WATER QUALITY

Desired Future Condition for Water Quality Water quality with regards to dissolved oxygen, nutrient concentrations and cycling, turbidity, temperature, etc., is sufficient to support natural ecosystem functions, visitor safety and visitor experience to the extent feasible and consistent with the life history requirements of focal aquatic species. • Ecosystem-sustaining nutrient distribution, flux, and cycling. • Hydro-physical conditions and characteristics of the CRE necessary to sustain aquatic biota. • Acceptable water quality for human health and visitor experience.

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Updates Forebay temperature 2000-2016 https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR4_Radtke.pdf Forebay dissolved oxygen 2000-2016 https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR4_Radtke.pdf WQ field parameters measured monthly at forebay and quarterly throughout reservoir Depth Temperature Dissolved Oxygen pH Conductivity / TDS ORP Turbidity Chl a Secchi Depth Meteorological Information WQ samples sent for lab analysis Major ions pH Conductivity TDS, roe & soc TSS Alkalinity DOC OP TP NH3-N NO3+NO2-N TN Chl Phytoplankton / Zooplankton Metals (once per year, UT)

Links and Information GCMRC Annual Reports page Nutrients Page Temperature Page Water Quality PEP Reviews 2017 Water Quality PEP Final report of the 2001 Protocol Evaluation Panel for the Grand Canyon Monitoring and Research Center Integrated Water Quality Program (IWQP) Water Quality Gages Glen Canyon Dam near Page, AZ Colorado River at Lees Ferry Colorado River near river mile 30 Colorado River above Little Colorado River near Desert View, AZ Colorado River near Grand Canyon, AZ Bright Angel Creek Colorado River above National Canyon near Supai, AZ Colorado River above Diamond Creek near Peach Springs, AZ Papers and presentations 2022 Basin Hydrology, Operations and Water Quality Basin Hydrology, Water Quality, and Operations Basin Hydrology, Operations, and Water Quality Lake Powell Water Quality March 2021-March 2022 2021 Update on the Glen Canyon Dam/Lake Powell Dissolved Oxygen State-of-Practice Project 2020 Metalimnion low dissolved oxygen events in Lake Powell and their transport downstream of Glen Canyon Dam Deemer et al., 2020, Calcite precipitation in Lake Powell reduces alkalinity and total salt loading to the Lower Colorado River Basin: Limnology and Oceanography Dissolved Oxygen Downstream of Glen Canyon Dam, 2019 Lake Powell as a Regulator of Downstream Water Quality and Ecosystem Productivity 2018 Lake Powell Water Quality Program PPT GCMRC Science Updates PPT Stone et al., 2018, Abiotic Controls of Invasive Nonnative Fishes in the Little Colorado River, Arizona. The American Midland Naturalist 2017 Payn et al., 2017, A coupled metabolic-hydraulic model and calibration scheme for estimating of whole-river metabolism during dynamic flow conditions: Limnology and Oceanography: Methods, v.15, no.10, p. 847-866 Bernhardt et al. 2017. The metabolic regimes of flowing waters: Limnology and Oceanography Water Quality in Lake Powell and Its Influence on the Colorado River Below Glen Canyon Dam PPT 2016 Voichick et al. 2016. Water clarity of the Colorado River—Implications for food webs and fish communities: U.S. Geological Survey Fact Sheet 2016–3053, 4 p. Project 2: Streamflow, Water Quality, Sediment Transport, and Sand Budgets in the Colorado River Ecosystem 2015 Historical Physical and Chemical Data for Water in Lake Powell and from Glen Canyon Dam Releases, Utah-Arizona, 1964–2013 Water Quality in Lake Mead and Upstream Influences: Dissolved Oxygen during 2014 Streamflow, Water Quality, and Sediment Transport in the Colorado River Ecosystem Glen Canyon Physical Environment Update – Water Quality, Tributary Influences & Channel Analyses & Flows 2014 How the 2014 HFE affected water quality parameters such as dissolved oxygen (DO) and temperature below Glen Canyon Dam. 2012 Integrated Quality-of-Water Monitoring Flow Temp Turbidity 2010 Effects of Drought on Water Quality of Lake Powell and Glen Canyon Dam Releases Update on Water Quality and 2010 Sand Input 2009 Grand Canyon Monitoring and Research Center (GCMRC) Update Water Quality and Sediment, 2008 High Flow Experiment, and Integrated Flow, Temperature, and Sediment Modeling PPT Final Report of the Protocol Evaluation Panel for the GCMRC Integrated Water Quality Program 2006 Update on Water Quality of Lake Powell and Glen Canyon Dam Releases 2005 Reclamation to continue experimental operations at Glen Canyon Dam; Efforts address low dissolved oxygen levels below dam Modifying releases at Glen Canyon Dam to improve water quality in the Lees Ferry reach Rough operation of the turbines Increases the oxygenation of water going through the power plant Is damaging to the turbines Reclamation to continue experimental operations at Glen Canyon Dam to increase dissolved oxygen (2005) Oxygenation of the tailwater using the bypass tubes The Basin States have maintained that according to Sec 602a of the Colorado River Basin Project Act (1968), the bypass tubes at Glen Canyon Dam can only be used to avoid anticipated spills from Lake Powell. The Basin States have agreed to bypass at Glen Canyon Dam for HFEs on the condition that it be done as part of an experiment and not a management action or operational decision. Costs associated with any release that bypasses the powerplant for reasons other than to avoid a spill or for experimentation relating to HFEs would have to be borne by the GCDAMP (see DOI determination for costs of the 2004 BHBF). Adding power generation to the bypass tubes Allows for drawing water from deeper in Lake Powell where colder and more oxygenated water may be present. Generation at Outlet Glen Canyon Dam Plan of Study CRSP Power Peaking Capacity (March 1981) Other methods: Forebay diffusers Side stream super-saturation Aeration Turbine venting Surface water pumps (impellers) (Mobley Engineering: Hydropower Enhancement Technologies) Other Stuff