State of the Watershed: Boulder Creek, ColoradoSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9“Water quality” can include:Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Wastewater compounds found in Boulder CreekSlide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39For more information…State of the Watershed:Boulder Creek, ColoradoSheila Murphy•Citizens’ guide to water quality past, present, future•Informs Boulder’s Water Quality Strategic PlanState of the Boulder Creek Watershed reporthttp://pubs.usgs.gov/circ/circ1284/South Platte River WatershedBoulder Creek WatershedMississippi River WatershedWatershed: the area of land that drains into a water bodyBoulder Creek WatershedMAXIMUMELEVATION4120 MMINIMUMELEVATION1480 MCRETACEOUS SEDIMENTARYPRECAMBRIAN GRANITEPRECAMBRIAN METAMORPHICPLAINSClimatic/ecological zonesGeologyFOOTHILLSMONTANESUBALPINEALPINEFrom USGS National land cover data setLand cover (1992)PrecipitationAverage daily discharge of Boulder Creek at Orodell gage, 1994-20040100200300400500600700800199419951996199719981999200020012002200320040510152025 YEARMEAN DAILY STREAMFLOW,IN CUBIC FEET PER SECONDMEAN DAILY STREAMFLOW,IN CUBIC METERS PER SECOND 02-JUNE-199402-JULY-199822-JUNE-199522-JUNE-199620-JUNE-199723-JUNE-199909-JUNE-200008-JUNE-200101-JUNE-200201-JUNE-2003June 2000DischargeOctober 2000Width of blue line represents dischargeWater quality: The chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose“Water quality” can include:•Basic water quality variables (pH, dissolved oxygen)•Nutrients (phosphate, nitrate)•Bacteria•Trace metals (mercury, lead)•Pesticides•“Emerging contaminants” (wastewater-derived organic compounds)Water quality regulationsWater quality from top to bottomWater quality from top to bottomHeadwaters & mountains•Best water quality •Old mines not impacting water quality of most streams•Atmospheric deposition of nitrogen can decrease pH & act as fertilizer•Possible water quality concerns: Nederland WWTP, septic systems, recreation, road runoffWater quality from top to bottom•Diversions remove much of the water from the creek•High percentage of impervious surfaces•Boulder Creek within Boulder on Colorado’s 303(d) list for E. coli bacteria•Arsenic, lead, and copper highest in Boulder Creek during large storms Water quality from top to bottomUrbanWater quality from top to bottom•Wastewater Treatment Plant (WWTP) discharges ~17 million gallons per day to creek•WWTP effluent comprises 10-75% of the flow in the creek•WWTP contributes nutrients and organic contaminants to creek•Pollutant concentrations in creek typically lowest in early summerWater quality from top to bottomLower Boulder CreekWastewater compounds found in Boulder Creek•Metal-complexing agents (e.g., EDTA)•Surfactants (nonylphenol)•Plasticizers (bisphenol A)•Antimicrobials (triclosan)•Steroids (cholesterol)•Natural & synthetic hormones (estrogens) •Pharmaceutical drugs (codeine, caffeine, ibuprofen)Water quality from top to bottom•Diversions remove much of water (and pollutants) from creek•pH and dissolved oxygen fluctuate widely•High pH and temperature causes ammonia to shift to un-ionized ammonia gas, which is toxic to fishWater quality from top to bottomLower Boulder CreekProblems with evaluating long-term water quality changes:•Very little water quality data collected before 1960s•Different water quality parameters measured in the past and today•Analysis methods usually not givenFrom Ford and Moore, 1904•Estimate effects of dominant land and water uses•Number of cases of waterborne disease•Anecdotes and articles about water taste, smell, and appearanceSolutions:1905 to 1920 headlines from Boulder News-HeraldAnalysis of historical water qualityWater quality: Pre-1858Photograph copyright Denver Public Library•First evidence of humans in Colorado: 14,000 BC•Until 1800s AD, sparsely populated by Native Americans, who had little impact on landscape•Early 1800s: explorers and beaver trappers•Gold discovered in 1859; Gold Hill and Boulder founded•Settlers described Boulder Creek as “pure” and “full of fish”Boulder, Colorado, circa 1870Water developmentCopyright Denver Public Library•Settlers quickly realized Colorado’s dry climate required extensive water management to water crops and to have water year-round•First ditch decree filed on Boulder Creek in 1859 (oldest in South Platte Watershed)•Water diverted for domestic use, crop irrigation, mining•Reservoirs built to provide year-round water supplyIrrigation in Colorado; from Harper’s Weekly, 1874•Before 1875, Boulder residents carried water (untreated) from Boulder Creek, ditches, or shallow wells•Early settlers discharged sewage (untreated) to outhouses and cesspools•CO State Board of Health, 1877: “In rapidly growing towns the construction of sewers is often delayed until the subsoil is thoroughly saturated with disease-breeding filth.”South Boulder School, Eldorado Springs, ~1890, with outhouse in backgroundWater quality: 1860s-1890sPhotograph courtesy Carnegie Branch Library for Local History, Boulder Historical Society CollectionWater quality: 1860s-1890sPhotograph courtesy Carnegie Branch Library for Local History, Boulder Historical Society Collection•Dozens of gold & silver mines and mills, using chlorine, mercury, cyanide; chemicals and tailings discharged directly to creeks•Mining followed by forest fires, timber harvesting & tie drives, causing erosion•Boulder Creek described as having “a milk-like turbidity” which when consumed gave the “sensation of swallowing rope”Placer mining on Fourmile Creek, circa 1890Mining & water supply- Boulder CreekMining & water supply- Boulder CreekAnnual production of Boulder County (from USGS & Bureau of Mines)Mining & water supply- Boulder CreekAnnual production of Boulder County (from USGS & Bureau of Mines)Mining & water supply- Boulder CreekAnnual production of Boulder County (from USGS & Bureau of Mines)Annual production of Boulder County (from USGS & Bureau of Mines)Mining & water supply- Boulder CreekMining & water supply- Boulder CreekAnnual production of Boulder County (from USGS & Bureau of Mines)•Boulder built first sewer line in 1895;