The All-American Canal (AAC) in southern Imperial County, California, has historically been unlined, resulting in substantial losses to seepage. In 2006, the Imperial Irrigation District, under a contract with the United States Bureau of Reclamation, initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC.
Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project
Active
By California Water Science Center
February 23, 2022
The USGS seeks to increase understanding of the groundwater system in the vicinity of the Lower Colorado Water Supply Project well field and to estimate future groundwater levels and total dissolved solids concentrations in the wells and the long-term viability of the Lower Colorado Water Supply Project.
Sources/Usage: Public Domain. View Media Details
There is concern about the long-term viability of the Lower Colorado Water Supply Project (LCWSP), a well field in the Imperial Sand Dunes Recreational Area, which began withdrawing water in 1991, regarding both the declining groundwater levels and potential increase in water drawn by the wells. The continued decline in East Mesa water-level elevations, since the construction of a parallel, lined All-American Canal (AAC) in the late 2000’s, necessitated that the first two LCWSP wells be re-drilled or retrofitted to maintain functionality. There is uncertainty about the quality of future water withdrawn by the LCWSP to meet the acceptable total dissolved solids (TDS) concentrations limit for discharge into the AAC.​
The overall objectives of the study are to improve the understanding of the groundwater system in the vicinity of the LCWSP well field, and to estimate the impact of lining the AAC on groundwater levels and TDS concentrations in LCWSP wells up to the year 2070. The study consists of the following ongoing work:
- Initial characterization of the groundwater system and establishment of a monitoring network;
- Evaluation of the groundwater system and its relation to the water quality produced from the LCWSP wells, and;
- Development and application of a numerical model to provide forecasts of water levels and TDS concentrations in water pumped from LCWSP wells.
Project Benefits | Monitoring Network | Groundwater System Characterization | Groundwater Modeling | Background | References
Project Benefits
Water Resources in the East Mesa
This study is relevant to stakeholders and the general public by providing the information needed regarding the amount and quality of water in all components of the water cycle, advancing the understanding of processes that determine water availability, predicting changes in the quantity and quality of water resources in response to future management scenarios, and through an understanding of the conditions leading to water shortages to better manage the water resources of the region.
Transboundary Benefits
As the study area spans the United States-Mexico border region, project data and analysis will support the Transboundary Aquifer Assessment Program objectives to “improve the knowledge base of transboundary aquifers between the United States and Mexico” (IBWC, 2009). Regional models created for this study can be used by both countries to understand and manage transboundary aquifer resources using a common, science-based approach for evaluating groundwater in the Imperial and Mexicali Valley.
Lower Colorado Monitoring Network
Established by USGS between 2009 to 2011 (Coes and others, 2015), the monitoring network associated with the LCWSP is a series of groundwater-level and water-quality wells, as well as streamgages and micro-gravity stations. Data collected from the monitoring network are used to inform all aspects of the ongoing research. An interactive map displays the sites and provides links to the most current data.
Initial Groundwater System Characterization
Sources/Usage: Public Domain. View Media Details
The initial characterization of the groundwater system included the following tasks:
- Collection of water-level data – depth to water is measured annually at 30 wells, and continuously at up to 10 wells, to determine changes to the regional water table;
- Collection of water-quality data – water from wells is sampled at 8 wells annually from a group of up to 24 wells, for physical properties, inorganic constituents, and isotopic tracers to evaluate sources of groundwater recharge and flow paths in the groundwater system;
- Collection of micro-gravity data – microgravity data will be measured annually at 33 stations to determine aquifer storage change, as well as a high-precision elevation survey of the land surface to assess whether subsidence has occurred.
A USGS Scientific Investigations Report summarizing work completed for the hydrologic monitoring network, Initial characterization of the groundwater system near the Lower Colorado Water Supply Project, Imperial Valley, California, is available for download at: https://doi.org/10.3133/sir20155102
Ongoing Groundwater Analysis and Investigation
The groundwater modeling portion of this study aims to develop and apply a tool to estimate future TDS concentrations in groundwater pumped from LCWSP wells up to the year 2075. While the operation of the LCWSP hydrologic monitoring network is active, the ongoing work consists of four project tasks to be completed from 2022 to 2026:
Data collection, compilation, and management (2022-2023)
-
Drilling and installation of deep, multiple-well monitoring sites
-
Drilling and installation of shallow observation wells to estimate seepage
-
Collection of nuclear magnetic resonance (NMR) data at two existing wells
Analysis (2022-2024)
-
Hydrologic Data Collection and Analysis
-
Groundwater Geochemistry
-
Hydrologic Framework Model
Groundwater Flow and Transport Model (2023-2024)
-
Refining the conceptual model to support numerical model development
-
Constructing and calibrating a numerical groundwater flow and solute transport model
Reports and Communications (2023-2026)
-
Project website
-
Data releases
-
Reports for analysis and modeling
Background
The All-American Canal has historically been unlined, which has been associated with substantial losses to seepage. In 2006, the Imperial Irrigation District (IID), under a contract with the United States Bureau of Reclamation (Reclamation), initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC. Construction was completed in 2010 and was estimated to conserve about 67,000 acre-feet per year of seepage (U.S. Bureau of Reclamation, 1994).
Reclamation operates the LCWSP to replace surface water that was diverted from the Colorado River for users in California that do not hold, or hold insufficient, Colorado River rights. Water pumped from the LCWSP is discharged into the AAC. The desired quality of water for acceptable discharge into the AAC is 879 ± 30 milligrams per liter or less of TDS concentrations on an average annual flow-weighted basis (U.S. Bureau of Reclamation, 2004).
The use of the lined AAC has greatly reduced groundwater recharge from seepage. TDS concentrations in water from LCWSP wells likely will increase as the low-TDS component of groundwater associated with AAC seepage since 1940 declines and native, high-TDS groundwater becomes the dominant source.
References
Coes, A.L., Land, M., Densmore, J.N., Landrum, M., Beisner, K., Kennedy, J.R., Macy, J.P., Tillman, F., 2015. Initial Characterization of the Groundwater System near the Lower Colorado Water Supply Project, Imperial Valley, California. U.S. Geological Survey, Scientific Investigations Report 2015–5102, p 72.
IBWC, 2009. Joint Report of the Principal Engineers Regarding Joint Cooperative Process. United States-Mexico for the Transboundary Aquifer Assessment Program. 2009. Accessed online 30 December 2021. wrrc.arizona.edu/sites/wrrc.arizona.edu/files/images/Joint-Report-TAAP-8-19-09.pdf (accessed on 25 December 2020).
U.S. Bureau of Reclamation, 1994, Final environmental impact statement/final environmental impact report—AllAmerican Canal Lining Project: U. S. Department of the Interior, Bureau of Reclamation, Lower Colorado River Region, Imperial Irrigation District, 176 p.
U.S. Bureau of Reclamation, 2004, Quality of project well field water to be exchanged, Amendment 1 to Contract among the United States, Imperial Irrigation District, and Coachella Valley Water District for exchange of water from the Lower Colorado Water Supply Project Well Field for Colorado River Water: U.S. Department of the Interior, Bureau of Reclamation, no. 2–07–30–W0277, dated April 26, 2004, 2 p.
Below are multimedia items associated with this project.
All-American Canal
The All-American Canal (AAC) in southern Imperial County, California, has historically been unlined, resulting in substantial losses to seepage. In 2006, the Imperial Irrigation District, under a contract with the United States Bureau of Reclamation, initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC.
Imperial Sand Dunes Recreation Area
The Imperial Sand Dunes Recreational Area, located in Imperial County in the far southeast corner of California. It is home to a groundwater well field that is part of the U.S. Bureau of Reclamation's Lower Colorado Water Supply Project.
The Imperial Sand Dunes Recreational Area, located in Imperial County in the far southeast corner of California. It is home to a groundwater well field that is part of the U.S. Bureau of Reclamation's Lower Colorado Water Supply Project.
Water Quality Sampling, Imperial Sand Dunes, California
A USGS Hydrologist purges a groundwater monitoring well in preparation for water-quality sampling in the Imperial Sand Dunes Recreation area, Imperial Valley, California. This sampling was done as part of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
A USGS Hydrologist purges a groundwater monitoring well in preparation for water-quality sampling in the Imperial Sand Dunes Recreation area, Imperial Valley, California. This sampling was done as part of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
Checking the Hydraulic Connections between a Well and Aquifer
A USGS Hydrologist re-develops a monitoring well to ensure a good hydraulic connection is present between the perforations in the well and surrounding aquifer. This work was being done as part of a groundwater system characterization and groundwater quality study being conducted along the All-American Canal that runs through the area.
A USGS Hydrologist re-develops a monitoring well to ensure a good hydraulic connection is present between the perforations in the well and surrounding aquifer. This work was being done as part of a groundwater system characterization and groundwater quality study being conducted along the All-American Canal that runs through the area.
Water-Quality Sample Collection
A USGS Hydrologist collects water-quality samples as part of a wellbore characterization test at site LCWSP2 of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
A USGS Hydrologist collects water-quality samples as part of a wellbore characterization test at site LCWSP2 of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
Groundwater Monitoring, Imperial County, California
Recording location and water-level data at a groundwater monitoring site in the Imperial Sand Dunes Recreation area, Imperial County, California. The work is being done as part of a water quality and groundwater system characterization study along the All-American Canal that runs through the area.
Recording location and water-level data at a groundwater monitoring site in the Imperial Sand Dunes Recreation area, Imperial County, California. The work is being done as part of a water quality and groundwater system characterization study along the All-American Canal that runs through the area.
The USGS seeks to increase understanding of the groundwater system in the vicinity of the Lower Colorado Water Supply Project well field and to estimate future groundwater levels and total dissolved solids concentrations in the wells and the long-term viability of the Lower Colorado Water Supply Project.
Sources/Usage: Public Domain. View Media Details
There is concern about the long-term viability of the Lower Colorado Water Supply Project (LCWSP), a well field in the Imperial Sand Dunes Recreational Area, which began withdrawing water in 1991, regarding both the declining groundwater levels and potential increase in water drawn by the wells. The continued decline in East Mesa water-level elevations, since the construction of a parallel, lined All-American Canal (AAC) in the late 2000’s, necessitated that the first two LCWSP wells be re-drilled or retrofitted to maintain functionality. There is uncertainty about the quality of future water withdrawn by the LCWSP to meet the acceptable total dissolved solids (TDS) concentrations limit for discharge into the AAC.​
The overall objectives of the study are to improve the understanding of the groundwater system in the vicinity of the LCWSP well field, and to estimate the impact of lining the AAC on groundwater levels and TDS concentrations in LCWSP wells up to the year 2070. The study consists of the following ongoing work:
- Initial characterization of the groundwater system and establishment of a monitoring network;
- Evaluation of the groundwater system and its relation to the water quality produced from the LCWSP wells, and;
- Development and application of a numerical model to provide forecasts of water levels and TDS concentrations in water pumped from LCWSP wells.
Project Benefits | Monitoring Network | Groundwater System Characterization | Groundwater Modeling | Background | References
Project Benefits
Water Resources in the East Mesa
This study is relevant to stakeholders and the general public by providing the information needed regarding the amount and quality of water in all components of the water cycle, advancing the understanding of processes that determine water availability, predicting changes in the quantity and quality of water resources in response to future management scenarios, and through an understanding of the conditions leading to water shortages to better manage the water resources of the region.
Transboundary Benefits
As the study area spans the United States-Mexico border region, project data and analysis will support the Transboundary Aquifer Assessment Program objectives to “improve the knowledge base of transboundary aquifers between the United States and Mexico” (IBWC, 2009). Regional models created for this study can be used by both countries to understand and manage transboundary aquifer resources using a common, science-based approach for evaluating groundwater in the Imperial and Mexicali Valley.
Lower Colorado Monitoring Network
Established by USGS between 2009 to 2011 (Coes and others, 2015), the monitoring network associated with the LCWSP is a series of groundwater-level and water-quality wells, as well as streamgages and micro-gravity stations. Data collected from the monitoring network are used to inform all aspects of the ongoing research. An interactive map displays the sites and provides links to the most current data.
Initial Groundwater System Characterization
Sources/Usage: Public Domain. View Media Details
The initial characterization of the groundwater system included the following tasks:
- Collection of water-level data – depth to water is measured annually at 30 wells, and continuously at up to 10 wells, to determine changes to the regional water table;
- Collection of water-quality data – water from wells is sampled at 8 wells annually from a group of up to 24 wells, for physical properties, inorganic constituents, and isotopic tracers to evaluate sources of groundwater recharge and flow paths in the groundwater system;
- Collection of micro-gravity data – microgravity data will be measured annually at 33 stations to determine aquifer storage change, as well as a high-precision elevation survey of the land surface to assess whether subsidence has occurred.
A USGS Scientific Investigations Report summarizing work completed for the hydrologic monitoring network, Initial characterization of the groundwater system near the Lower Colorado Water Supply Project, Imperial Valley, California, is available for download at: https://doi.org/10.3133/sir20155102
Ongoing Groundwater Analysis and Investigation
The groundwater modeling portion of this study aims to develop and apply a tool to estimate future TDS concentrations in groundwater pumped from LCWSP wells up to the year 2075. While the operation of the LCWSP hydrologic monitoring network is active, the ongoing work consists of four project tasks to be completed from 2022 to 2026:
Data collection, compilation, and management (2022-2023)
-
Drilling and installation of deep, multiple-well monitoring sites
-
Drilling and installation of shallow observation wells to estimate seepage
-
Collection of nuclear magnetic resonance (NMR) data at two existing wells
Analysis (2022-2024)
-
Hydrologic Data Collection and Analysis
-
Groundwater Geochemistry
-
Hydrologic Framework Model
Groundwater Flow and Transport Model (2023-2024)
-
Refining the conceptual model to support numerical model development
-
Constructing and calibrating a numerical groundwater flow and solute transport model
Reports and Communications (2023-2026)
-
Project website
-
Data releases
-
Reports for analysis and modeling
Background
The All-American Canal has historically been unlined, which has been associated with substantial losses to seepage. In 2006, the Imperial Irrigation District (IID), under a contract with the United States Bureau of Reclamation (Reclamation), initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC. Construction was completed in 2010 and was estimated to conserve about 67,000 acre-feet per year of seepage (U.S. Bureau of Reclamation, 1994).
Reclamation operates the LCWSP to replace surface water that was diverted from the Colorado River for users in California that do not hold, or hold insufficient, Colorado River rights. Water pumped from the LCWSP is discharged into the AAC. The desired quality of water for acceptable discharge into the AAC is 879 ± 30 milligrams per liter or less of TDS concentrations on an average annual flow-weighted basis (U.S. Bureau of Reclamation, 2004).
The use of the lined AAC has greatly reduced groundwater recharge from seepage. TDS concentrations in water from LCWSP wells likely will increase as the low-TDS component of groundwater associated with AAC seepage since 1940 declines and native, high-TDS groundwater becomes the dominant source.
References
Coes, A.L., Land, M., Densmore, J.N., Landrum, M., Beisner, K., Kennedy, J.R., Macy, J.P., Tillman, F., 2015. Initial Characterization of the Groundwater System near the Lower Colorado Water Supply Project, Imperial Valley, California. U.S. Geological Survey, Scientific Investigations Report 2015–5102, p 72.
IBWC, 2009. Joint Report of the Principal Engineers Regarding Joint Cooperative Process. United States-Mexico for the Transboundary Aquifer Assessment Program. 2009. Accessed online 30 December 2021. wrrc.arizona.edu/sites/wrrc.arizona.edu/files/images/Joint-Report-TAAP-8-19-09.pdf (accessed on 25 December 2020).
U.S. Bureau of Reclamation, 1994, Final environmental impact statement/final environmental impact report—AllAmerican Canal Lining Project: U. S. Department of the Interior, Bureau of Reclamation, Lower Colorado River Region, Imperial Irrigation District, 176 p.
U.S. Bureau of Reclamation, 2004, Quality of project well field water to be exchanged, Amendment 1 to Contract among the United States, Imperial Irrigation District, and Coachella Valley Water District for exchange of water from the Lower Colorado Water Supply Project Well Field for Colorado River Water: U.S. Department of the Interior, Bureau of Reclamation, no. 2–07–30–W0277, dated April 26, 2004, 2 p.
Below are multimedia items associated with this project.
All-American Canal
The All-American Canal (AAC) in southern Imperial County, California, has historically been unlined, resulting in substantial losses to seepage. In 2006, the Imperial Irrigation District, under a contract with the United States Bureau of Reclamation, initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC.
The All-American Canal (AAC) in southern Imperial County, California, has historically been unlined, resulting in substantial losses to seepage. In 2006, the Imperial Irrigation District, under a contract with the United States Bureau of Reclamation, initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC.
Imperial Sand Dunes Recreation Area
The Imperial Sand Dunes Recreational Area, located in Imperial County in the far southeast corner of California. It is home to a groundwater well field that is part of the U.S. Bureau of Reclamation's Lower Colorado Water Supply Project.
The Imperial Sand Dunes Recreational Area, located in Imperial County in the far southeast corner of California. It is home to a groundwater well field that is part of the U.S. Bureau of Reclamation's Lower Colorado Water Supply Project.
Water Quality Sampling, Imperial Sand Dunes, California
A USGS Hydrologist purges a groundwater monitoring well in preparation for water-quality sampling in the Imperial Sand Dunes Recreation area, Imperial Valley, California. This sampling was done as part of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
A USGS Hydrologist purges a groundwater monitoring well in preparation for water-quality sampling in the Imperial Sand Dunes Recreation area, Imperial Valley, California. This sampling was done as part of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
Checking the Hydraulic Connections between a Well and Aquifer
A USGS Hydrologist re-develops a monitoring well to ensure a good hydraulic connection is present between the perforations in the well and surrounding aquifer. This work was being done as part of a groundwater system characterization and groundwater quality study being conducted along the All-American Canal that runs through the area.
A USGS Hydrologist re-develops a monitoring well to ensure a good hydraulic connection is present between the perforations in the well and surrounding aquifer. This work was being done as part of a groundwater system characterization and groundwater quality study being conducted along the All-American Canal that runs through the area.
Water-Quality Sample Collection
A USGS Hydrologist collects water-quality samples as part of a wellbore characterization test at site LCWSP2 of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
A USGS Hydrologist collects water-quality samples as part of a wellbore characterization test at site LCWSP2 of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.
Groundwater Monitoring, Imperial County, California
Recording location and water-level data at a groundwater monitoring site in the Imperial Sand Dunes Recreation area, Imperial County, California. The work is being done as part of a water quality and groundwater system characterization study along the All-American Canal that runs through the area.
Recording location and water-level data at a groundwater monitoring site in the Imperial Sand Dunes Recreation area, Imperial County, California. The work is being done as part of a water quality and groundwater system characterization study along the All-American Canal that runs through the area.