Hydrology

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Upper Colorado River Basin Hydrology The Upper Colorado River Basin regularly experiences significant year to year hydrologic variability. During the 17-year period 2000 to 2015, 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 3 out of the past 17 years. The period 2000-2016 is the lowest 17-year period since the closure of Glen Canyon Dam in 1963, with an average unregulated inflow of 8.57 maf, or 79% 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 2000-2016 period has ranged from a low of 2.64 maf (24% of average) in water year 2002 to a high of 15.97 maf (147% of average) in water year 2011. In water year 2016 unregulated inflow volume to Lake Powell was 9.62 maf (89% of average), which, though still below average, was significantly higher than inflows observed in 2012 and 2013 (45% and 47% of average, respectively). Under the current most probable forecast, the total water year 2017 unregulated inflow to Lake Powell is projected to be 13.5 maf (189% of average). [1]

Current Status	Current Operations	Inflow Forecasts and Model Projections

Reservoir Elevations Inflows to Lake Powell 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 Bureau of Reclamation- Snow Pack Report Upper Colorado Region Snow Pack Conditions Map 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

Water Flow Gages Lake Powell Water Level Graphs Glen Canyon Dam releases (SCADA) Colorado River at Lees Ferry Paria River near Kanab (US 89 bridge) Paria River at Lees Ferry Colorado River at 30 mile Colorado River above LCR LCR at Colorado River Colorado River at Bright Angel Creek Bright Angel Creek Shinumo Creek Colorado River abv Lava Canyon rm66 Colorado River bl rm127 Kanab Creek Havasu Creek Colorado River abv National Canyon Colorado River bl Diamond Creek Colorado River abv Spencer rm246 Lake Mead Water Level Graphs Presentations and Papers 2017 February 2017 Glen Canyon Montly Operational Coordination Call Basin Hydrology, and 2017-2018 Operations 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 AMWG: Basin Hydrology, Operations, and 2017 Hydrograph Glen Canyon Dam Operations During Equalization 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 AMWG: Basin Hydrology and WY 2016 Hydrograph TWG: Hydrology Update and 2016 Hydrograph Water Quality in Lake Mead and Upstream Influences: Dissolved Oxygen during 2014 Basin Hydrology, Operations, and 2016 Hydrograph Hydrology Update and 2016 Hydrograph 2014 Basin Hydrology, Operations, and 2015 Hydrograph Proposed 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 Other Stuff