Steering Committee Update Willard Spur Steering Committee August - PowerPoint PPT Presentation

Development of Water Quality Standards for Willard Spur Steering Committee Update Willard Spur Steering Committee August 16, 2011 Photo:Josh Noble

Monday, August 15, 2011 • Field tour

Monday, August 15, 2011 • Reviewed background – See memo • Reviewed objectives and approach • Reviewed sampling program – Methods, challenges, path forward • Discussed Willard Spur Dynamics • Discussed data and format

Inflow from Tributaries Weber River inflow (>1000 cfs) 7000 4206 4205.5 Increase of 2.9ft 6000 Decrease of 2.5 ft 4205 4204.5 5000 4204 Flow Rate (cfs) Elevation (ft) 4000 4203.5 4203 3000 4202.5 2000 4202 4201.5 1000 4201 0 4200.5 Bear River @Corinne Sum of BRMBR Outlets Willard Spur Water Level Source : http://waterdata.usgs.gov/nwis

Open or Closed Condition • Bear River flows vs. status of Willard Spur outlet 2011 peak flow CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED 8,000 7,000 Discharge (cfs) High GSL High GSL 6,000 5,000 4,000 ?? 3,000 2,000 1,000 0 Jun-84 Jun-87 Jun-90 Jun-93 Jun-96 Jun-99 Jun-02 Jun-05 Jun-08 Mar-85 Dec-85 Sep-86 Mar-88 Dec-88 Sep-89 Mar-91 Dec-91 Sep-92 Mar-94 Dec-94 Sep-95 Mar-97 Dec-97 Sep-98 Mar-00 Dec-00 Sep-01 Mar-03 Dec-03 Sep-04 Mar-06 Dec-06 Sep-07 Mar-09 YEAR Source : http://waterdata.usgs.gov/nwis USGS 10126000 BEAR RIVER NEAR CORINNE, UT Outlet status from satellite imagery

Tuesday, August 16 • Objective: – What water quality standards are appropriately protective of beneficial uses of Willard Spur waters as they relate to the proposed POTW discharge? • Working Hypothesis for Critical Condition – Outfall reaches open water, open water is closed off from Bear River Bay

Conceptual Models • Objective – Link the pressures that create stressors to the responses that may impact the beneficial uses – Visualize these relationships from the cause to the impacted use

Tuesday, August 16 • Pressure/Cause – PWRWTP discharge • Stressors – Nutrients, changed hydrology on mudflat • Responses – macroalgae, phragmites

Simplified Nutrient Conceptual Model Primary Impacts to Secondary Response Beneficial Uses Response Nutrient Load Loss of Habitat Decreased SAV Birds, Density and Altered Algal Fisheries, Cover Recreation Community Altered Food Web Decreased Birds, Light Fisheries, Availability Recreation Increased Organic Poor Water Decomposition Low Dissolved Quality Oxygen Recreation

Simplified Hydrology Conceptual Model Primary Impacts to Secondary Response Beneficial Uses Response Continuous Flows Loss of Habitat Loss of Birds, beneficial Fisheries, Wet soils Recreation vegetation due to invasives Altered Food Web Birds, Fisheries, Recreation Increased Habitat for Vegetation Predators Poor Water Quality Recreation

Tuesday, August 16 • Beneficial Use Impacts – Bird use and food web – Food web: fish, plants, macroinvertebrates

Studies – Water budget – Nutrient budget • Sediment/water exchange • Nutrients/macroalgae modeling • Nutrient limitation • Sediment burial – Food budget – Bird diet & carrying capacity – Fish species/population

Path Forward • Upcoming Science Panel meetings – September 22, 2011 – October 6, 2011 – November 3, 2011 – January 12, 2012