Hydrology

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Upper Colorado River Basin Hydrology Upper Colorado River Basin regularly experiences significant year to year hydrologic variability. During the 21-year period 2000 to 2020, however, the unregulated inflow to Lake Powell, which is a good measure of hydrologic conditions in the Colorado River Basin, was above average in only 4 out of the past 19 years. The period 2000-2020 is the lowest 21-year period since the closure of Glen Canyon Dam in 1963, with an average unregulated inflow of 8.62 maf, or 80 percent of the 30-year average (1981-2010). (For comparison, the 1981-2010 total water year average is 10.83 maf.) The unregulated inflow during the 2000-2020 period has ranged from a low of 2.64 maf (24 percent of average) in water year 2002 to a high of 15.97 maf (147 percent of average) in water year 2011. In water year 2018 unregulated inflow volume to Lake Powell was 4.6 maf (43 percent of average), the third driest year on record above 2002 and 1977. [1]

Current Status	Current Operations	Inflow Forecasts and Model Projections

Updates Upper Colorado Region Homepage Lake Powell Snow Chart Lake Powell Inflow Forecast Lake Powell Elevation Projections Lake Powell Release Projections Glen Canyon Dam Operations USBR Weekly Water Reports Upper Colorado Region Weekly Hydrology Summary Reservoir inflows (forecast and observed) Reservoir releases SNOTEL Lower Colorado Water Supply Report Water use Lower Colorado River Water Accounting Colorado River Basin Tea-Cup Diagrams USBR Monthly/Annual Reports 24-Month Study Monthly Summaries Annual Operating Plans for Colorado River reservoirs Snow Pack Reports Upper Colorado River Basin Snow Water Tracking Upper Colorado Basin Conditions Map Bureau of Reclamation- Snow Pack Report SNOWTEL Report The snowtel report is a calculating report, and takes approximately 3 minutes to run. Select the report under "Public", listed as "Colorado River above Lake Powell" (116 snowtel sites). Data source is updated at least daily. U.S. Drought Monitor U.S. Drought Monitor Tree Flow Data Inflow Volumes to Lake Powell and Release Volumes from Glen Canyon Dam https://usea.org/sites/default/files/event-/Final_Colorado_Overview.pdf http://www.lakepowell.org/page_two/what_s_new/what_s_new.html https://www.hcn.org/blogs/goat/is-lake-powell-really-shrinking Water Year Unregulated Inflow (maf) Release Volume (maf) 2021 (Nov forecast) 06.791 08.234 2020 05.847 08.230 2019 12.951 09.001 2018 04.612 09.000 2017 11.905 09.000 2016 09.616 09.000 2015 10.174 09.000 2014 10.381 07.480 2013 05.117 08.232 2012 04.908 09.466 2011 15.971 12.518 2010 08.426 08.235 2009 10.220 08.236 2008 12.086 08.978 2007 08.754 08.231 2006 08.626 08.228 2005 12.795 08.232 2004 05.913 08.231 2003 06.161 08.229 2002 02.643 08.230 2001 06.994 08.236 2000 06.936 09.381 1999 12.800 11.204 1998 13.520 13.510 1997 17.053 13.824 1996 10.402 11.522 1995 15.905 09.223 1994 06.794 08.289 1993 14.437 08.102 1992 07.352 08.002 1991 08.801 08.121 1990 05.311 08.140 1989 05.939 07.981 1988 07.989 08.144 1987 13.377 13.429 1986 18.546 16.848 1985 17.517 19.094 1984 20.846 20.499 1983 20.371 17.493 1982 12.771 08.304 1981 05.639 08.295 1980 13.682 10.907 1979 14.189 08.297 1978 11.059 08.354 1977 03.529 08.260 1976 08.431 08.482 1975 13.095 09.255 1974 09.970 08.266 1973 15.974 10.108 1972 09.329 09.311 1971 11.798 08.591 1970 11.992 08.692 1969 11.520 08.823 1968 10.319 08.334 1967 08.979 07.797 1966 08.689 07.854 1965 15.046 10.820 1964 07.492 02.413 Water Flow Gages Lake Powell Water Level Graphs Glen Canyon Dam releases (SCADA) Water Holes Canyon above the mouth Colorado River at Lees Ferry Paria River near Kanab, UT Paria River at Lees Ferry, AZ Badger Creek below highway 89A near Vermillion Cliffs, AZ Tanner Wash below highway 89A near Bitter Springs, AZ House Rock Wash above Emmett Wash near Cliff Dwellers, AZ North Canyon near Cliff Dwellers, AZ Shinumo Wash in Twentynine Mile Canyon near Cedar Ridge, AZ Colorado River near river mile 30 Colorado River above Little Colorado River near Desert View, AZ Moenkopi Wash at Moenkopi, AZ Moenkopi Wash near Cameron, AZ Little Colorado River at Grand Falls, AZ Little Colorado River near Cameron, AZ Little Colorado River above the mouth near Desert View, AZ Colorado River near Grand Canyon, AZ Colorado River near Grand Canyon, AZ Bright Angel Creek near Grand Canyon, AZ Shinumo Creek Kanab Creek above the mouth near Supai, AZ Havasu Creek above the mouth near Supai, AZ Colorado River above National Canyon near Supai, AZ Colorado River above Diamond Creek near Peach Springs, AZ Lake Mead Water Level Graphs Presentations and Papers 2020 Hydrology, Operations and Reservoir Release presentation Hydrology, Operations and Reservoir Release presentation Hydrology, Operations and Reservoir Release 2019 Basin Hydrology, Reservoir Operations and 2020 Hydrograph Presentation 2018 Basin Hydrology, Water Years 2018-2019 Operations PPT Basin Hydrology, Reservoir Operations 2018 and 2019 Hydrograph How Will the Colorado Run? The Colorado River in a Warmer World Basin Hydrology, Water Years 2018-2019 Operations PPT Basin Hydrology, Reservoir Operations 2018 and 2019 Hydrograph PPT The 21st Century Colorado River Hot Drought and Implications for the Future PPT Basin Hydrology, Water Years 2018-2019 Operations PPT Basin Hydrology, Water Years 2018-2019 Operations PPT Basin Hydrology, Operations and 2018 Hydrograph PPT Basin Hydrology, Water Years 2018-2019 Operations PPT 2017 Basin Hydrology and Operations February 2017 Glen Canyon Montly Operational Coordination Call Basin Hydrology, and 2017-2018 Operations Analysis of Water Losses and Impacts to the Grand Canyon Ecosystem of the "Fill Mead First" Proposal and PPT Basin Hydrology, Operations and 2018 Hydrograph 2016 Basin Hydrology and Water Year (WY) 2017 Hydrograph Basin Hydrology, Operations, and 2017 Hydrograph TWG: Basin Hydrology, Operations, and 2017 Hydrograph Basin Hydrology, Operations, and 2017 Hydrograph Glen Canyon Dam Operations During Equalization Project 2: Streamflow, Water Quality, Sediment Transport, and Sand Budgets in the Colorado River Ecosystem 2015 California Drought Monitor Lake Mead Issues and Lower Basin Shortage Preparedness Lake Mead Issues and Lower Basin Shortage Preparedness - Presentation Basin Hydrology Operations, and 2016 Hydrograph Basin Hydrology Operations, and 2016 Hydrograph 2016 Annual Operating Plan Basin Hydrology and WY 2016 Hydrograph Hydrology Update and 2016 Hydrograph Water Quality in Lake Mead and Upstream Influences: Dissolved Oxygen during 2014 Basin Hydrology, Operations, and 2016 Hydrograph 2014 Basin Hydrology, Operations, and 2015 Hydrograph Basin Hydrology, Operations Basin Hydrology, Operations, and 2015 Hydrograph and AIF: Development of Water Year 2015 Hydrograph Basin Hydrology, Operations, and 2015 Hydrograph 2013 Basin Hydrology and Operations Colorado River Basin Hydrology and Projected Glen Canyon Dam Operations DOI/DOE FY14 Hydrograph Approved FY14 Hydrograph Basin Hydrology and Operations Colorado River Basin Water Supply and Demand Study Executive Summary--Pre-Production Copy of the Colorado River Basin Water Supply and Demand Study Colorado River Basin Water Study & Demand Study - Final Study Reports 2012 Basin Hydrology Basin Hydrology and Operations Flow Temp Turbidity 2011 Basin Hydrology Basin Hydrology Secure Water Act Section 9503 (c) - Water and Climate Change Bureau of Reclamation Updates 2010 Basin Hydrology and Operations Basin Hydrology and PPT 2009 Basin Hydrology PPT Basin Hydrology and PPT 2003 Topping et al. 2003. Computation and analysis of the instantaneous-discharge record for the Colorado River at Lees Ferry, Arizona, May 8, 1921 through September 30, 2000: U.S. Geological Survey Professional Paper 1677, 118 p. Other Stuff