GCMRC modeling used in decision-making process for new Glen Canyon Dam Environmental Impact Statements
USGS Southwest Biological Science Center's Grand Canyon Monitoring and Research Center prepared a cooperator publication and a presentation that report on modeling results to evaluate potential effects of reservoir management on various resources in Lake Powell and Grand Canyon.
The Report
The Bureau of Reclamation (Reclamation) requested USGS scientific support to provide models that predict the effects to the Colorado River ecosystem, including threatened and endangered species downstream of Glen Canyon Dam in Grand Canyon, for use in a Biological Assessment.
The modeling results were published in a SBSC's Grand Canyon Monitoring and Research Center cooperator report, "Modeling the Impacts of Glen Canyon Dam Operations on Colorado River Resources."
Reclamation used the results in their decision-making to produce a supplemental and new Environmental Impact Statement (EIS) as part of a National Environmental Policy Act (NEPA) analysis that assesses the effects of changing water flows from Glen Canyon Dam on the downstream ecosystem.
The first sEIS (Interim Guidelines sEIS) modifies Reclamation’s 2007 Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead that determines annual water releases from Glen Canyon Dam based on inflow to Lake Powell, the power generating requirements of Glen Canyon Dam, and relative lake levels of Lake Powell and Lake Mead.
Drought conditions have lowered the level of Lake Powell and may require Glen Canyon Dam to release less water than was analyzed in the Interim EIS (7-million-acre feet/year).
More information about the Glen Canyon Adaptive Management Program can be accessed at: https://www.usbr.gov/uc/progact/amp/index.html
The Presentation
The presentation was shared at a public Glen Canyon Adaptive Management Group Meeting on January 31, 2024, to support preparation of the upcoming Draft Long-term Experimental and Management Plan (LTEMP) Supplemental Environmental Impact Statement (SEIS).
To access the presentation, click the link below:
Citations:
Yackulic, C.B., Bair, L.S., Eppehimer, D.E., Salter, G.L., Deemer, B.R., Butterfield, B.J., Kasprak, A., Caster, J.J., Fairley, H.C., Grams, P.E., Mihalevich, B., Palmquist, E.C., and Sankey, J.B., 2024, Modeling the impacts of Glen Canyon Dam operations on Colorado River resources: Phoenix, Ariz., U.S. Department of Interior, Bureau of Reclamation, cooperator publication prepared by U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, Ariz., April 2024, 133 p., https://www.usbr.gov/uc/progact/amp/pdfs/LTEMP/20240408-ModelingImpactsGlenCanyonDamOperationsColoradoRiverResources-508-UCRO.pdf
Yackulic, C.B., Bair, L.S., Eppehimer, D.E., Salter, G.L., Butterfield, B.J., Caster, J.J., Deemer, B.R., Fairley, H., Grams, P.E., Kasprak, A., Palmquist, E.C., and Sankey, J.B., 2024, Modeling the impacts of Glen Canyon Dam operations on Colorado River resources [presentation], LTEMP SEIS meeting (virtual), January 31, 2024: Flagstaff, Ariz., US Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, https://www.usgs.gov/centers/southwest-biological-science-center/science/modeling-impacts-glen-canyon-dam-operations
Smallmouth bass expansion downstream of Glen Canyon Dam
Grand Canyon Monitoring and Research Projects
USGS Southwest Biological Science Center's Grand Canyon Monitoring and Research Center prepared a cooperator publication and a presentation that report on modeling results to evaluate potential effects of reservoir management on various resources in Lake Powell and Grand Canyon.
The Report
The Bureau of Reclamation (Reclamation) requested USGS scientific support to provide models that predict the effects to the Colorado River ecosystem, including threatened and endangered species downstream of Glen Canyon Dam in Grand Canyon, for use in a Biological Assessment.
The modeling results were published in a SBSC's Grand Canyon Monitoring and Research Center cooperator report, "Modeling the Impacts of Glen Canyon Dam Operations on Colorado River Resources."
Reclamation used the results in their decision-making to produce a supplemental and new Environmental Impact Statement (EIS) as part of a National Environmental Policy Act (NEPA) analysis that assesses the effects of changing water flows from Glen Canyon Dam on the downstream ecosystem.
The first sEIS (Interim Guidelines sEIS) modifies Reclamation’s 2007 Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead that determines annual water releases from Glen Canyon Dam based on inflow to Lake Powell, the power generating requirements of Glen Canyon Dam, and relative lake levels of Lake Powell and Lake Mead.
Drought conditions have lowered the level of Lake Powell and may require Glen Canyon Dam to release less water than was analyzed in the Interim EIS (7-million-acre feet/year).
More information about the Glen Canyon Adaptive Management Program can be accessed at: https://www.usbr.gov/uc/progact/amp/index.html
The Presentation
The presentation was shared at a public Glen Canyon Adaptive Management Group Meeting on January 31, 2024, to support preparation of the upcoming Draft Long-term Experimental and Management Plan (LTEMP) Supplemental Environmental Impact Statement (SEIS).
To access the presentation, click the link below:
Citations:
Yackulic, C.B., Bair, L.S., Eppehimer, D.E., Salter, G.L., Deemer, B.R., Butterfield, B.J., Kasprak, A., Caster, J.J., Fairley, H.C., Grams, P.E., Mihalevich, B., Palmquist, E.C., and Sankey, J.B., 2024, Modeling the impacts of Glen Canyon Dam operations on Colorado River resources: Phoenix, Ariz., U.S. Department of Interior, Bureau of Reclamation, cooperator publication prepared by U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, Ariz., April 2024, 133 p., https://www.usbr.gov/uc/progact/amp/pdfs/LTEMP/20240408-ModelingImpactsGlenCanyonDamOperationsColoradoRiverResources-508-UCRO.pdf
Yackulic, C.B., Bair, L.S., Eppehimer, D.E., Salter, G.L., Butterfield, B.J., Caster, J.J., Deemer, B.R., Fairley, H., Grams, P.E., Kasprak, A., Palmquist, E.C., and Sankey, J.B., 2024, Modeling the impacts of Glen Canyon Dam operations on Colorado River resources [presentation], LTEMP SEIS meeting (virtual), January 31, 2024: Flagstaff, Ariz., US Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, https://www.usgs.gov/centers/southwest-biological-science-center/science/modeling-impacts-glen-canyon-dam-operations