state of the watershed: boulder creek, colorado sheila murphy

State of the Watershed:Boulder Creek, Colorado

Sheila Murphy

• Citizens’ guide to water quality past, present, future

• Informs Boulder’s Water Quality Strategic Plan

State of the Boulder Creek Watershed report

http://pubs.usgs.gov/circ/circ1284/

South Platte River Watershed

Boulder Creek Watershed

Mississippi River Watershed

Watershed: the area of land that drains into a water body

Boulder Creek Watershed

MAXIMUMELEVATION

4120 M

MINIMUMELEVATION

1480 M

CRETACEOUS SEDIMENTARY

PRECAMBRIAN GRANITE

PRECAMBRIAN METAMORPHIC

PLAINS

Climatic/ecological zones

Geology

FOOTHILLSMONTANESUBALPINEALPINE

From USGS National land cover data set

Land cover (1992)

Precipitation

Average daily discharge of Boulder Creek at Orodell gage, 1994-2004

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200

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June 2000

Discharge

October 2000

Width of blue line represents discharge

Water 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 regulations

Water quality from top to bottom

Water quality from top to bottom

Headwaters & 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 runoff

Water 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 bottom

Urban

Water 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 summer

Water quality from top to bottom

Lower Boulder Creek

Wastewater 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 fish

Water quality from top to bottom

Lower Boulder Creek

Problems 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 given

From 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 appearance

Solutions:

1905 to 1920 headlines from Boulder News-Herald

Analysis of historical water quality

Water quality: Pre-1858

Photograph 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 1870

Water development

Copyright 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 supply

Irrigation 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 background

Water quality: 1860s-1890s

Photograph courtesy Carnegie Branch Library for Local History, Boulder Historical Society Collection

Water quality: 1860s-1890s

Photograph 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 1890

Mining & water supply- Boulder Creek

Mining & water supply- Boulder Creek

Annual production of Boulder County (from USGS & Bureau of Mines)

Mining & water supply- Boulder Creek

Annual production of Boulder County (from USGS & Bureau of Mines)

Mining & water supply- Boulder Creek

Annual production of Boulder County (from USGS & Bureau of Mines)

Annual production of Boulder County (from USGS & Bureau of Mines)

Mining & water supply- Boulder Creek

Mining & water supply- Boulder Creek

Annual production of Boulder County (from USGS & Bureau of Mines)

• Boulder built first sewer line in 1895; discharged to settling basin, then to creek (at Scott Carpenter Park)

• Farmers downstream complained about sewage in creek

Typhoid cases in Boulder County, 1902-1980 (includes deaths)

Water quality: 1890s-1930s

• Typhoid tied to water contaminated by human waste ~1900

• Colorado began requiring reporting of typhoid in 1902

Water quality: 1930s-1950s

• Boulder’s first WWTP built in 1934; ineffective

From Chapman, 1934

Annual death rate in Coloradofrom typhoid fever, 1929-1931

• Other states boycotted South Platte Valley produce because crops irrigated with sewage

• 1948 Water Pollution Control Act: states responsible for control of water pollution

• New WWTP in 1957; quickly overloaded due to rapid population growth

Water quality: 1960s-1970s

• 1967 US Dept. of Interior study found Boulder Creek severely polluted, murky and gray, no fish below WWTP

• New WWTP in 1968, upgraded every few years

• U.S. Environmental Protection Agency est. 1970

• 1972 Clean Water Act required dischargers to meet water quality standards

Human waste and urban growth

1937

Human waste and urban growth

1957

Human waste and urban growth

1977

Human waste and urban growth

1997

Water quality: 1990s-today• Lower Boulder Creek on CO’s list of

impaired waters for un-ionized ammonia in 1992; Boulder WWTP upgraded to reduce ammonia discharged to creek

• Boulder Creek within Boulder on CO’s list of impaired waters for E coli in 2004

• Invasive species

• Hormones, steroids, drugs found below WWTP

• Reproductive disruption found in fish below WWTP; high female:male ratio

For more information…

Boulder Area Sustainability Information Network: www.BASIN.org

U.S. Geological Survey, Water Resources Discipline: http://water.usgs.gov

sfmurphy@usgs.gov