Mohave Valley Conservation Area 2019 Annual Report
May 2021
Work conducted under LCR MSCP Work Task E35 Lower Colorado River Multi-Species Conservation Program Steering Committee Members
Federal Participant Group California Participant Group
Bureau of Reclamation California Department of Fish and Wildlife U.S. Fish and Wildlife Service City of Needles National Park Service Coachella Valley Water District Bureau of Land Management Colorado River Board of California Bureau of Indian Affairs Bard Water District Western Area Power Administration Imperial Irrigation District Los Angeles Department of Water and Power Palo Verde Irrigation District Arizona Participant Group San Diego County Water Authority Southern California Edison Company Arizona Department of Water Resources Southern California Public Power Authority Arizona Electric Power Cooperative, Inc. The Metropolitan Water District of Southern Arizona Game and Fish Department California Arizona Power Authority Central Arizona Water Conservation District Cibola Valley Irrigation and Drainage District Nevada Participant Group City of Bullhead City City of Lake Havasu City Colorado River Commission of Nevada City of Mesa Nevada Department of Wildlife City of Somerton Southern Nevada Water Authority City of Yuma Colorado River Commission Power Users Electrical District No. 3, Pinal County, Arizona Basic Water Company Golden Shores Water Conservation District Mohave County Water Authority Mohave Valley Irrigation and Drainage District Native American Participant Group Mohave Water Conservation District North Gila Valley Irrigation and Drainage District Hualapai Tribe Town of Fredonia Colorado River Indian Tribes Town of Thatcher Chemehuevi Indian Tribe Town of Wickenburg Salt River Project Agricultural Improvement and Power District Unit “B” Irrigation and Drainage District Conservation Participant Group Wellton-Mohawk Irrigation and Drainage District Yuma County Water Users’ Association Ducks Unlimited Yuma Irrigation District Lower Colorado River RC&D Area, Inc. Yuma Mesa Irrigation and Drainage District The Nature Conservancy
Other Interested Parties Participant Group
QuadState Local Governments Authority Desert Wildlife Unlimited
Lower Colorado River Multi-Species Conservation Program
Mohave Valley Conservation Area 2019 Annual Report
Prepared by: Laken Anderson, Restoration Group Laura Beth Sabin, Wildlife Group Jeff Lantow, Fisheries Group Becky Blasius and Jimmy Knowles, Adaptive Management Group
Lower Colorado River Multi-Species Conservation Program Bureau of Reclamation Lower Colorado Basin Boulder City, Nevada http://www.lcrmscp.gov May 2021
Anderson, L., L.B. Sabin, J. Lantow, B. Blasius, and J. Knowles. 2021. Mohave Valley Conservation Area, 2019 Annual Report. Lower Colorado River Multi-Species Conservation Program, Bureau of Reclamation, Boulder City, Nevada.
ACRONYMS AND ABBREVIATIONS
CSLC California State Lands Commission
FY fiscal year
LCR MSCP Lower Colorado River Multi-Species Conservation Program
MVCA Mohave Valley Conservation Area
PIT passive integrated transponder
Reclamation Bureau of Reclamation
Symbols
< less than
CONTENTS
Page
1.0 Introduction ...... 1 1.1 Background ...... 1 1.2 Previous Activities ...... 1 2.0 Conservation Area Information ...... 2 2.1 Purpose ...... 2 2.2 Location ...... 2 2.3 Landownership ...... 4 2.4 Water ...... 4 2.5 Agreements ...... 4 2.6 Public Use ...... 5 2.7 Law Enforcement ...... 5 2.8 Wildfire Management ...... 5 3.0 Habitat Development and Management...... 6 3.1 Planting ...... 6 3.2 Irrigation ...... 6 3.3 Site Management ...... 6 4.0 Monitoring ...... 8 4.1 Backwater Monitoring ...... 8 4.1.1 Native Fishes ...... 8 4.1.2 Water Quality ...... 9 4.2 Avian Monitoring...... 9 4.3 Small Mammal Monitoring...... 9 4.4 MacNeill’s Sootywing Skipper Monitoring...... 9 5.0 Habitat Creation Conservation Measure Accomplishment...... 9 5.1 Vegetation Monitoring ...... 9 5.2 Evaluation of Conservation Area Habitat ...... 10 6.0 Adaptive Management Recommendations ...... 10
Literature Cited ...... 11
Tables
Table Page
1 MVCA backwater scanning summary ...... 8
i Figures
Figure Page
1 Location of the MVCA within Reach 3...... 3 2 Managed acreage of the MVCA for FY19...... 7
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1.0 INTRODUCTION
The purpose of this annual report is to summarize all activities that have occurred at the Mohave Valley Conservation Area (MVCA) from October 1, 2018, through September 30, 2019, which is Federal fiscal year (FY) 2019, and projected activities for FY20. Use of Colorado River water is presented for the calendar year, January 1 through December 31, 2019, consistent with the Colorado River Accounting and Water Use Report: Arizona, California, and Nevada, Calendar Year 2019 (Bureau of Reclamation [Reclamation] 2020).
1.1 Background
The MVCA is a connected backwater created to divert water off the main stem of the Colorado River just below River Mile 237. Diverted flows run through an excavated channel, enter the existing Park Moabi backwater, and converge with the river 2 miles downstream from the new point of diversion. Excavating the channel created 561 acres of backwater habitat. The footprint of this conservation area is approximately 92 acres, with native land cover types lining the banks and upland slopes of the backwater accounting for the additional 31 acres.
The MVCA is located 13 miles south of Needles, California, along the Colorado River. The 149-acre property resides within the boundary of Park Moabi Regional Park. The land is owned by the California State Lands Commission (CSLC) and leased to San Bernardino County. Prior to approaching the CSLC and county about the backwater project, the 149-acre parcel was used as an off- highway vehicle recreational area; however, once the backwater project was presented, the county was willing to divide the property to accommodate both uses.
The project’s area of impact involved the entire 149 acres (includes areas of fill), as well as lands at the top and bottom of the parcel, to connect the backwater to the main stem of the Colorado River and the Park Moabi channel. Excavated material was used throughout the site to create the desired contour elevations, but the majority of the excavated material was used to create terrain within the county’s off-highway vehicle area.
1.2 Previous Activities
The CSLC (the landowner) and San Bernardino County (the lessee) were approached about the project in 2012. Basic, conceptual ideas about the project
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were presented to the CSLC and the county, and discussions and lease agreement negotiations continued, but they could not move toward a final agreement without an official design proposal for the project.
Reclamation worked with the CSLC to ensure National Environmental Policy Act/California Environmental Quality Act permitting requirements are met. Both the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service were notified about the project.
A survey of the 149-acre parcel was conducted to establish new control points and to develop elevation contours. Additionally, a temporary gauging station was installed directly across the river from the proposed inlet location so the river stage could be monitored. The data, in conjunction with the site elevation data, were used to determine the volume of material that would be excavated to achieve the desired depth of the backwater.
The permits necessary to perform a geotechnical survey were acquired, and a survey was conducted in June 2014.
Riparian bird surveys were conducted in existing habitat in April and May 2015. No LCR MSCP species were detected.
2.0 CONSERVATION AREA INFORMATION 2.1 Purpose
Backwater habitat maintained within the MVCA will be managed for flannelmouth suckers (Catostomus latipinnis), razorback suckers (Xyrauchen texanus), and bonytail (Gila elegans). The primary purposes of this site are fisheries habitat establishment and maintenance. The conservation area encompasses nearly 90 acres of Colorado River historic floodplain.
2.2 Location
The MVCA is located in Reach 3, within Moabi Regional Park, California, near Needles, California. It is within the historic floodplain of the lower Colorado River and adjacent to River Mile 237–238 on the California side (figure 1).
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Figure 1.—Location of the MVCA within Reach 3.
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2.3 Landownership
Moabi Regional Park 100 Park Moabi Rd Needles, CA 92363
The MVCA is located within Moabi Regional Park, California, which is owned by the CSLC, and leased to San Bernardino County. Pirate Cove, a concessionaire of the county, operates a resort within the park boundary. Reclamation entered into a lease agreement with the CSLC for a 149-acre parcel to establish the MVCA. The lease agreement between Reclamation and the CSLC was revised to remove the fill area from the lease agreement and to reflect the 90-acre conservation area boundary from the final as-built survey completed by Reclamation.
2.4 Water
Water for the MVCA is supplied through the LCR MSCP Water Accounting Agreement passed by Congress as part of the Omnibus Public Land Management Act of 2009 (Public Law No. 111-11, Title IX, Subtitle E, 123 Statute 991, 1327-29). The act permits Reclamation to create and manage conservation areas, which do not contain any water entitlement from the U.S. Secretary of the Interior, by using Colorado River water to meet the performance requirements of the LCR MSCP. Under the Water Accounting Agreement, Reclamation shall not consider any resulting increase in evaporation or percolation of lower Colorado River water to be a diversion or consumptive use.
The MVCA is 61 acres of connected backwater habitat that diverts water off the main stem of the lower Colorado River, just south of River Mile 237, and returns to the water mainstem 2 miles downstream.
2.5 Agreements
The lease agreement between Reclamation and the CSLC provides the terms of use for the MVCA property within the Park Moabi Regional Park boundary. The LCR MSCP submitted the application to the CSLC to modify an existing lease currently held by San Bernardino County. The lease modification granted the LCR MSCP the authority to develop the MVCA within the designated project area.
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2.6 Public Use
Low-impact public uses, such as wildlife watching, sport fishing, non-motorized outdoor recreation activities, and educational outreach, are authorized at the MVCA.
2.7 Law Enforcement
Reclamation continues to work with local officials to ensure law enforcement activities do not conflict with the LCR MSCP Habitat Conservation Plan. Law enforcement activities at the MVCA are performed primarily by the Bureau of Land Management law enforcement officer under the LCR MSCP’s site-specific Fire Management & Law Enforcement Strategy (LCR MSCP 2010). Additional local law enforcement assistance is available through the San Bernardino County Sheriff’s Department.
2.8 Wildfire Management
The LCR MSCP is responsible for wildfire management at the MVCA. As guided by commitments in the LCR MSCP Habitat Conservation Plan, wildfire management practices on the conservation area will “…reduce the risk of loss of related habitat to wildfire by providing resources to suppress wildfires, e.g., contributing to and integrating with local, State, and Federal agency fire management plans, and implement land management and habitat creation measures to support the reestablishment of native vegetation that is lost to wildfire” (LCR MSCP 2010).
Federal, State, and local fire agencies, either by existing management agreements or mutual aid agreements, provide wildland fire suppression, incident dispatch, fire investigation, fuels reduction, and potential fire restrictions. The full range of suppression strategies are available to managers provided that selected options do not compromise firefighter or public safety, are cost effective, consider the benefits of suppression and the values to be protected, and are consistent with resource objectives.
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3.0 HABITAT DEVELOPMENT AND MANAGEMENT 3.1 Planting
There were no new plantings at the MVCA during FY19. The backwater is maintained by the daily rise and fall of the Colorado River’s operation.
3.2 Irrigation
No irrigation was conducted at the MVCA during FY19, as all honey mesquite (Prosopis glandulosa) and marsh plantings utilize groundwater and river stage.
3.3 Site Management
In May 2019, construction was completed on the conservation area, and the MVCA was open to the public. In total, 1.475 million cubic yards of material was moved, including 1.15 million cubic yards using land-based equipment and 325,000 cubic yards by dredging. The backwater is 15 feet deep at the average high river stage of 457, and measures 61 acres, including marsh and open water (figure 2). The removal of the southern outlet cofferdam took place in January 2019, opening the connection to the Park Moabi channel. The northern inlet connection was deepened in January, when the river stage was low and access easier. The dredge was disassembled using a crane and hauled offsite to the next job in May. The northern inlet bridge stoplogs were installed in August 2019 to manage the water levels within the MVCA. Three public information kiosk signs were designed and installed in September.
During times of low river stage, specifically during the fall and winter months, Off-highway vehicles are ignoring posted “Keep Out” signage and are negatively impacting the growth of marsh plants that were planted in FY18. To protect the eastern portion of the conservation area, 5,200 feet of post and cable fence could be installed from the northern inlet bridge down to the southern outlet bridge.
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Figure 2.—Managed acreage of the MVCA for FY19.
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4.0 MONITORING 4.1 Backwater Monitoring
Backwater construction was completed midway through 2019, and this limited monitoring activities at the site. Monitoring activities consisted of remote passive integrated transponder (PIT) tag scanning from the permanent antennas that were installed in the water control structures at the inflow and outflow of the backwater.
4.1.1 Native Fishes The permanent remote PIT tag scanner at the inflow to the backwater functioned continuously throughout FY19, and the one at the outflow functioned continuously beginning January 31, 2019. All PIT tag data were summarized by fiscal year quarters (table 1).
Table 1.—MVCA backwater scanning summary
Razorback Flannelmouth Total uniques Bonytail suckers suckers Quarter 1 139 0 139 0
Quarter 2 201 0 201 0
Quarter 3 327 0 327 0
Inflow Quarter 4 317 0 317 0
Total 984 0 984 0
FY19 uniques 660 0 660 0
Quarter 1* 0 0 0 0
Quarter 2 910 0 910 0
Quarter 3 1,187 1 1,186 0
Quarter 4 710 0 710 0 Outflow Total 2,807 1 2,806 0
FY19 uniques 1,665 1 1,664 0
FY19 uniques combined 1,932 1** 1,931 0 * A cofferdam was separating Park Moabi and the MVCA until January 31, 2019. ** A bonytail was released October 19, 2016, in Park Moabi at 275 millimeters. It was detected twice on the scanner, 12 minutes apart, on April 12, 2019.
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The two scanners combined contacted 1,932 unique PIT tags, 1,931 razorback suckers and 1 bonytail. The bonytail was a fish released in October 2016 in Park Moabi. This fish was released at 275 millimeters as part of a cohort of fish < 300 millimeters; the LCR MSCP did not seek credit for this cohort.
The cofferdam separating the outflow of the MVCA backwater and Park Moabi was removed on January 31, 2019. The removal of this dam allowed fish in Park Moabi to access the outflow scanner of the backwater. Park Moabi is a routine stocking location for the fish augmentation program, and many of these fishes are subsequently detected on the outflow scanner.
4.1.2 Water Quality No water quality monitoring was conducted due to ongoing construction activities.
4.2 Avian Monitoring
No avian monitoring occurred in FY19.
4.3 Small Mammal Monitoring
No small mammal monitoring occurred in FY19.
4.4 MacNeill’s Sootywing Skipper Monitoring
No MacNeill’s Sootywing Skipper (Pholisora gracielae = Hesperopsis gracielae [MacNeill]) monitoring occurred in FY19.
5.0 HABITAT CREATION CONSERVATION MEASURE ACCOMPLISHMENT 5.1 Vegetation Monitoring
Vegetation data were collected in FY19 using lidar. Lidar measures the vegetation structure throughout the canopy and provides the ability to identify structural diversity and successional growth stages. Conservation area vegetation
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will be evaluated on a periodic basis using lidar to ensure the habitat is meeting species’ requirements. A procedure to analyze and provide vegetation structure metrics will be developed, and results will be presented in future reports.
5.2 Evaluation of Conservation Area Habitat
The Final Habitat Creation Conservation Measure Accomplishment Tracking Process was finalized in October 2011 (LCR MSCP 2011). All areas within the MVCA were designed to benefit covered species at the landscape level.
To meet species habitat creation requirements, the Habitat Conservation Plan provides goals for habitat creation based on land cover types. These land cover types are described using the Anderson and Ohmart vegetation classification system (Anderson et al. 1976, 1984a, 1984b). In FY19, there were no species with creditable acres at the MVCA.
6.0 ADAPTIVE MANAGEMENT RECOMMENDATIONS
Adaptive management relies on the initial receipt of new information, the analysis of that information, and the incorporation of the new information into the design and/or direction of future project work (LCR MSCP 2007). Under the Adaptive Management Program, habitat creation sites will be assessed for biological effectiveness and whether they fulfill the conservation measures outlined in the Habitat Conservation Plan for 271 covered species and to determine if they potentially benefit 5 evaluation species. Post-development monitoring and species research results will be used to adaptively manage habitat creation sites after initial implementation. Once monitoring data are collected over a few years, and then analyzed for the MVCA, recommendations may be made through the adaptive management process for site improvements in the future.
There are no adaptive management recommendations for the MVCA at this time.
1 The northern Mexican gartersnake (Thamnophis eques megalops) was added as a covered species by an amendment to the Program Documents on March 5, 2018.
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LITERATURE CITED
Anderson, B.W. and R.D. Ohmart. 1976. Vegetation Type Maps of the Lower Colorado River from Davis Dam to the Southerly International Boundary, Final Report. Submitted to the Bureau of Reclamation, Boulder City, Nevada.
_____. 1984a. Vegetation Management Study for the Enhancement of Wildlife Along the Lower Colorado River, Final Report. Submitted to the Bureau of Reclamation, Boulder City, Nevada.
_____. 1984b. Lower Colorado River Riparian Methods of Quantifying Vegetation Communities to Prepare Type Maps, Final Report. Submitted to the Bureau of Reclamation, Boulder City, Nevada.
Bureau of Reclamation. 2020. Colorado River Accounting and Water Use Report: Arizona, California, and Nevada, Calendar Year 2019. Bureau of Reclamation, Boulder City, Nevada.
LCR MSCP (see Lower Colorado River Multi-Species Conservation Program).
Lower Colorado River Multi-Species Conservation Program (LCR MSCP). 2007. Final Science Strategy. Bureau of Reclamation, Boulder City, Nevada.
_____. 2010. Lower Colorado River Multi-Species Conservation Program Fire Management & Law Enforcement Strategy. Bureau of Reclamation, Boulder City, Nevada.
_____. 2011. Final Habitat Creation Conservation Measure Accomplishment Tracking Process. Bureau of Reclamation, Boulder City, Nevada. October 26.
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