022 – 12/2022 0.72 1.03 1.65

1/2023 – 3/2023 0.55 1.01 1.94

4/2023 – 7/2023 3.08 5.63 10.86

8/2023 – 9/2023 0.35 0.65 1.25

10/2023 – 12/2023 1.01 1.23 1.55

Water Year 2023 4.70 8.32 15.70

Calendar Year 2023 4.99 8.52 15.60

Table 4. Projected Unregulated Inflow into Lake Powell for Water Year 2023 (Metric Units)

Time

Period

Minimum 

Probable 

(mcm)

Most

Probable 

(mcm)

Maximum 

Probable 

(mcm)

10/2022 – 12/2022 890 1,270 2,040

1/2023 – 3/2023 680 1,250 2,390

4/2023 – 7/2023 3,800 6,940 13,400

8/2023 – 9/2023 430 800 1,540

10/2023 – 12/2023 1,250 1,520 1,910

Water Year 2023 5,800 10,260 19,370

Calendar Year 2023 6,160 10,510 19,240

43 All values in Tables 3 and 4 are projected inflows based upon the August 2022 CBRFC forecast. The CBRFC 

Most Probable forecast is issued as monthly values. The CBRFC Minimum and Maximum Probable forecasts are 

issued as water year totals, which Reclamation disaggregates to monthly values using monthly proportions of the 

10th and 90th percentiles, respectively, of the 1991-2020 unregulated inflow.

DRAFT
15 2023 AOP – November 22, 2022

SUMMARY OF RESERVOIR OPERATIONS IN 2022 AND 

PROJECTED 2023 RESERVOIR OPERATIONS

The operation of the Colorado River reservoirs has affected some aquatic and riparian 

resources. Controlled releases from dams have modified temperature, sediment load, and flow 

patterns, resulting in increased productivity of some riparian and non-native aquatic resources 

and the development of economically significant sport fisheries. However, these same releases 

can have detrimental effects on endangered and other native species. Operating strategies 

designed to protect and enhance aquatic and riparian resources have been established after 

appropriate National Environmental Policy Act compliance at several locations in the Colorado 

River Basin.

In the Upper Basin, public stakeholder work groups have been established at Fontenelle Dam, 

Flaming Gorge Dam, the Aspinall Unit, and Navajo Dam. These work groups provide a public 

forum for dissemination of information regarding ongoing and projected reservoir operations 

throughout the year and allow stakeholders the opportunity to provide information and 

feedback with respect to ongoing reservoir operations. Additionally, the Glen Canyon Dam 

Adaptive Management Work Group (AMWG)44 was established in 1997 as a chartered 

committee under the Federal Advisory Committee Act of 1972 (Public Law 92-463). 

Modifications to projected operations are routinely made based on changes in forecasted 

conditions or other relevant factors. Within the parameters set forth in the Law of the River 

and considering the Upper Colorado River Endangered Fish Recovery Program (UCRIP),45 the 

San Juan River Basin Recovery Implementation Program (SJRIP),46 Section 7 consultations 

under the Endangered Species Act, and other downstream concerns, modifications to projected 

monthly operations may be based on other factors in addition to changes in streamflow 

forecasts. Decisions on spring peak releases and downstream habitat target flows may be made 

midway through the runoff season. Reclamation will conduct meetings with Recovery 

Program participants, the USFWS, other Federal agencies, representatives of the Basin States, 

and with public stakeholder work groups to facilitate the discussions necessary to finalize sitespecific projected operations.

The following paragraphs discuss reservoir operations in 2022 and the range of probable 

projected 2023 operations of each of the reservoirs with respect to applicable provisions of 

compacts, the Consolidated Decree, statutes, regulations, contracts, agreements, and instream 

flow needs for maintaining or improving aquatic and riparian resources where appropriate.

44 Information on the AMWG can be found at: https://www.usbr.gov/uc/progact/amp/amwg.html. 45 Information on the UCRIP can be found at: http://coloradoriverrecovery.org. 46 Information on the SJRIP can be found at: https://www.fws.gov/southwest/sjrip. 

DRAFT
16 2023 AOP – November 22, 2022

Fontenelle Reservoir

Reservoir storage in Fontenelle increased during water year 2022. At the beginning of water 

year 2022, Fontenelle storage was 69 percent of live capacity at elevation 6,491.82 feet 

(1,978.71 meters), with 0.230 maf (284 mcm) in storage. The unregulated inflow to Fontenelle 

during water year 2022 was 0.744 maf (917 mcm) which is 69 percent of average. At the end 

of the water year, September 30, 2022, Fontenelle storage was at 82 percent of live capacity at 

elevation 6,498.08 feet (1,980.61 meters), with a storage of 0.274 maf (338 mcm) resulting in a 

net increase during water year 2022 of 0.044 maf (54 mcm). 

Hydrologic conditions in the Upper Green River Basin above Fontenelle were below average in 

water year 2022. Snowpack development tracked below median with below average fall 

conditions resulting in a below average runoff forecast. Peak snow water equivalent reached 

82 percent of seasonal median on April 18, 2022. The observed inflow during the April to July 

season was 0.449 maf (553 mcm), or 61 percent of average. 

Fontenelle Reservoir storage peaked at 98 percent of full capacity in water year 2022. The 

reservoir elevation peaked at 6,504.95 feet (1,982.71 meters) on July 22, 2022, which was 1.06 

feet (0.32 meters) below the spillway crest. Daily inflow peaked at 8,090 cfs (229 cms) on 

June 15, 2022. Reservoir releases were made to balance downstream water resources needs 

and power production, while also allowing for filling the reservoir to maintain sufficient water 

in storage for use through the fall and winter months. Due to the below average hydrologic 

conditions, there was a small spring peak release at Fontenelle Reservoir. 

Based on the August 2022 24-Month Study, the most probable April through July inflow for 

Fontenelle Reservoir during water year 2023 is 0.635 maf (783 mcm) or 86 percent of average. 

This volume exceeds the 0.334 maf (412 mcm) live storage capacity of Fontenelle Reservoir. 

For this reason, the most probable and maximum probable inflow scenarios would require 

releases during the spring that exceed the capacity of the powerplant to avoid uncontrolled 

spills from the reservoir. It is likely that Fontenelle Reservoir will fill during water year 2023. 

In order to minimize high spring releases and to maximize downstream water resources and 

power production, the reservoir will most likely be drawn down to about elevation 6,468.88 

feet (1,971.71 meters) by late March, which is 5.88 feet (1.79 meters) above the minimum 

operating level, and corresponds to a volume of 0.114 maf (140 mcm) of live storage. 

Beginning October 1, 2020, the area-capacity table for Fontenelle Reservoir was updated based 

on a 2010 and 2019 Reclamation Survey. The live capacity decreased from 0.345 maf (426 

mcm) to 0.334 maf (412 mcm). The active capacity decreased from 0.264 maf (326 mcm) to 

0.257 maf (317 mcm). 

Flaming Gorge Reservoir

Reservoir storage in Flaming Gorge decreased during water year 2022. At the beginning of 

water year 2022, Flaming Gorge storage was 82 percent of live capacity at elevation 6,019.15 

feet (1,834.64 meters), with 2.95 maf (3,640 mcm) in storage. The unregulated inflow to 

Flaming Gorge during water year 2022 was 0.900 maf (1,110 mcm) which is 64 percent of 

average. At the end of the water year, Flaming Gorge storage was at 74 percent of live capacity 

DRAFT
17 2023 AOP – November 22, 2022

at elevation 6,013.01 feet (1,832.77 meters), with 2.68 maf (3,310 mcm) resulting in a net 

decrease during water year 2022 of 0.270 maf (333 mcm). 

Spring period hydrologic classification in the Upper Green River Basin above Flaming Gorge 

was moderately dry in water year 2022 where the snowpack tracked below median with below 

average fall conditions resulting in below average runoff forecasts. Peak snow water 

equivalent reached 83 percent of seasonal median on April 18, 2022. The May forecast for the 

April through July inflow into Flaming Gorge Reservoir was 0.550 maf (678 mcm), or 57 

percent of average. The observed inflow during the spring runoff season was 0.539 maf (665 

mcm), or 56 percent of average. Observed flow volumes from the Yampa River Basin fell into 

the moderately dry hydrologic condition. 

A 2022 Plan47 was approved by the Upper Division States, the Upper Colorado River 

Commission, and the Department of the Interior. Per the 2022 Plan an additional 0.500 maf 

(617 mcm) is scheduled to be delivered from Flaming Gorge Reservoir from May 2022 through 

April 2023 to Lake Powell. 

The Flaming Gorge Operation Plan for May 2022 through April 2023 (FG-Ops) has been 

developed and approved by Reclamation and includes the 2022 Plan. The FG-Ops outlines two 

of the three UCRIP flow requests.

48 The moderately dry scenario includes the Larval Trigger 

Study Plan (LTSP) spring release (spring release based on a biological trigger)49 and the 

smallmouth bass (SMB) flow spike (to disrupt the spawning success of non-native smallmouth 

bass).

50

Spring releases were timed with a biological trigger. After public notification, releases from 

Flaming Gorge Dam were increased to full powerplant capacity 4,600 cfs (130 cms) and full 

bypass capacity 4,000 cfs (113 cms) on May 25, 2022 for eleven days then ramped down by 

2,000 cfs/day (56.6 cms/day) to 850 cfs (24.1 cms). Yampa River flows at the Deerlodge gage 

during the spring peak releases peaked at 11,300 cfs (320 cms) on May 20, 2022. The peak 

release from Flaming Gorge Dam occurred after the Yampa River peak. Flows measured on 

the Green River at the Jensen, Utah gage reached levels at or above 8,300 cfs (235 cms) for 33 

days on May 10, 2022, with a peak of 16,600 cfs (470 cms) on May 31, 2022. The spring peak 

release in Reach 2 for this hydrologic classification is greater than or equal to 8,300 cfs (235 

cms) for 7 or more days.

47 Drought Response Operations Framework and Plan: https://www.usbr.gov/uc/DocLibrary/Plans/20220420-

2022DroughtResponseOperationsPlan-Signed-508-UCRO.pdf. 48 The adaptive management process will rely on ongoing or added Recovery Program activities for monitoring 

and studies to test the outcomes of modifying the flows and release temperatures from Flaming Gorge Dam. ROD 

Operation of Flaming Gorge Dam Final Environmental Impact Statement, February 2006. Available online at: 

https://www.usbr.gov/uc/envdocs/rod/fgFEIS/final-ROD-15feb06.pdf 49 The LTSP’s primary objective is to determine the effects of timing of Flaming Gorge spring release on 

razorback sucker larvae in the reach below the confluence of the Green and Yampa Rivers. The LTSP Report is 

available online at: https://www.usbr.gov/uc/water/crsp/wg/fg/twg/twgSummaries.html. 50 Smallmouth bass flow spike study plan titled: Evaluate effects of flow spikes to disrupt reproduction of

smallmouth bass in the Green River downstream of Flaming Gorge Dam. K.R. Bestgen, 2018. Available online 

at: https://www.coloradoriverrecovery.org/documents-publications/technicalreports/isf/Bestgen2018Smallmouth%20bass%20study%20planNovember2018.pdf. 

DRAFT
18 2023 AOP – November 22, 2022

The releases for the SMB flow spike began increasing to full powerplant capacity on June 21, 

2022. Full power plant releases, 4,600 cfs (130 cms), were sustained for 3 days (June 21-24, 72 

hours) followed by a 2-day ramp down at a maximum of 2,000 cfs/day (56.6 cms/day) that 

concluded the experiment early June 26. 

In water year 2022, Flaming Gorge Reservoir was operated in accordance with the 2006 

Flaming Gorge ROD. The April through July observed unregulated inflow resulted in a 

moderately dry hydrologic classification. Due to spring flows being greater than 14,000 cfs for 

more than 4 days in Reach 2, per the 2022 Plan, an average hydrologic operation was 

conducted for summer, autumn, and winter base flow. These releases are within the 2000 Flow 

and Temperature Recommendations range of 1,500 cfs (42.4 cms) to 2,400 cfs (67.9 cms) at 

Reach 2 including being within the +/-40 percent range flexibility. Summer base flow average 

daily releases ranged from 1,100 cfs (31.3 cms) to 1,940 cfs (54.9 cms). Winter base flow 

releases are projected to be 1,600 cfs (45.3 cms) to approximately 1,700 cfs (48.1 cms). Daily 

base flows will likely fluctuate during the winter in response to hydropower needs during 

December through February. 

A spring peak release is projected to occur in May or June 2023 and will be timed to coincide 

with either the peak flows of the Yampa River or emergence of razorback sucker larvae. 

Reclamation is considering long-term implementation strategies for the UCRIP LTSP. 

Based on the August 2022 24-Month Study, the most probable April through July unregulated 

inflow scenario for Flaming Gorge Reservoir during water year 2023 is 0.830 maf (1,020

mcm), or 86 percent of average. The peak elevation is expected to be approximately 6,012.35 

feet (1,832.56 meters) near mid-July 2023. By the end of water year 2023, Flaming Gorge 

Reservoir is projected to be at elevation 6,012.08 feet (1,832.48 meters), with a storage of 2.65 

maf (3,270 mcm), or 73 percent of live capacity. 

Under the minimum probable 2023 April through July inflow forecast of 0.467 maf (576 mcm), 

a 4,600 cfs (130 cms) 2023 spring peak release will be implemented. Under the maximum 

probable 2023 April through July inflow forecast of 1.61 maf (1,980 mcm), an 8,600 cfs (243 

cms) spring peak release will be implemented. 

The UCRIP, in coordination with Reclamation, USFWS, and WAPA, will continue conducting 

studies associated with floodplain inundation. Such studies may result in alternatives for 

meeting flow and temperature recommendations at lower peak flow levels where feasible.

Beginning May 1, 2022, the area-capacity table for Flaming Gorge Reservoir was updated 

based on a 2019 and 2020 Reclamation Survey. The live capacity decreased from 3.75 maf 

(4,620 mcm) to 3.67 maf (4,530 mcm). The active capacity decreased from 3.52 maf (4,340 

mcm) to 3.43 maf (4,240 mcm). Due to potential impacts from DROA releases, Reclamation 

conducted a survey in June 2022 of boat ramps, marinas and related infrastructure in Flaming 

Gorge Reservoir. 

DRAFT
19 2023 AOP – November 22, 2022

Blue Mesa, Morrow Point, and Crystal Reservoirs (Aspinall Unit)

Reservoir storage content in Blue Mesa increased during water year 2022. At the beginning of 

water year 2022, Blue Mesa storage content was 53 percent of live capacity at elevation 

7,436.58 feet (2,266.67 meters), with 0.241 maf (297 mcm) in storage. The unregulated inflow 

to Blue Mesa during water year 2022 was 0.639 maf (788 mcm), which was 71 percent of 

average. At the end of the water year, Blue Mesa storage content was 34 percent of live

capacity at elevation 7,443.57 feet (2,268.80 meters), with 0.275 maf (339 mcm) resulting in a 

net increase during water year 2022 of 0.034 maf (42 mcm). 

Near average snowpack conditions occurred during the winter months of water year 2022 in the 

Gunnison River Basin. Snow measurement sites in the basin reported above to near median

seasonal snow water equivalent levels throughout the winter and into the spring of 2022 

resulting in an April 1, 2022 snow water equivalent for the Gunnison River Basin that was 103 

percent of median, using the 1991-2020 hydrologic period of record. 

The fall through winter releases from Crystal Dam were consistently near 350 cfs (9.9 cms)

after the Gunnison Tunnel ended diversions for irrigation season on November 1, 2021. On

March 21, 2022, releases from Crystal Dam were increased for the 2022 irrigation season as 

operation of the Gunnison Tunnel began diverting 200 cfs (5.7 cms). Flows through the Black 

Canyon were maintained within the range of approximately 350 cfs (9.9 cms) to approximately 

475 cfs (13.4 cms) until May 14, 2022. 

The May 2022 final forecast51 for the unregulated inflow to Blue Mesa for the April through 

July runoff period was 0.490 maf (604 mcm), which was 77 percent of average. This forecast 

was used to establish the hydrologic category for water year 2022 as moderately dry with a 

peak flow target established for the Whitewater reach of the Gunnison River of 5,000 cfs

(141.5 cms) for 1 day. 

On May 14, 2022, releases from Crystal, Morrow Point and Blue Mesa were increased to target 

downstream flow levels and durations described in the Aspinall ROD and the Black Canyon 

Water Right Decree52. These releases targeted 24-hour peak flows of 5,000 cfs (141.5 cms) in 

the Whitewater reach and 2,410 cfs (68.2 cms) in the Black Canyon. During spring peak 

operations, flows measured in the Whitewater Reach of the Gunnison River achieved an 

average daily peak flow of 5,750 cfs (163 cms) on May 19, 2020. Releases from Crystal Dam 

on May 18 and 19, 2020 resulted in a 24-hour average peak flow through the Black Canyon and 

the Gunnison River Gorge of 2,745 cfs (77.7 cms) as measured at the streamgage located on the 

Gunnison River below the Gunnison Tunnel. Gunnison River flows in the Black Canyon met 

or exceeded the flows described in the Black Canyon Water Right Decree. 

51 The term “final forecast” or “official forecast” refers to the CBRFC runoff forecast for unregulated inflow into 

CRSP reservoirs that is received by Reclamation during the first few business days of each month.

52 Decree quantifying the Federal Reserved Water Right for Black Canyon of the Gunnison National Park (State of 

Colorado District Court, Water Division Four, Case Number 01CW05), signed on December 31, 2008.

DRAFT
20 2023 AOP – November 22, 2022

For water year 2023, the Aspinall Unit will be operated in compliance with the 2012 Aspinall 

ROD, including all required consultations and consistent with applicable law, while 

maintaining and continuing to meet its Congressionally authorized purposes. 

Based on the August 2022 24-Month Study, the projected most probable unregulated inflow for 

water year 2023 into Blue Mesa Reservoir is 0.820 maf (1,011 mcm), or 91 percent of average. 

The reservoir is expected to reach a seasonal low elevation of 7,433.21 feet (2,265.64 

meters) in October 2022. The peak elevation is expected to be approximately 7,488.55 feet 

(2,282.51 meters) near the end of July 2023. By the end of water year 2023, Blue Mesa 

Reservoir is projected to be at elevation 7,481.20 feet (2,280.27 meters), with a storage content 

of 0.511 maf (630 mcm), or 62 percent of capacity.

Under the minimum probable 2023 April through July inflow forecast of 0.347 maf (428 

mcm), there will be 1-day spring peak release during the spring of 2023. Under the maximum 

probable 2023 April through July inflow forecast of 0.911 maf ( 1,124 mcm), a 10-day spring 

peak release will be implemented as described in the 2012 Aspinall ROD for water year 2023. 

Beginning October 1, 2020, the area-capacity table for Blue Mesa Reservoir was updated based 

on a 2017 Reclamation Survey. The live capacity decreased from 0.832 maf (1,030 mcm) to 

0.830 maf (1,020 mcm). The active capacity remained unchanged in the new survey at 0.748 

maf (923 mcm). 

Navajo Reservoir

Storage in Navajo Reservoir decreased during water year 2022. At the beginning of water year 

2022, Navajo storage was 55 percent of live capacity at elevation 6,024.05 feet (1,836.13

meters), with 0.903 maf (1,110 mcm) in storage. The modified unregulated inflow53 to Navajo

during water year 2022 was 0.574 maf (708 mcm), or 63 percent of average. At the end of the 

water year, Navajo storage was at 53 percent of live capacity at elevation 6,020.65 feet 

(1,835.09 meters), with 0.872 maf (1,080 mcm) resulting in a net decrease during water year 

2022 of 0.031 maf (39 mcm).

Reservoir storage in Navajo decreased throughout water year 2022 peaking at an elevation of 

6,029.43 feet (1,837.77 meters) on May 24, 2022. This was 55.57 feet (16.94 meters) below 

full pool. The April through July modified unregulated inflow into Navajo Reservoir in water 

year 2022 was 0.382 maf (471 mcm), or 61 percent of average. 

The San Juan Flow Recommendations,54 completed by the SJRIP in May 1999, provide flow 

recommendations that promote the recovery of the endangered CPM and razorback sucker, 

maintain important habitat for these two species as well as the other native species, and provide 

information for the evaluation of continued water development in the basin. In water year 

2022, Navajo Reservoir operated under the SJRIP and Reclamation’s interim operations. 

53 Modified unregulated inflow into Navajo Reservoir is calculated as the observed inflow adjusted for the San 

Juan Chama diversions and change in storage at Vallecito Reservoir.

54 Flow Recommendations for the San Juan River, May 1999. Available online at: 

https://www.fws.gov/southwest/sjrip/pdf/DOC_Flow_recommendations_San_Juan_River.pdf. 

DRAFT
21 2023 AOP – November 22, 2022

Under the interim operations, releases for SJRIP recovery purposes are dependent on annual 

hydrology and available water may be released as a spring peak release, an augmentation of 

existing target base flows, or for some other SJRIP purposes. The interim operations specify 

that the reservoir releases will be calculated to target an End of Water Year Storage Target 

elevation of 6,063.00 feet (1,848.00 meters). The interim operations also specify a minimum 

elevation of 6,050.00 feet (1,844.04 meters) for the purposes of calculating water available to 

release as a spring peak release. All available water over this target, minus the water required 

for minimum releases and contracts, will be available to be released as a spring peak 

hydrograph if the SJRIP requests. The available water must equate to at least 21 days at 5,000 

cfs (142 cms) to be released.

Navajo Reservoir was operated in compliance with the 2006 Navajo Reservoir ROD in 2022, 

including targeting the SJRIP’s recommended base flows. The target base flow was calculated 

using the weekly average of gaged flows throughout the critical habitat area from Farmington 

to Lake Powell. Based on the SJRIP and Reclamation’s interim operations for water year 2022, 

there was no spring peak release at Navajo Reservoir. 

During water year 2023, Navajo Reservoir will be operated in accordance with the 2006 

Navajo Reservoir ROD. Navajo Reservoir storage levels are expected to be below average in 

2023 under the most probable inflow forecast. Base releases from the reservoir will likely 

range from 250 cfs (7.07 cms) to 600 cfs (17.0 cms) through the winter. Based on the August 

2022 most probable April through July modified unregulated inflow forecast of 0.583 maf (719 

mcm) in 2023, the August 2022 24-Month Study projects no spring peak release would be 

recommended by the SJRIP and Reclamation’s interim operations for water year 2023. The 

reservoir is projected to reach a peak elevation of 6,049.12 feet (1,843.77 meters) in June 2023. 

The reservoir is projected to reach a minimum elevation of 6,020.79 feet (1,835.14 meters) in 

October 2022.

Under the minimum probable 2023 April through July inflow forecast of 0.281 maf (346 mcm), 

there will be no spring peak release during the spring of 2023. Under the maximum probable 

2023 April through July inflow forecast of 1.01 maf (1,240 mcm), a 51-day spring peak release 

will be recommended as described by SJRIP and Reclamation’s interim operations for water 

year 2023. 

Beginning October 1, 2021, the area-capacity table for Navajo Reservoir was updated based on 

a 2019 Reclamation Survey. The live capacity decreased from 1.70 maf (2,100 mcm) to 1.65 

maf (2,035 mcm). The active capacity decreased from 1.04 maf (1,280 mcm) to 1.02 maf

(1,260 mcm). 

Lake Powell

Reservoir storage in Lake Powell decreased during water year 2022. At the beginning of water 

year 2022, Lake Powell storage was 34 percent of live capacity at elevation 3,545.36 feet 

(1,080.63 meters), with 7.26 maf (8,950 mcm) in storage. The unregulated inflow to Lake 

Powell during water year 2022 was 6.08 maf (7,500 mcm) which is 63 percent of average. At 

the end of the water year, Lake Powell storage was at 25 percent of live capacity at elevation 

DRAFT
22 2023 AOP – November 22, 2022

3,529.33 feet (1,075.74 meters), with 5.80 maf (7,150 mcm) resulting in a net decrease during 

water year 2022 of 1.46 maf (1,800 mcm). 

The August 2021 24-Month Study was run to project the January 1, 2022, elevations of Lake 

Powell and Lake Mead and determine the water year 2022 operating tier for Lake Powell. 

Using the most probable inflow scenario, and with an 8.23 maf (10,150 mcm) annual release 

pattern for Lake Powell, the January 1, 2022, reservoir elevations of Lake Powell and Lake 

Mead were projected to be 3,535.40 feet (1,077.59 meters) and 1,065.85 feet (324.87 meters), 

respectively. Given these projections, the annual release volume from Lake Powell during 

water year 2022 was consistent with the Mid-Elevation Release Tier (Section 6.C.1 of the 2007 

Interim Guidelines), calling for 7.48 maf (9,230 mcm). 

As discussed in the Basinwide Drought Response Operations section above, in light of the 

prolonged drought, low runoff conditions, and depleted storage at Lake Powell, the Department 

of the Interior, in consultation with the Basin States and others, implemented an action under 

Sections 6 and 7.D of the 2007 Interim Guidelines specifically reducing the Glen Canyon Dam 

annual releases to 7.00 maf (8,630 mcm) in water year 2022. 

The April through July unregulated inflow to Lake Powell in water year 2022 was 3.75 maf 

(4,630 mcm) which was 59 percent of average. During the 2022 April through July runoff 

period, Lake Powell’s water surface elevation peaked on July 3, 2022, at 3,539.84 feet 

(1,078.94 meters), which was 160.16 feet (48.82 meters) below full pool. This elevation 

corresponds to a live storage content of 6.44 maf (7,940 mcm).

In water year 2022, Glen Canyon Dam was operated in compliance with the LTEMP ROD. 

The fourth Macroinvertebrate Production Flow (bug flow) experiment under the LTEMP was

designed and conducted during May through August 2022. During these four experiments, 

releases were held steady during Saturday and Sunday for the purpose of increasing production 

of aquatic insects. The total annual release from Glen Canyon Dam in water year 2022 did not 

change as a result of the experimental releases. 

The ten-year total flow of the Colorado River at Lee Ferry55 for water years 2013 through 2022 

is 85.58 maf (105,560 mcm). This total is computed as the sum of the flow of the Colorado 

River at Lees Ferry, Arizona, and the Paria River at Lees Ferry, Arizona, surface water 

discharge stations which are operated and maintained by the United States Geological Survey. 

Beginning July 1, 2022, the area-capacity table for Lake Powell Reservoir was updated based 

on a 2017 and 2018 Reclamation Survey. The live capacity decreased from 24.32 maf (30,000 

mcm) to 23.31 maf (28,760 mcm). The total capacity decreased from 26.22 maf (32,340 mcm) 

to 25.03 maf (30,870 mcm). 

55 A point in the mainstream of the Colorado River one mile below the mouth of the Paria River.

DRAFT
23 2023 AOP – November 22, 2022

2023 Operating Tier and Projected Operations for Glen Canyon Dam.

The January 1, 2023 reservoir elevations of Lake Powell and Lake Mead, as adjusted to reflect 

operational neutrality as outlined in the Lake Powell annual operating decision in water year 

2022,56 are projected under the most probable inflow scenario, with an 8.23 maf (10,150 mcm) 

release pattern in water year 2023, to be 3,505.66 feet (1,068.53 meters) and 1,047.61 feet 

(319.31 meters), respectively, based on the August 2022 24-Month Study. Given these 

projections, the operating tier and annual release volume from Lake Powell during water year 

2023 will be consistent with the Lower Elevation Balancing Tier (Section 6.D.1 of the 2007 

Interim Guidelines) and, under Section 6.D.1, when the projected January 1 Lake Powell 

elevation is below 3,525 feet (1,074.42 meters), the Secretary shall balance the contents of 

Lake Mead and Lake Powell, but shall release not more than 9.5 maf (11,720 mcm) and not 

less than 7.0 maf (8,630 mcm) from Lake Powell in the water year. Subject to decisions 

regarding preservation of the benefits to Glen Canyon Dam facilities and operations, the 

August 2022 24-Month Study of the most probable inflow scenario projects the water year 

2023 release from Glen Canyon Dam to be 7.00 maf (8,630 mcm). Given the hydrologic 

variability of the Colorado River System and consistent with Section 6.D.1 of the 2007 Interim 

Guidelines, the projected water year release from Lake Powell in 2023 will range from 7.00 

maf (8,630 mcm) to 9.50 maf (11,720 mcm). Because the 2022 operations were intended to 

protect critical elevations at Lake Powell, Reclamation will implement operations to protect 

these critical elevations and preserve the benefits of the 2022 operations in water year 2023. 

Specifically, Reclamation modeled Lower Elevation Balancing Tier operations in WY 2023 as 

follows in the August 24-Month Study: 

• The Glen Canyon Dam annual release has initially been set to 7.00 maf (8,630 mcm), 

and in April 2023 Reclamation will evaluate hydrologic conditions to determine if 

balancing releases may be appropriate under the conditions established in the 2007 

Interim Guidelines

• Balancing releases will be limited (with a minimum of 7.00 maf (8,630 mcm)) to 

protect Lake Powell from declining below elevation 3,525 feet (1,074.42 meters) at the 

end of December 2023 

• Balancing releases will account for operational neutrality of the 0.480 maf (592 mcm) 

that was retained in Lake Powell under the May 2022 action.1 Any Lake Powell 

balancing release volume will be calculated as if the 0.480 maf (592 mcm) had been 

delivered to Lake Mead in WY 2022 

• The modeling approach for WY 2023 will apply to WY 2024 for the purposes of the 

August 24-Month Study 

In accordance with the May 3rd Letter, consistent with the provisions of the 2007 Interim 

Guidelines, and to preserve the benefits to Glen Canyon Dam facilities from 2022 Operations 

into 2023 and 2024, Reclamation will consult with the Basin States on monthly and annual 

operations. Reclamation will also ensure all appropriate consultation with Basin Tribes, the 

56 More information about Lake Powell’s operating decision for water year 2022 is available online: 

https://www.usbr.gov/uc/DocLibrary/Plans/20220503-2022DROA-GlenCanyonDamOperationsDecisionLetter508-DOI.pdf. 

DRAFT
24 2023 AOP – November 22, 2022

Republic of Mexico, other federal agencies, water users and non-governmental organizations 

with respect to implementation of these monthly and annual operations. 

Reclamation will continue to carefully monitor hydrologic and operational conditions and 

assess the need for additional responsive actions and/or changes to operations. Reclamation 

will continue to consult with the Basin States, Basin Tribes, the Republic of Mexico, and other 

partners on Colorado River operations to consider and determine whether additional measures 

should be taken to further enhance the preservation of these benefits, as well as recovery 

protocols, including those of future protective measures for both Lake Powell and Lake Mead.

Maintenance of the eight generating units at Glen Canyon Dam requires them to be taken out of 

service, in pairs, once each year for approximately one month. Additionally, in water years 

2020 through 2023, all four transformers will be replaced, requiring the units to be taken out of 

service, in pairs, and should be completed by the end of calendar year 2023. Reclamation is 

planning to perform maintenance on each of the four hollow jet valves in summer of 2023. 

Outages for annual maintenance and unit replacements are coordinated between Reclamation 

offices in Salt Lake City, Utah, and Page, Arizona, and WAPA to minimize impacts to 

operations. 

Because of less than full storage conditions in Lake Powell resulting from drought in the 

Colorado River Basin, releases from Glen Canyon Dam for dam safety purposes are highly 

unlikely in 2023. If implemented, releases greater than powerplant capacity would be made 

consistent with the 1956 Colorado River Storage Project Act,57 the CRBPA, the LTEMP ROD, 

and the Glen Canyon Dam Operating Criteria. 

Releases from Lake Powell in water year 2023 will continue to reflect consideration of the uses 

and purposes identified in the authorizing legislation for Glen Canyon Dam. Monthly releases 

will also be consistent with the LTEMP ROD and applicable Secretarial decisions and are

updated to be consistent with annual volumes determined pursuant to the 2007 Interim 

Guidelines. 

For the latest monthly projections for Lake Powell, please see the most recent 24-Month Study 

report available on Reclamation’s Upper Colorado Region Water Operations website: 

https://www.usbr.gov/uc/water/crsp/studies/index.html. 

Daily and hourly releases in 2023 will be made according to the parameters of the Glen Canyon 

Dam Operating Criteria. These parameters set the maximum and minimum flows and ramp 

rates within which reservoir releases must be made. Exceptions to these parameters will be 

made in accordance with the Emergency Exception Criteria as described in the Glen Canyon 

Dam Operating Criteria. 

During water year 2023, the Department of the Interior will coordinate planning for 

experimental flows from Glen Canyon Dam in accordance with the 2016 Glen Canyon Dam 

LTEMP ROD. 

57 Available online at: https://www.usbr.gov/lc/region/pao/pdfiles/crspuc.pdf. 

DRAFT
25 2023 AOP – November 22, 2022

Lake Mead

For calendar year 2022, a Shortage Condition was the criterion governing the operation of Lake 

Mead in accordance with Article III(3)(c) of the Operating Criteria, Article II(B)(3) of the 

Consolidated Decree, Section 2.D.1 of the 2007 Interim Guidelines, applicable provisions of 

the LB DCP Agreement, and Sections III.B.1.a and III.B.2.a of Exhibit 1 to the LB DCP 

Agreement. Delivery of water to Mexico was scheduled in accordance with Article 15 of the 

1944 United States-Mexico Treaty and Minutes No. 242, 323, and 327 of the IBWC.

Lake Mead began water year 2022 on October 1, 2021, at elevation 1,067.68 feet (325.43 

meters), with 9.02 maf (11,130 mcm) in storage, which is 35 percent of the conservation 

capacity58 of 26.12 maf (32,220 mcm). Lake Mead ended water year 2022 at elevation

1,045.03 feet (318.53 meters) with 7.33 maf (9,040 mcm) in storage (28 percent of capacity) on 

September 30, 2022. 

The total release from Lake Mead through Hoover Dam during water year 2022 was 8.90 maf 

(10,980 mcm). The total release from Lake Mead through Hoover Dam during calendar year 

2022 is projected to be 8.76 maf (10,810 mcm).

The total inflow into Lake Mead is a combination of water released from Glen Canyon Dam 

plus inflows in the reach between Glen Canyon and Hoover Dams. In water year 2022, inflow 

into Lake Mead was 7.78 maf (9,600 mcm), consisting of 7.00 maf (8,630 mcm) of water 

released from Glen Canyon Dam and 0.776 maf (957 mcm) of inflows between Glen Canyon 

and Hoover Dams. For water year 2023, under the most probable inflow scenario, total inflow 

into Lake Mead is projected to be 7.81 maf (9,630 mcm).

Based on the August 2022 24-Month Study, Lake Mead’s elevation on January 1, 2023, as 

adjusted to reflect operational neutrality as outlined in the Lake Powell operating decision in 

water year 2022, is projected to be 1,047.61 feet (319.31 meters). In accordance with Section 

2.D.1 of the 2007 Interim Guidelines and the applicable provisions of the LB DCP Agreement, 

a Shortage Condition, consistent with Section 2.D.1.b of the 2007 Interim Guidelines, as well 

as Sections III.B.1.a and III.B.2.a of Exhibit 1 to the LB DCP Agreement, respectively, will 

govern the releases and diversions from Lake Mead in calendar year 2023. Releases from Lake 

Mead through Hoover Dam may also be adjusted for the creation and/or delivery of ICS, 

consistent with Section 3 of the 2007 Interim Guidelines and Sections III and IV of Exhibit 1 to

the LB DCP Agreement, in calendar year 2023. 

Under the most probable inflow scenario, Lake Mead is projected to end water year 2023 at 

elevation 1,016.28 feet (309.76 meters), with 5.43 maf (6,700 mcm) in storage (21 percent of 

capacity). Following the end of the water year, Lake Mead is projected to rise to elevation 

1,021.39 feet (311.32 meters) with 5.75 maf (7,090 mcm) in storage (22 percent of capacity) at 

58 Conservation capacity is the amount of space available for water storage between Lake Mead’s water surface 

elevations 895.00 feet (272.80 meters) and 1,219.64 feet (371.75 meters), the start of the exclusive flood control 

space as defined in the Field Working Agreement Between Department of the Interior, Bureau of Reclamation and 

Department of the Army, Corps of Engineers for Flood Control of Hoover Dam and Lake Mead, Colorado River, 

Nevada-Arizona, February 8, 1984.

DRAFT
26 2023 AOP – November 22, 2022

the end of calendar year 2023. The total release from Lake Mead through Hoover Dam during 

water year 2023 is projected to be 8.85 maf (10,920 mcm). The total release from Lake Mead 

through Hoover Dam during calendar year 2023 is projected to be 8.95 maf (11,040 mcm).

The Minimum Probable inflow scenario in the August 2021 24-Month Study activated the 

provision in Section V.B.2 of Exhibit 1 to the LB DCP Agreement requiring consultation 

between the Secretary and the Lower Division States regarding measures to avoid and protect 

against the potential for Lake Mead to decline below 1,020 feet (310.9 meters). These 

consultations resulted in the December 15, 2021 MOU to facilitate near-term actions to 

maintain the water surface elevation at Lake Mead. The 500 Plus Plan aims to generate an 

additional 0.500 maf (617 mcm) of voluntary conservation each year in 2022 and 2023, relative 

to the June 2021 24-Month Study modeling assumptions, in addition to the required shortage 

reductions and DCP contributions under the 2007 Interim Guidelines and Lower Basin DCP 

Agreement, respectively. 

For the latest monthly projections for Lake Mead, please see the most recent 24-Month Study 

report available on Reclamation’s Lower Colorado Region Water Operations website: 

https://www.usbr.gov/lc/region/g4000/24mo/index.html. 

Lake Mohave and Lake Havasu

Lake Mohave started water year 2022 at an elevation of 638.04 feet (194.47 meters) with 1.57 

maf (1,940 mcm) in storage. The water level of Lake Mohave was regulated between elevation 

634.42 feet (193.37 meters) and 643.97 feet (196.28 meters) during the water year, ending at an 

elevation of 639.17 feet (194.82 meters), with 1.60 maf (1,970 mcm) in storage. During water 

year 2022, 8.49 maf (10,470 mcm) was released from Davis Dam. The calendar year 2022 

total release is projected to be 8.34 maf (10,290 mcm).

For water and calendar years 2023, Davis Dam is projected to release nearly the same amount 

of water as in 2022, less any reductions in deliveries and adjustments for the creation and/or 

delivery of ICS. The water level in Lake Mohave will be regulated between an elevation of 

approximately 633.00 feet (192.94 meters) and 645.00 feet (196.60 meters).

Lake Havasu started water year 2022 at an elevation of 448.49 feet (136.70 meters) with 0.590 

maf (728 mcm) in storage. The water level of Lake Havasu was regulated between elevation 

446.38 feet (136.06 meters) and 448.84 feet (136.81 meters) during the water year, ending at an 

elevation of 447.96 feet (136.54 meters), with 0.579 maf (714 mcm) in storage. During water 

year 2022, 6.23 maf (7,680 mcm) was released from Parker Dam. The calendar year 2022 total 

release is projected to be 6.21 maf (7,660 mcm).

For water and calendar years 2023, Parker Dam is expected to release nearly the same amount 

of water as in 2022, less any reductions in deliveries and adjustments for the creation and/or 

delivery of ICS. The water level in Lake Havasu will be regulated between an elevation of 

approximately 446.00 

DRAFT

feet (135.94 meters) and 450.00 feet (137.16 meters).
27 2023 AOP – November 22, 2022

Lakes Mohave and Havasu are scheduled to be drawn down in the late summer and fall months 

to provide storage space for local storm runoff and will be filled in the winter to meet higher 

summer water needs. This drawdown also corresponds with normal maintenance at both Davis 

and Parker powerplants scheduled for October through May. 

Bill Williams River

Alamo Lake elevation and storage decreased during water year 2022. Alamo Lake started

water year 2022 at elevation 1,113.40 feet (339.36 meters) with 0.100 maf (123 mcm) in 

storage and ended water year 2022 at elevation 1,110.24 feet (338.40 meters) with 0.091 maf 

(112.74 mcm) in storage. In water year 2022, average daily releases from Alamo Lake were

about 25 cfs (0.71 cms). Water released from Alamo Lake totaled 0.018 maf (22 mcm) for 

water year 2022. 

Senator Wash and Laguna Reservoirs

Senator Wash Reservoir is an off-stream regulating storage facility below Parker Dam 

(approximately 142 river miles downstream) and has a storage capacity of 0.014 maf (17 mcm) 

at full pool elevation of 251.00 feet (76.50 meters). The reservoir is used to store excess flows 

from the river caused by water user cutbacks, side wash inflows due to rain, and other factors. 

Stored waters are utilized to meet the water demands in Arizona and California and the delivery 

obligation to Mexico. 

Since 1992, elevation restrictions have been in place on Senator Wash Reservoir due to 

potential piping and liquefaction of foundation and embankment materials at West Squaw Lake 

Dike and Senator Wash Dam. Senator Wash Reservoir is restricted to an elevation of 240.00 

feet (73.15 meters) with 0.0090 maf (11 mcm) of storage, a loss of about 0.0050 maf (6.2 mcm) 

of storage from its original capacity. Senator Wash Reservoir must not exceed an elevation of 

238.00 feet (72.54 meters) for more than 10 consecutive days. This reservoir restriction is 

expected to continue through 2023. 

Laguna Reservoir is a regulating storage facility located approximately five river miles 

downstream of Imperial Dam and is primarily used to capture sluicing flows from Imperial 

Dam. The storage capability of Laguna Reservoir has diminished from about 0.0015 maf (1.9 

mcm) to approximately 0.0004 maf (0.5 mcm) due to sediment accumulation and vegetation 

growth. Sediment accumulation in the reservoir has occurred primarily due to flood releases 

that occurred in 1983 and 1984, and flood control or space building releases that occurred 

between 1985 and 1988 and from 1997 through 1999. 

Sediment removal at Laguna Reservoir to reestablish operational sluicing began in 2013; 

however, the project was put on hold until a dredging project at Imperial Dam is completed. 

The revised estimated completion date is after 2024. In total, the Laguna Basin Dredging 

project will dredge approximately 3.55 million cubic yards (2.7 mcm) of sediment, 

reestablishing 140 acres (0.57 square kilometers) of open water. As of October 2022, 

approximately 2.72 million cubic yards (2.1 mcm) of material have been removed. All dredged 

material has been disposed of in a designated area adjacent to the project site. The project has 

incorporated the use of both land-based and waterborne heavy equipment. The project permit 

DRAFT
28 2023 AOP – November 22, 2022

was obtained from the United States Army Corps of Engineers (USACE) in May 2013 and was 

valid through May 2020. The project permit from the USACE may be extended after the 

completion of the Imperial Dam dredging project.

Imperial Dam

Imperial Dam is the last major diversion dam on the Colorado River in the United States. From 

the head works at Imperial Dam, water is diverted into the All-American Canal on the 

California side of the dam and into the Gila Gravity Main Canal on the Arizona side of the 

dam. These diversions provide water to the Gila Project, the Yuma Project, the Imperial 

Irrigation District (IID), the Coachella Valley Water District, and the City of Yuma, and 

through Siphon Drop and Pilot Knob to the Northerly International Boundary (NIB) for 

diversion at Morelos Dam by Mexico. Flows arriving at Imperial Dam for calendar year 2022 

are projected to be 5.53 maf (6,820 mcm). The flows arriving at Imperial Dam for calendar 

year 2023 are projected to be 5.30 maf (6,540 mcm). 

Reclamation started a dredging project above Imperial Dam in March 2021. The purpose of 

this project is to remove sediment deposited immediately upstream of Imperial Dam that

threatens to constrict and/or prevent the operation of Imperial Dam facilities. Large amounts of 

sediment deposits are detrimental to Imperial Dam water operations. Excessive sediment build 

up in the reservoir limits reservoir storage capacity and can impede gate operations. Periodic 

removal of sediment is necessary to allow delivery of water to the Gila Gravity Main Canal and 

the All-American canal. This project has been extended to remove an additional 0.300 million 

cubic yards (0.230 mcm) and is scheduled to be completed in 2023. As of October 2022, 

approximately 0.739 million cubic yards (0.565 mcm) of material have been removed. The 

project permit was obtained from the USACE and is valid through 2025. 

Gila River Flows

During water year 2022, there was below average snowfall in the Gila River Basin, including 

the Salt and Verde River watersheds. The Salt River Project did not release water from its 

system in excess of diversion requirements at Granite Reef Diversion Dam in water year 2022. 

No water reached or was released from Painted Rock Dam by the USACE in water year 2022. 

Warren H. Brock Reservoir

The Warren H. Brock (Brock) Reservoir is located near the All-American Canal in Imperial 

County, California. The purpose of the 0.0080 maf (9.9 mcm) Brock Reservoir is to reduce 

non-storable flows and to enhance beneficial use of Colorado River water within the United 

States. The reservoir reduces the impact of loss of water storage at Senator Wash due to 

operational restrictions and provides additional regulatory storage, allowing for more efficient 

management of water below Parker Dam. In 2021, Reclamation completed the Warren H. 

Brock Reservoir Conservation Summary Report which includes, among other matters, a 

summary of water conserved by Brock Reservoir from 2013 through 2019.59 Water conserved 

59 Available online at: https://www.usbr.gov/lc/region/programs/strategies/agreements/BrockReport.pdf. 

DRAFT
29 2023 AOP – November 22, 2022

by Brock Reservoir in 2020 and 2021 may be found in the respective annual Colorado River 

Accounting and Water Use Report, Arizona, California, and Nevada.60

Yuma Desalting Plant 

The Yuma Desalting Plant (YDP) was authorized in 1974 under the Colorado River Basin 

Salinity Control Act (Public Law 93-320)61 which authorized the federal government to 

construct the YDP to desalt the drainage flows from the Wellton-Mohawk Division of the Gila 

Project. This would allow the treated water to be delivered to Mexico as part of its 1944 

United States-Mexico Water Treaty allotment. The United States has met salinity requirements 

established in IBWC Minute No. 242 primarily through use of a canal to bypass WelltonMohawk drain water to the Ciénega de Santa Clara, a wetland of open water, vegetation, and 

mudflats within a Biosphere Reserve in Mexico. In calendar year 2022, the amount of water 

discharged from the Wellton-Mohawk Division through the bypass canal is anticipated to be 

0.114 maf (140 mcm) measured at gaging station 0+00 and 0.118 maf (146 mcm) measured at 

the gaging station near the Southerly International Boundary (SIB), at an approximate 

concentration of total dissolved solids of 2,456 parts per million (ppm). 

Off-stream Storage Agreements

Colorado River water may be stored off-stream pursuant to individual SIRAs and 43 CFR Part 

414 within the Lower Division States. The Secretary shall make ICUA available to contractors 

in Arizona, California, or Nevada pursuant to individual SIRAs and 43 CFR Part 414. The 

Southern Nevada Water Authority (SNWA) may propose to make unused Nevada basic 

apportionment available for storage by the Metropolitan Water District of Southern California 

(MWD)62 and/or Arizona Water Banking Authority (AWBA)63 in calendar years 2022 and 

2023. 

Intentionally Created Surplus

The 2007 Interim Guidelines included the adoption of the ICS mechanism that, among other 

things, encourages the efficient use and management of Colorado River water in the Lower 

Basin. ICS may be created through several types of activities that include improvements in 

system efficiency, extraordinary conservation, tributary conservation, and the importation of 

non-Colorado River System water into the Colorado River mainstream over the course of a 

calendar year. Several implementing agreements64 were executed concurrent with the issuance 

60 Available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 61 Available online at: https://www.usbr.gov/lc/region/pao/pdfiles/crbsalct.pdf. 62 Storage and Interstate Release Agreement among The United States of America, acting through the Secretary of 

the Interior; The Metropolitan Water District of Southern California; the Southern Nevada Water Authority; and 

the Colorado River Commission of Nevada, October 21, 2004. Available online at: 

https://www.usbr.gov/lc/region/g4000/contracts/SNWA_MWDSIRAfinal.pdf. 63 Storage and Interstate Release Agreement among The United States of America, acting through the Secretary of 

the Interior; The Arizona Water Banking Authority; the Southern Nevada Water Authority; and the Colorado 

River Commission of Nevada, December 18, 2002. Available online at: 

https://www.usbr.gov/lc/region/g4000/contracts/SIRAfinal.pdf. 64 Information on forbearance and delivery agreements related to the creation and delivery of ICS can be found at: 

https://www.usbr.gov/lc/region/programs/strategies/documents.html. 

DRAFT
30 2023 AOP – November 22, 2022

of the ROD for the 2007 Interim Guidelines. The LB DCP Agreement, as authorized by Public 

Law 116-14 through the 2019 Colorado River DCP, expanded upon the ICS concept, including 

the execution of additional implementation agreements65 and establishment of a DCP ICS 

category. ICS credits may be created and delivered in calendar years 2022 and 2023 pursuant 

to Section 3 of the 2007 Interim Guidelines, Sections III and IV of Exhibit 1 to the LB DCP 

Agreement, and the implementing agreements. ICS balances by state, user, and type of ICS 

may be found in the annual Colorado River Accounting and Water Use Report, Arizona, 

California, and Nevada.66 

IBWC Minute No. 323 identified cooperative measures that the United States and Mexico will 

take through December 31, 2026, including water conservation projects in Mexico. Consistent 

with Section IX.A of IBWC Minute No. 323, these water conservation projects will generate or 

conserve a volume of water of which 0.109 maf (135 mcm) will be converted to Binational ICS 

for use in the United States and 0.050 maf (62 mcm) will be allocated to the system for the 

benefit of all users.

Extraordinary Conservation ICS. Entities with approved plans may create Extraordinary 

Conservation ICS in 2022 and/or 2023. Table 5 provides a summary of anticipated, submitted, 

or approved Extraordinary Conservation ICS plans of creation in 2022 and 2023. Entities with 

available Extraordinary Conservation ICS may request delivery of ICS credits in 2022 and 

202367. 

65 Information on the agreements related to the creation of ICS under the LB DCP Agreement can be found at:

https://www.usbr.gov/lc/region/programs/dcp.html. 66 Available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 67 The ICS delivery volumes will be reflected in Reclamation’s water accounting report. The water accounting 

report is available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 

DRAFT
31 2023 AOP – November 22, 2022

Table 5. Summary of Extraordinary Conservation ICS Plans of Creation

in Calendar Years 2022 and 2023 

Entity 2022 Plan 

of Creation

Status of 

2022 Plan

2023 Plan 

of Creation

Status of 

2023 Plan

CAWCD up to 0.100 maf

(123 mcm) approved up to 0.100 maf (123 mcm) submitted

Gila River Indian 

Community

up to 0.079 maf 

(97 mcm) approved -- --

IID up to 0.062 maf 

(76 mcm) approved up to 0.062 maf (76 mcm) submitted

MWD up to 0.450 maf 

(555 mcm) approved up to 0.450 maf (555 mcm) submitted

SNWA up to 0.100 maf 

(123 mcm) approved up to 0.100 maf (123 mcm) submitted

System Efficiency ICS. In 2022 and 2023, the Central Arizona Water Conservation District 

(CAWCD), MWD, and SNWA may request delivery of Brock Reservoir System Efficiency 

ICS credits. The annual maximum delivery of Brock Reservoir System Efficiency ICS is 0.065 

maf (80 mcm). In 2022 and 2023, CAWCD, MWD, and SNWA may request delivery of YDP 

Pilot Run System Efficiency ICS credits. 

Tributary Conservation ICS. SNWA has an approved plan to create up to 0.043 maf (53 

mcm) of Tributary Conservation ICS in 2022 and has submitted a plan to create up to 0.044 

maf (54 mcm) in 2023. Any Tributary Conservation ICS not delivered for use by SNWA in the 

calendar year created will, at the beginning of the following year, be converted to Extraordinary 

Conservation ICS pursuant to the 2007 Interim Guidelines.

Imported ICS. SNWA may submit plans to create Imported ICS in 2022 and 2023. Any 

Imported ICS not delivered for use by SNWA in the calendar year created will, at the

beginning of the following year, be converted to Extraordinary Conservation ICS pursuant to 

the 2007 Interim Guidelines. 

Binational ICS. In 2022 and 2023, CAWCD, IID, MWD, and SNWA may request delivery of 

Binational ICS subject to any applicable provisions in the delivery agreements. 

DCP ICS. DCP ICS may be created in 2022 and 2023 by entities making DCP contributions

consistent with Section III of Exhibit 1 to the LB DCP Agreement. Following creation, DCP 

ICS may be delivered in a subsequent year in accordance with Section III.F of Exhibit 1 to the 

LB DCP Agreement.

DRAFT
32 2023 AOP – November 22, 2022

System Conservation

System conservation agreements have allowed water users to participate in projects designed to 

determine whether voluntary, temporary, and compensated programs to conserve or reduce 

consumptive use of Colorado River water can benefit the entire Colorado River system by 

mitigating the effect on declining storage levels in Colorado River reservoirs.68,69 Agreements 

previously executed under the PSCP in the Lower Basin continue to be implemented in 2022 

and 2023.70 

Consistent with the Secretary’s efforts to create or conserve 0.100 maf (123 mcm) or more of 

Colorado River system water annually in the Lower Basin under the LB DCP Agreement and 

the additional conservation goals under the 500 Plus Plan MOU, Reclamation and the MOU 

parties have entered into agreements to create system conservation water consistent with these 

two agreements. A summary of agreements implemented in calendar years 2022 and 2023 are

shown in Table 6. 

68 For the period from 2015 through 2018, the UCRC acted as the contracting entity for the System Conservation 

Pilot Program (SCPP) in the Upper Basin. In June 2018, the UCRC passed a resolution to temporarily cease to act 

as the contracting entity for the SCPP after fulfilling its commitments for 2018. The June 20, 2018 Resolution of 

the UCRC is available online at: 

http://www.ucrcommission.com/RepDoc/SCPPDocuments/DemandMgmtResolution062018.pdf. 69 Pursuant to Public Law 113-235, a report from the Secretary evaluating the effectiveness of the water 

conservation pilot projects was submitted to Congress, including a recommendation that the activities undertaken 

by the pilot projects should be continued. More information is available online at: 

https://www.usbr.gov/lc/region/programs/PilotSysConsProg/report_to_congressW_appendices2021.pdf. 70 More information on the PSCP in the Lower Basin can be found at: 

https://www.usbr.gov/lc/region/programs/PilotSysConsProg/pilotsystem.html. 

DRAFT
33 2023 AOP – November 22, 2022

Table 6. Summary of Projected System Conservation in the Lower Basin for Calendar Years 

2022 and 2023 

Entity/Project 2022

Volume

2023 

Volume

Agreement or 

Program Funder(s)

U.S. Funded 

2022 

Volume71

U.S. Funded 

2023 

Volume

242 Wellfield 

Expansion

0.013 maf

(16 mcm)

0.017 maf

(21 mcm)

LB DCP 

Agreement Reclamation 0.013 maf(16 mcm)

0.017 maf

(21 mcm)

Colorado 

River Indian 

Tribes

0.050 maf

(62 mcm) --

Arizona LB DCP 

Framework 

Agreement

-- -- --

Colorado 

River Indian 

Tribes

0.005 maf

(6 mcm) --

500 Plus Plan

LB DCP 

Agreement

Reclamation 0.005maf

(6 mcm) --

Fort 

McDowellYavapai 

Nation

0.014 maf

(17 mcm) -- LB DCP Agreement Reclamation 0.014 maf(17 mcm) --

Gila River 

Indian 

Community

0.051 maf

(63 mcm) --

500 Plus Plan

LB DCP 

Agreement

Reclamation 0.051 maf

(63 mcm) --

Central 

Arizona 

Project 

Contractors

0.0945 maf

(117 mcm) --

500 Plus Plan

LB DCP 

Agreement

Reclamation, 

ADWR, 

CAWCD, and 

SNWA

0.064 maf

(79 mcm) --

Yuma Mesa 

Irrigation and 

Drainage 

District

0.009 maf

(11 mcm)

0.014 maf 

(17 mcm)

500 Plus Plan

LB DCP 

Agreement

Reclamation, 

ADWR, 

CAWCD, and 

SNWA

0.001 maf

(1 mcm)

0.002 maf

(2 mcm)

Mohave 

Valley 

Irrigation and 

Drainage 

District

0.0096 maf

(12 mcm)

0.0096 maf 

(12 mcm)

500 Plus Plan

LB DCP 

Agreement

Reclamation, 

ADWR, 

CAWCD, 

MWD, and 

SNWA

0.001 maf

(1 mcm)

0.001 maf

(1 mcm)

MWD-PVID 

Forbearance 

and Fallowing 

Program

0.051 maf

(63 mcm)

0.058 maf

(72 mcm)

500 Plus Plan

LB DCP 

Agreement

Reclamation, 

CAWCD, 

MWD, and 

SNWA

0.025 maf

(31 mcm)

0.029 maf

(36 mcm)

71 The U.S. funded portion of the agreement volume is counted towards the Secretary’s efforts to create or 

conserve 0.100 maf (123 mcm) or more of Colorado River system water annually in the Lower Basin under the LB 

DCP Agreement.

DRAFT
34 2023 AOP – November 22, 2022

Additional projects or agreements to create or conserve system water in the Lower Basin may 

also be implemented in calendar years 2022 and/or 2023. 

Delivery of Water to Mexico

Delivery of water to Mexico pursuant to the 1944 United States-Mexico Water Treaty and 

IBWC Minute No. 323 is anticipated to be 1.45 maf (1,790 mcm) in calendar year 2022. This 

volume reflects a shortage reduction of 0.050 maf (62 mcm) pursuant to Section III.A of IBWC 

Minute No. 323, a water savings contribution of 0.030 maf (37 mcm) as required by Mexico 

under Section IV of IBWC Minute No. 323, the creation of approximately 0.002 maf (2.5 

mcm) of water for Mexico’s Water Reserve pursuant to Section V of IBWC Minute No. 323, 

and the delivery of approximately 0.035 maf (43 mcm) of water from Mexico’s Water Reserve 

for environmental purposes72 in accordance with IBWC Minute No. 323 Section V and 

accordingly with Section VIII and IX regarding the commitment of the United States’ share of 

water for the environment. The water savings contribution volume shall be accounted for as 

described in the Joint Report of the Principal Engineers with the Implementing Details of the 

Binational Water Scarcity Contingency Plan in the Colorado River Basin (2019 Joint 

Engineers’ Report).73 Balances of Mexico’s Water Reserve in previous years may be found in 

the annual Colorado River Accounting and Water Use Report, Arizona, California, and 

Nevada.74

Of the scheduled delivery to Mexico in calendar year 2022, approximately 1.310 maf (1,620 

mcm) is projected to be delivered at NIB and approximately 0.140 maf (173 mcm) is projected 

to be delivered at SIB. Under IBWC Minute No. 327 and the Emergency Delivery 

Agreement,75 Mexico, through the IBWC, may request water to be delivered to Tijuana, Baja 

California, through MWD, the San Diego County Water Authority, and the Otay Water 

District’s respective distribution system facilities in California. In calendar year 2022, 

approximately 3,465 acre-feet (4.3 mcm) is scheduled to be delivered to Tijuana, Baja 

California.

Of the total delivery at SIB projected in calendar year 2022, approximately 0.081 maf (100 

mcm) is projected to be delivered from the Yuma Project Main Drain and approximately 0.052 

maf (64 mcm) is expected to be delivered by the Protective and Regulatory Pumping Unit (242 

well field).

Excess flows arriving at the NIB are anticipated to be approximately 0.014 maf (17 mcm) in 

calendar year 2022. Excess flows result from a combination of factors, including heavy rain 

from seasonal storms, water ordered but not delivered to United States users downstream of 

72 More information is available in the 2021 Joint Engineers’ Report online at: 

https://www.ibwc.gov/Files/Min323_joint_report_eng.pdf. 73 Joint Report of the Principal Engineers with the Implementing Details of the

Binational Water Scarcity Contingency Plan in the Colorado River Basin. Available online at: 

https://www.ibwc.gov/Files/joint_report_min323_bi_water_scarcity_contingency_plan_final.pdf. 74 Available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 75 Agreement for Temporary Emergency Delivery of a Portion of the Mexican Treaty Waters of the Colorado 

River to the International Boundary in the Vicinity of Tijuana, Baja California, Mexico, and for Operation of 

Facilities in the United States, dated February 8, 2022.

DRAFT
35 2023 AOP – November 22, 2022

Parker Dam, inflows into the Colorado River below Parker Dam, and spills from irrigation 

facilities below Imperial Dam. 

Pursuant to the 1944 United States-Mexico Water Treaty and Section III.A of IBWC Minute 

No. 323, a volume of 1.430 maf (1,760 mcm) will be available to be scheduled for delivery to 

Mexico in calendar year 2023. This volume may be further adjusted for water savings 

contributions as required under Section IV of IBWC Minute No. 323. Mexico may create 

water for or take delivery of water from Mexico’s Water Reserve pursuant to Section III.C and 

Section V of IBWC Minute No. 323. Approximately 0.140 maf (173 mcm) is projected to be 

delivered at SIB and the remainder of the water to be scheduled for delivery to Mexico in 2023 

will be delivered at NIB. Under IBWC Minute No. 327 and the Emergency Delivery 

Agreement, water may be delivered to Tijuana through MWD, the San Diego County Water 

Authority, and the Otay Water District’s respective distribution system facilities in California.

Drainage flows to the Colorado River from the South Gila Drain Pump Outlet Channels and the 

Yuma Mesa Conduit are projected to be 0.003 maf (3 mcm) and 0.031 maf (38.6 mcm), 

respectively, for calendar year 2022. Consistent with Articles 11 and 15 of the 1944 United 

States-Mexico Water Treaty and IBWC Minute No. 242, this water is available for delivery at 

NIB in satisfaction of the 1944 United States-Mexico Water Treaty. 

As stated in IBWC Minute No. 242, water delivered to Mexico upstream of Morelos Dam shall 

have an annual average salinity of no more than 115 ppm ± 30 ppm United States’ count (121 

ppm ± 30 ppm Mexican count) over the annual average salinity of Colorado River waters 

which arrive at Imperial Dam. This difference, known as the salinity differential, is projected 

to be 140 ppm by the United States’ count for calendar year 2022. 

Mexico has identified four critical months for agriculture, September through December, 

regarding improving the quality of water delivered at SIB. Consistent with Section VI.B of 

IBWC Minute No. 323, the United States has improved the water quality delivered at the SIB 

to approximately 1,200 ppm during this four-month period. 

DRAFT
36 2023 AOP – November 22, 2022

2023 DETERMINATIONS

The AOP provides projections regarding reservoir storage and release conditions during the 

upcoming year, based upon Congressionally mandated and authorized storage, release, and 

delivery criteria and determinations. After meeting these criteria and determinations, specific 

reservoir releases may be modified within these requirements as forecasted inflows change in 

response to climatic variability and to provide additional benefits coincident to the projects’ 

multiple purposes. 

Upper Basin

Section 602(a) of the CRBPA provides for the storage of Colorado River water in Upper Basin 

reservoirs and the release of water from Lake Powell that the Secretary finds reasonably 

necessary to assure deliveries to comply with Articles III(c), III(d), and III(e) of the 1922 

Colorado River Compact without impairment to the annual consumptive use in the Upper 

Basin. The Operating Criteria provide that the annual plan of operation shall include a 

determination of the quantity of water considered necessary to be in Upper Basin storage at the 

end of the water year after taking into consideration all relevant factors including historic 

streamflows, the most critical period of record, the probabilities of water supply, and estimated 

future depletions. Water not required to be so stored will be released from Lake Powell:

• to the extent it can be reasonably applied in the States of the Lower Division to the uses 

specified in Article III(e) of the 1922 Colorado River Compact, but these releases will 

not be made when the active storage in Lake Powell is less than the active storage in 

Lake Mead

• to maintain, as nearly as practicable, active storage in Lake Mead equal to the active 

storage in Lake Powell 

• to avoid anticipated spills from Lake Powell

Taking into consideration all relevant factors required by Section 602(a)(3) of the CRBPA and 

the Operating Criteria, it is determined that the active storage in Upper Basin reservoirs 

projected for September 30, 2022 under the most probable inflow scenario would be below the 

threshold required under Section 602(a) of the CRBPA. 

Taking into account (1) the existing water storage conditions in the basin, (2) the August 2022 

24-Month Study projection of the most probable near-term water supply conditions in the 

basin, (3) the concept of operational neutrality as outlined in the Lake Powell annual operating 

decision in water year 2022,76 (4) the concept of preserving the benefits to Glen Canyon Dam 

facilities and operations in 2023 of the operating decisions made in water year 2022,76 and (5) 

Section 6.D.1 of the 2007 Interim Guidelines, the Lower Elevation Balancing Tier will govern 

the operation of Lake Powell for water year 2023. Subject to decisions regarding preservation 

76 More information about Lake Powell’s operating decision for water year 2022 is available online: 

https://www.usbr.gov/uc/DocLibrary/Plans/20220503-2022DROA-GlenCanyonDamOperationsDecisionLetter508-DOI.pdf. 

DRAFT
37 2023 AOP – November 22, 2022

of the benefits to Glen Canyon Dam facilities and operations, the August 2022 24-Month Study 

of the most probable inflow scenario projects the water year 2023 release from Glen Canyon 

Dam to be 7.00 maf (8,630 mcm). Given the hydrologic variability of the Colorado River 

System and consistent with Section 6.D.1 of the 2007 Interim Guidelines, the projected water 

year release from Lake Powell in 2023 will range from 7.00 maf (8,630 mcm) to 9.50 maf 

(11,720 mcm). Because the 2022 operations were intended to protect critical elevations at Lake 

Powell, Reclamation will implement operations to protect these critical elevations and preserve 

the benefits of the 2022 operations in water year 2023. Specifically, Reclamation modeled 

Lower Elevation Operating Tier operations in WY 2023 as follows in the August 24-Month 

Study: 

• The Glen Canyon Dam annual release has initially been set to 7.00 maf (8,630 mcm), 

and in April 2023 Reclamation will evaluate hydrologic conditions to determine if 

balancing releases may be appropriate under the conditions established in the 2007 

Interim Guidelines

• Balancing releases will be limited (with a minimum of 7.00 maf (8,630 mcm)) to 

protect Lake Powell from declining below elevation 3,525 feet (1,074.42 meters) at the 

end of December 2023 

• Balancing releases will account for operational neutrality of the 0.480 maf (592 mcm) 

that was retained in Lake Powell under the May 2022 action. Any Lake Powell 

balancing release volume will be calculated as if the 0.480 (592 mcm) maf had been 

delivered to Lake Mead in WY 2022 

• The modeling approach for WY 2023 will apply to 2024 for purposes of the August 24-

Month Study 

In accordance with the May 3rd Letter, and consistent with the provisions of the 2007 Interim 

Guidelines, and to preserve the benefits to Glen Canyon Dam facilities from 2022 Operations 

into 2023 and 2024, Reclamation will continue to consult with the Basin States on monthly and 

annual operations. Reclamation will also consult with Basin Tribes, the Republic of Mexico, 

other federal agencies, water users and non-governmental organizations with respect to 

implementation of these monthly and annual operations. 

Reclamation will continue to carefully monitor hydrologic and operational conditions and 

assess the need for additional responsive actions and changes to operations. Reclamation will 

continue to consult with the Basin States, Basin Tribes, the Republic of Mexico, and other 

partners on Colorado River operations to consider and determine whether additional measures 

should be taken to further enhance the preservation of these benefits, as well as recovery 

protocols, including those of future protective measures for both Lake Powell and Lake Mead.

Lower Basin

Pursuant to Article III of the Operating Criteria and consistent with the Consolidated Decree, 

water shall be released or pumped from Lake Mead to meet the following requirements:

(a) 1944 United States-Mexico Water Treaty obligations;

(b) Reasonable beneficial consumptive use requirements of mainstream users in the Lower 

Division States;

DRAFT
38 2023 AOP – November 22, 2022

(c) Net river losses;

(d) Net reservoir losses;

(e) Regulatory wastes; and

(f) Flood control. 

The Operating Criteria provide that after the commencement of delivery of mainstream water 

by means of the Central Arizona Project, the Secretary will determine the extent to which the 

reasonable beneficial consumptive use requirements of mainstream users are met in the Lower 

Division States. Reasonable beneficial consumptive use requirements are met depending on 

whether a Normal, Surplus, or Shortage Condition has been determined. The Normal 

Condition is defined as annual pumping and release from Lake Mead sufficient to satisfy 7.50

maf (9,250 mcm) of consumptive use in accordance with Article III(3)(a) of the Operating 

Criteria and Article II(B)(1) of the Consolidated Decree. The Surplus Condition is defined as 

annual pumping and release from Lake Mead sufficient to satisfy in excess of 7.50 maf (9,250 

mcm) of consumptive use in accordance with Article III(3)(b) of the Operating Criteria and 

Article II(B)(2) of the Consolidated Decree. An ICS Surplus Condition is defined as a year in 

which Lake Mead’s elevation is projected to be above elevation 1,075.00 feet (327.66 meters) 

on January 1, a Flood Control Surplus has not been determined, and delivery of ICS has been 

requested. The Secretary may determine an ICS Surplus Condition in lieu of a Normal 

Condition or in addition to other operating conditions that are based solely on the elevation of 

Lake Mead. The Shortage Condition is defined as annual pumping and release from Lake 

Mead insufficient to satisfy 7.50 maf (9,250 mcm) of consumptive use in accordance with 

Article III(3)(c) of the Operating Criteria and Article II(B)(3) of the Consolidated Decree.

The 2007 Interim Guidelines are being utilized in calendar year 2023 and serve to implement 

the narrative provisions of Article III(3)(a), Article III(3)(b), and Article III(3)(c) of the 

Operating Criteria and Article II(B)(1), Article II(B)(2), and Article II(B)(3) of the 

Consolidated Decree for the period through 2026. The 2007 Interim Guidelines will be used 

annually by the Secretary to determine the quantity of water available for use within the Lower 

Division States.

Consistent with the 2007 Interim Guidelines and the LB DCP Agreement, and taking into 

consideration the concept of operational neutrality as outlined in the Lake Powell operating 

decision in water year 2022, the August 2022 24-Month Study was used to forecast the system 

storage as of January 1, 2023. Based on a projected January 1, 2023 Lake Mead elevation, as 

adjusted to reflect operational neutrality as outlined in the Lake Powell operating decision in 

water year 2022, of 1,047.61 feet (319.31 meters) and consistent with Section 2.D.1 of the 2007 

Interim Guidelines, a Shortage Condition, consistent with Section 2.D.1.b, will govern releases 

for use in the states of Arizona, Nevada, and California during calendar year 2023 in 

accordance with Article III(3)(c) of the Operating Criteria and Article II(B)(3) of the 

Consolidated Decree. In addition, consistent with Sections III.B.1.a and III.B.2.a of Exhibit 1 

to the LB DCP Agreement, DCP contributions will be required by Arizona and Nevada, 

respectively, in calendar year 2023. Water deliveries in the Lower Basin during calendar year 

2023 will be limited to 7.083 maf (8,730 mcm) and will be further adjusted for DCP 

contributions and creation and/or delivery of ICS credits and/or DSS. 

DRAFT
39 2023 AOP – November 22, 2022

Article II(B)(6) of the Consolidated Decree allows the Secretary to allocate water that is 

apportioned to one Lower Division State but is for any reason unused in that state to another 

Lower Division State. This determination is made for one year only, and no rights to recurrent 

use of the water accrue to the state that receives the allocated water. No unused apportionment 

for calendar year 2023 is anticipated. If any unused apportionment becomes available after 

adoption of this AOP, Reclamation, on behalf of the Secretary, may allocate any such available 

unused apportionment for calendar year 2023 in accordance with Article II(B)(6) of the 

Consolidated Decree, the Unused Water Policy, and giving further consideration to the water 

conservation objectives of the July 30, 2014 agreement for the PSCP, the December 15, 2021 

MOU to maintain the elevation of Lake Mead, and as specified in Section 4.b of the LB DCP 

Agreement. 

In calendar year 2023, water may be stored off-stream pursuant to individual SIRAs and 43 

CFR Part 414 within the Lower Division States. The Secretary shall make ICUA available to 

contractors in Arizona, California, or Nevada pursuant to individual SIRAs and 43 CFR Part 

414. SNWA may propose to make unused Nevada basic apportionment available for storage 

by MWD and/or AWBA in calendar year 2023. 

The IOPP, which became effective January 1, 2004, will be in effect during calendar year 2023. 

In accordance with Section 2.6.e of the IOPP, further accumulation of inadvertent overruns in 

calendar year 2023 will be suspended. Payback balances by state and user may be found in the 

annual Colorado River Accounting and Water Use Report, Arizona, California, and Nevada.77

In calendar year 2023, conserved Colorado River water, created through the PSCP and other 

voluntary agreements, is anticipated to be added to system reservoirs in the Lower Basin

pursuant to system conservation agreements. 

The 2007 Interim Guidelines included the adoption of the ICS mechanism, which was 

expanded upon in the LB DCP Agreement, that among other things encourages the efficient use 

and management of Colorado River water in the Lower Basin. In calendar year 2023, ICS 

credits will be created and delivered pursuant to Section 3 of the 2007 Interim Guidelines, 

Sections III and IV of Exhibit 1 to the LB DCP Agreement, and appropriate forbearance and 

delivery agreements.

Consistent with Section 4 of the 2007 Interim Guidelines, DSS may be created and delivered in 

calendar year 2023. 

 

Given the limitation of available supply and recent low inflow amounts within the Colorado 

River Basin, the Secretary, through Reclamation, will continue to review Lower Basin 

operations to assure that all deliveries and diversions of mainstream water are in strict 

accordance with the Consolidated Decree, applicable statutes, contracts, rules, and agreements.

As provided in Section 7.C of the 2007 Interim Guidelines, the Secretary may undertake a midyear review to consider revisions of the current AOP. For Lake Mead, the Secretary shall 

77 Available online at: https://www.usbr.gov/lc/region/g4000/wtracct.html. 

DRAFT
40 2023 AOP – November 22, 2022

revise the determination in any mid-year review for the current year only to allow for additional 

deliveries from Lake Mead pursuant to Section 7.C of the 2007 Interim Guidelines.

1944 United States-Mexico Water Treaty

Under the minimum probable, most probable, and maximum probable inflow scenarios, water 

in excess of that required to supply uses in the United States and the guaranteed quantity of 

1.500 maf (1,850 mcm) allotted to Mexico will not be available, subject to any increased 

amounts delivered consistent with Section V of IBWC Minute No. 323. Vacant storage space 

in mainstream reservoirs is substantially greater than that required by flood control regulations. 

A volume of 1.430 maf (1,760 mcm) of water will be available to be scheduled for delivery to 

Mexico during calendar year 2023 subject to and in accordance with Article 15 of the 1944 

United States-Mexico Water Treaty, IBWC Minutes No. 242 and 327, and Section III.A of 

IBWC Minute No. 323. This volume may be further adjusted for water savings contributions 

as required under Section IV of IBWC Minute No. 323, as detailed in the 2019 Joint Engineers’ 

Report. In accordance with Section III.C and Section V of IBWC Minute No. 323, Mexico 

may create water for or take delivery of water from Mexico’s Water Reserve. 

Calendar year schedules of the monthly deliveries of Colorado River water are formulated by 

the Mexican Section of the IBWC and presented to the United States Section before the 

beginning of each calendar year. Changes to these delivery schedules are coordinated between 

the United States and Mexican Sections of the IBWC pursuant to Article 15 of the 1944 United 

States-Mexico Water Treaty and consistent with other applicable agreements. 

DRAFT
41 2023 AOP – November 22, 2022

DISCLAIMER

Nothing in this AOP is intended to interpret the provisions of the Colorado River Compact (45 

Stat. 1057); the Upper Colorado River Basin Compact (63 Stat. 31); the Utilization of Waters 

of the Colorado and Tijuana Rivers and of the Rio Grande, Treaty Between the United States of 

America and Mexico (Treaty Series 994, 59 Stat. 1219); the United States/Mexico agreements 

in Minute No. 242 of August 30, 1973 (Treaty Series 7708; 24 UST 1968), Minute No. 323 of 

September 21, 2017, or Minute No. 327 of January 28, 2022; the Consolidated Decree entered 

by the Supreme Court of the United States in Arizona v. California (547 U.S 150 (2006)); the 

Boulder Canyon Project Act (45 Stat. 1057; 43 U.S.C. 617); the Boulder Canyon Project 

Adjustment Act (54 Stat. 774; 43 U.S.C. 618a); the Colorado River Storage Project Act (70 

Stat. 105; 43 U.S.C. 620); the Colorado River Basin Project Act (82 Stat. 885; 43 U.S.C. 1501); 

the Colorado River Basin Salinity Control Act (88 Stat. 266; 43 U.S.C. 1951); the Hoover 

Power Plant Act of 1984 (98 Stat. 1333); the Hoover Power Allocation Act of 2011 (125 Stat. 

777); the Colorado River Floodway Protection Act (100 Stat. 1129; 43 U.S.C. 1600); the Grand 

Canyon Protection Act of 1992 (Title XVIII of Public Law 102-575, 106 Stat. 4669); the 

Decree Quantifying the Federal Reserved Right for Black Canyon of the Gunnison National 

Park (Case No. 01CW05, District Court, Colorado Water Division No. 4, 2008); the Colorado 

River Drought Contingency Plan Authorization Act (Public Law 116-14); or the rules, criteria, 

guidelines, and decisions referenced within this AOP.

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42 2023 AOP – November 22, 2022

ACRONYMS AND ABBREVIATIONS

500 Plus Plan Memorandum of Understanding (MOU) to maintain the elevation 

in Lake Mead, signed December 15, 2021

1944 United StatesMexico Water TreatyUtilization of Waters of the Colorado and Tijuana Rivers and of 

the Rio Grande, the Treaty Between the United States of America 

and Mexico, signed February 3, 1944

AMWG Glen Canyon Dam Adaptive Management Work Group

AOP Annual Operating Plan

AWBA Arizona Water Banking Authority

Brock Warren H. Brock Reservoir

CAWCD Central Arizona Water Conservation District

CBRFC National Weather Service’s Colorado Basin River Forecast Center

CFR Code of Federal Regulations

cfs cubic feet per second

cms cubic meters per second

Consolidated Decree Consolidated Decree of the Supreme Court of the United States in 

Arizona v. California, 547 U.S. 150

CPM Colorado pikeminnow

CRBPA Colorado River Basin Project Act of 1968

DCP Drought Contingency Plan

DROA Drought Response Operations Agreement

DSS Developed Shortage Supply

FG-Ops Flaming Gorge Operation Plan

IBWC International Boundary and Water Commission

ICS Intentionally Created Surplus

ICUA Intentionally Created Unused Apportionment

IID Imperial Irrigation District

IOPP Inadvertent Overrun and Payback Policy

LB DCP Agreement Lower Basin Drought Contingency Plan Agreement

LTEMP Long-Term Experimental and Management Plan

LTSP Larval Trigger Study Plan

maf million acre-feet

mcm million cubic meters

MOU Memorandum of Understanding

MWD The Metropolitan Water District of Southern California

NIB Northerly International Boundary

Operating Criteria Criteria for Coordinated Long-Range Operation of Colorado River

Reservoirs Pursuant to the Colorado River Basin Project Act of 

September 30, 1968

ppm parts per million

PSCP Pilot System Conservation Program

Reclamation Bureau of Reclamation

ROD Record of Decision

SCPP System Conservation Pilot Program

Secretary Secretary of the U.S. Department of the Interior

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43 2023 AOP – November 22, 2022

SEIS Supplemental Environmental Impact Statement

SIB Southerly International Boundary

SIRA Storage and Interstate Release Agreement

SJRIP San Juan River Basin Recovery Implementation Program

SMB Smallmouth bass

SNWA Southern Nevada Water Authority

UCRC Upper Colorado River Commission

UCRIP Upper Colorado River Endangered Fish Recovery Program

USACE U.S. Army Corps of Engineers

USFWS U.S. Fish and Wildlife Service

WAPA Western Area Power Administration

WY Water Year

YDP Yuma Desalting Plant

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