Search USGS⌕ Search

Geology topics

S. R. Blakely

Publications and source records attributed to S. R. Blakely.

5 recordsLinked to original sources
USGS1985

Selected hydrologic data for the south Platte River through Denver, Colorado

The U.S. Geological Survey, in cooperation with the cities of Littleton and Englewood, Colorado, studied the effects of the discharge of treated effluent from the Bi-City Waste Water Treatment Plant on low-flow conditions of the South Platte River. An 18-mile reach of the South Platte River, beginning below Chatfield Reservoir, through the Denver metropolitan area was studied. Chatfield Reservoir was used to regulate the flow of the South Platte River on four occasions between October 1982 and January 1984. Each flow-regulation period was used to achieve a stable, low-flow condition. Data collection during low flow allowed for the study of waste assimilation during both warm- and cold-water conditions. Water quality, streamflow, channel geometry, traveltime, mixing-zone, reaeration, and benthic-oxygen demand data were collected at selected instream, tributary, and effluent sites. This report presents data collected during four periods of low flow along the South Platte River. (USGS)

Open-File Report↗
USGS1985

Effects of wastewater effluent on the South Platte River from Littleton to Denver

The U.S. Geological Survey 's one-dimensional steady-state water quality model was used to investigate the effects of the effluent from the Bi-City WWTP (Wastewater Treatment Plant) on the South Platte River. The Bi-City WWTP is operated by the Cities of Littleton and Englewood. The model was calibrated from a 14.5 mile reach for 5-day carbonaceous biochemical oxygen demand, organic, ammonia, nitrite and nitrate using data collected during September 1983. Model verification was completed using data collected during October 1982 and January 1984 for all constituents except nitrite nitrogen. Nitrite nitrogen could not be verified for the cold temperature conditions of January of 1984. Measured benthic sediment oxygen demand used in model ranged from 1.01 to 2.77 grams per square meter per day. Model simulations were made for an estimated 7-day, 10-year discharge of 18 cubic feet per second, upstream from the outfall of the WWTP. Two groups of simulations were made for both warm and cold temperature conditions. In the first group of simulation variations were made in effluent 5-day carbonaceous biochemical oxygen demand concentrations and flow rates. The second group of simulations varied the amount of nitrogen discharged as ammonia and nitrate. The extent of the mixing zone downstream of the WWTP outfall was determined by injecting Rhodamine WT dye into the effluent. The mixing zone was found to extend 0.8 miles during low-flow conditions. (USGS)

Water-Resources Investigations Report↗
USGS1984

Hydrologic data for the Larimer-Weld regional water-monitoring program, Colorado, 1975-82

The Larimer-Weld, Colorado, regional Monitoring Program was begun in 1976 to provide information on the quality and quantity of the surface-water resources in the area. Three stations on the big Thompson River and five stations on the Cache La Poudre River were selected for a data-collection network. Four previously established stations were added to complete the data-collection network: Horsetooth Reservoir, Joe Wright Creek above and below Joe Wright Reservoir, and Michigan River near Cameron Pass. Station description, location, and period of record are given for each station. A statistical summary of the water-quality data for each station is tabulated. Frequency of occurrence is given at the 95th, 75th, 50th, and 25th percentiles. Monthly water-quality data and daily average streamflow data are tabulated for each streamflow station for which this data was collected; Monthly contents data are presented for Horsetooth Reservoir. All data tabulated and summarized are from the period October 1, 1975, through September 30, 1982. (USGS)

Open-File Report↗
USGS1984

Analysis of urban storm-runoff data and the effects on the South Platte River, Denver metropolitan area, Colorado

Denver was selected for inclusion in the Nationwide Urban Runoff Program, sponsored by the U.S. Environmental Protection Agency and the U.S. Geological Survey. This report, prepared in cooperation with the Denver Regional council of governments, contains a synopsis of previous urban runoff studies in the Denver metropolitan area. The report includes a description of the monitored basins, a summary of storm runoff-to-rainfall ratios and estimates of impervious retention, and constituent loads and concentrations from seven small basins. The data from six small and five tributary basins to the South Platte River are analyzed using regression analysis, resulting in two sets of regression equations to predict storm runoff volume and selected constituent loads. The regression equations may be used to estimate storm-runoff volume and constituent loads from unmonitored basins from 15 to 16,000 acres with effective impervious areas of 15 to 90 percent. The effects of urban runoff on the South Platte River in the Denver area are described in three ways. The three methods indicated that storm runoff was a significant contributor of total suspended solids, total organic carbon, total lead, and total zinc to the South Platte River.

Colorado↗