Geology topics

James F. Bruce

Publications and source records attributed to James F. Bruce.

14 recordsLinked to original sources

USGS2018

Comparability among four invertebrate sampling methods and two multimetric indexes, Fountain Creek Basin, Colorado, 2010–2012

The U.S. Geological Survey (USGS), in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, analyzed previously collected invertebrate data to determine the comparability among four sampling methods and two versions (2010 and 2017) of the Colorado Benthic Macroinvertebrate Multimetric Index (MMI). For this study, annual macroinvertebrate samples were collected concurrently (in space and time) at 15 USGS surface-water gaging stations in the Fountain Creek Basin from 2010 to 2012 using four sampling methods. The USGS monitoring project in the basin uses two of the methods and the Colorado Department of Public Health and Environment recommends the other two. These methods belong to two distinct sample types, one that targets single habitats and one that targets multiple habitats. The study results indicate that there are significant differences in MMI values obtained from the single-habitat and multihabitat sample types but methods from each program within each sample type produced comparable values. This study also determined that MMI values calculated by different versions of the Colorado Benthic Macroinvertebrate MMI are indistinguishable. This indicates that the Colorado Department of Public Health and Environment methods are comparable with the USGS monitoring project methods for single-habitat and multihabitat sample types. This report discusses the direct application of the study results to inform the revision of the existing USGS monitoring project in the Fountain Creek Basin.

Colorado↗

USGS2018

Changes in biological communities of the Fountain Creek Basin, Colorado, 2003–2016, in relation to antecedent streamflow, water quality, and habitat

The analysis described in this report is part of a longterm project monitoring the biological communities, habitat, and water quality of the Fountain Creek Basin. Biology, habitat, and water-quality data have been collected at 10 sites since 2003. These data include annual samples of aquatic invertebrate communities, fish communities, water quality, and quantitative riverine habitat. This report examines trends in biological communities from 2003 to 2016 and explores relationships between biological communities and abiotic variables (antecedent streamflow, physical habitat, and water quality). Six biological metrics (three invertebrate and three fish) and four individual fish species were used to examine trends in these data and how streamflow, habitat, and (or) water quality may explain these trends. The analysis of 79 trends shows that the majority of significant trends decreased over the trend period. Overall, 19 trends before adjustments for streamflow in the fish (12) and invertebrate (7) metrics were all decreasing except for the metric Invertebrate Species Richness at the most upstream site in Monument Creek. Seven of these trends were explained by streamflow and four trends were revealed that were originally masked by variability in antecedent streamflow. Only two sites (Jimmy Camp Creek at Fountain, CO and Fountain Creek near Pinon, CO) had no trends in the fish or invertebrate metrics. Ten of the streamflow-adjusted trends were explained by habitat, one was explained by water quality, and five were not explained by any of the variables that were tested. Overall, from 2003 to 2016, all the fish metric trends were decreasing with an average decline of 40 percent, and invertebrate metrics decreased on average by 9.5 percent. A potential peak streamflow threshold was identified above which there is severely limited production of age-0 flathead chub (Platygobio gracilis).

Colorado↗

USGS2016

Characterization and relation of precipitation, streamflow, and water-quality data at the U.S. Army Garrison Fort Carson and Piñon Canyon Maneuver Site, Colorado, water years 2013–14

To evaluate the influence of military training activities on streamflow and water quality, the U.S. Geological Survey, in cooperation with the U.S. Department of the Army, began a hydrologic data collection network on the U.S. Army Garrison Fort Carson in 1978 and on the Piñon Canyon Maneuver Site in 1983. This report is a summary and characterization of the precipitation, streamflow, and water-quality data collected at 43 sites between October 1, 2012, and September 30, 2014 (water years 2013 and 2014). Variations in the frequency of daily precipitation, seasonal distribution, and seasonal and annual precipitation at 5 stations at the U.S. Army Garrison Fort Carson and 18 stations at or near the Piñon Canyon Maneuver Site were evaluated. Isohyetal diagrams indicated a general pattern of increase in total annual precipitation from east to west at the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site. Between about 54 and 79 percent of daily precipitation was 0.1 inch or less in magnitude. Precipitation events were larger and more frequent between July and September. Daily streamflow data from 16 sites were used to evaluate temporal and spatial variations in streamflow for the water years 2013 and 2014. At all sites, median daily mean streamflow for the 2-year period ranged from 0.0 to 9.60 cubic feet per second. Daily mean streamflow hydrographs are included in this report. Five sites on the Piñon Canyon Maneuver Site were monitored for peak stage using crest-stage gages. At the Piñon Canyon Maneuver Site, five sites had a stage recorder and precipitation gage, providing a paired streamflow-precipitation dataset. There was a statistically significant correlation between precipitation and streamflow based on Spearman’s rho correlation (rho values ranged from 0.17 to 0.35). Suspended-sediment samples were collected in April through October for water years 2013–14 at one site at the U.S. Army Garrison Fort Carson and five sites at the Piñon Canyon Maneuver Site. Suspended-sediment-transport curves were used to illustrate the relation between streamflow and suspended-sediment concentration. All these sediment-transport curves showed a streamflow dependent suspended-sediment concentration relation except for the U.S. Geological Survey station Bent Canyon Creek at mouth near Timpas, CO. Water-quality data were collected and reported from seven sites on the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site during water years 2013–14. Sample results exceeding an established water-quality standard were identified. Selected water-quality properties and constituents were stratified to compare spatial variation among selected characteristics using boxplots. Trilinear diagrams were used to classify water type based on ionic concentrations of water-quality samples collected during the study period. At the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site, 27 samples were classified as very hard or brackish. Seven samples had a lower hardness character relative to the other samples. Four of those nine samples were collected at two U.S. Geological Survey stations (Turkey Creek near Fountain, CO, and Little Fountain Creek above Highway 115 at Fort Carson, CO), which have different geologic makeup. Three samples collected at the Piñon Canyon Maneuver Site had a markedly lower hardness likely because of dilution from an increase in streamflow.

Colorado↗

USGS2016

Macroinvertebrate community sample collection methods and data collected from Sand Creek and Medano Creek, Great Sand Dunes National Park and Preserve, Colorado, 2005–07

This report provides a table of site descriptions, sample information, and semiquantitative aquatic macroinvertebrate data from 105 samples collected between 2005 and 2007 from 7 stream sites within the Sand Creek and Medano Creek watersheds in Great Sand Dunes National Park and Preserve, Saguache County, Colorado. Additionally, a short description of sample collection methods and laboratory sample processing procedures is presented. These data were collected in anticipation of assessing the potential effects of fish toxicants on macroinvertebrates.

Colorado↗

USGS2014

Comparability among four invertebrate sampling methods, Fountain Creek Basin, Colorado, 2010-2012

The U.S. Geological Survey, in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, designed a study to determine if sampling method and sample timing resulted in comparable samples and assessments of biological condition. To accomplish this task, annual invertebrate samples were collected concurrently using four sampling methods at 15 U.S. Geological Survey streamflow gages in the Fountain Creek basin from 2010 to 2012. Collectively, the four methods are used by local (U.S. Geological Survey cooperative monitoring program) and State monitoring programs (Colorado Department of Public Health and Environment) in the Fountain Creek basin to produce two distinct sample types for each program that target single-and multiple-habitats. This study found distinguishable differences between single-and multi-habitat sample types using both community similarities and multi-metric index values, while methods from each program within sample type were comparable. This indicates that the Colorado Department of Public Health and Environment methods were compatible with the cooperative monitoring program methods within multi-and single-habitat sample types. Comparisons between September and October samples found distinguishable differences based on community similarities for both sample types, whereas only differences were found for single-habitat samples when multi-metric index values were considered. At one site, differences between September and October index values from single-habitat samples resulted in opposing assessments of biological condition. Direct application of the results to inform the revision of the existing Fountain Creek basin U.S. Geological Survey cooperative monitoring program are discussed.

Colorado↗

USGS2014

Groundwater and surface-water interaction and potential for underground water storage in the Buena Vista-Salida Basin, Chaffee County, Colorado, 2011

By 2030, the population of the Arkansas Headwaters Region, which includes all of Chaffee and Lake Counties and parts of Custer, Fremont, and Park Counties, Colorado, is forecast to increase about 73 percent. As the region’s population increases, it is anticipated that groundwater will be used to meet much of the increased demand. In September 2009, the U.S. Geological Survey, in cooperation with the Upper Arkansas Water Conservancy District and with support from the Colorado Water Conservation Board; Chaffee, Custer, and Fremont Counties; Buena Vista, Cañon City, Poncha Springs, and Salida; and Round Mountain Water and Sanitation District, began a 3-year study of groundwater and surface-water conditions in the Buena Vista-Salida Basin. This report presents results from the study of the Buena Vista-Salida Basin including synoptic gain-loss measurements and water budgets of Cottonwood, Chalk, and Browns Creeks, changes in groundwater storage, estimates of specific yield, transmissivity and hydraulic conductivity from aquifer tests and slug tests, an evaluation of areas with potential for underground water storage, and estimates of stream-accretion response-time factors for hypothetical recharge and selected streams in the basin. The four synoptic measurements of flow of Cottonwood, Chalk, and Browns Creeks, suggest quantifiable groundwater gains and losses in selected segments in all three perennial streams. The synoptic measurements of flow of Cottonwood and Browns Creeks suggest a seasonal variability, where positive later-irrigation season values in these creeks suggest groundwater discharge, possibly as infiltrated irrigation water. The overall sum of gains and losses on Chalk Creek does not indicate a seasonal variability but indicates a gaining stream in April and August/September. Gains and losses in the measured upper segments of Chalk Creek likely are affected by the Chalk Cliffs Rearing Unit (fish hatchery). Monthly water budgets were estimated for selected segments of five perennial streams (Cottonwood, North Cottonwood, Chalk, and Browns Creeks, and South Arkansas River) in the Buena Vista-Salida Basin for calendar year 2011. Differences between reported diversions and estimated crop irrigation requirements were used to estimate groundwater recharge in the areas irrigated by water supplied from the diversions. The amount of groundwater recharge in all the basins varied monthly; however, the greatest amount of recharge was during June and July for Cottonwood, North Cottonwood, and Chalk Creeks and South Arkansas River. The greatest amount of recharge in 2011 in Browns Creek occurred in July and August. The large seasonal fluctuations of groundwater near irrigated areas in the Buena Vista-Salida Basin indicate that the increased groundwater storage resulting from infiltration of surface-water diversions has dissipated by the following spring. Areas within the Buena Vista-Salida Basin with the potential for underground storage were identified using geographic information system data, including topographic, geologic, and hydrologic data, excluding the mountainous areas that border the Buena Vista-Salida Basin and igneous and metamorphic rock outcrop areas. The areas that met the selection criteria for underground water storage are located on terrace deposits near the Arkansas River and adjacent to its major tributaries. The selected areas also contain much of the irrigated land within the basin; consequently, irrigation ditches and canals could provide a means of conveying water to potential recharge sites.

Colorado↗

USGS2013

Barriers impede upstream spawning migration of flathead chub

Many native cyprinids are declining throughout the North American Great Plains. Some of these species require long reaches of contiguous, flowing riverine habitat for drifting eggs or larvae to develop, and their declining populations have been attributed to habitat fragmentation or barriers (e.g., dams, dewatered channels, and reservoirs) that restrict fish movement. Upstream dispersal is also needed to maintain populations of species with passively drifting eggs or larvae, and prior researchers have suggested that these fishes migrate upstream to spawn. To test this hypothesis, we conducted a mark–recapture study of Flathead Chub Platygobio gracilis within a 91-km reach of continuous riverine habitat in Fountain Creek, Colorado. We measured CPUE, spawning readiness (percent of Flathead Chub expressing milt), and fish movement relative to a channel-spanning dam. Multiple lines of evidence indicate that Flathead Chub migrate upstream to spawn during summer. The CPUE was much higher at the base of the dam than at downstream sites; the seasonal increases in CPUE at the dam closely tracked seasonal increases in spawning readiness, and marked fish moved upstream as far as 33 km during the spawning run. The upstream migration was effectively blocked by the dam. The CPUE of Flathead Chub was much lower upstream of the OHDD than at downstream sites, and <0.2% of fish marked at the dam were recaptured upstream. This study provides the first direct evidence of spawning migration for Flathead Chub and supports the general hypothesis that barriers limit adult dispersal of these and other plains fishes.

Colorado↗

USGS2010

Macroinvertebrate and algal community sample collection methods and data collected at selected sites in the Eagle River watershed, Colorado, 2000-07

State and local agencies are concerned about the effects of increasing urban development and human population growth on water quality and the biological condition of regional streams in the Eagle River watershed. In response to these needs, the U.S. Geological Survey initiated a study in cooperation with the Colorado River Water Conservation District, Eagle County, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, Colorado Department of Transportation, City of Aurora, Town of Eagle, Town of Gypsum, Town of Minturn, Town of Vail, Vail Resorts, Colorado Springs Utilities, Denver Water, and the U.S. Department of Agriculture Forest Service. As part of this study, previously collected macroinvertebrate and algal data from the Eagle River watershed were compiled. This report includes macroinvertebrate data collected by the U.S. Geological Survey and(or) the U.S. Department of Agriculture Forest Service from 73 sites from 2000 to 2007 and algal data collected from up to 26 sites between 2000 and 2001 in the Eagle River watershed. Additionally, a brief description of the sample collection methods and data processing procedures are presented.

Data Series↗

USGS2010

Temporal change in biological community structure in the Fountain Creek basin, Colorado, 2001-2008

In 2001, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, began a study to better understand the relations between environmental characteristics and biological communities in the Fountain Creek basin in order to aide water-resource management and guide future monitoring activities. To accomplish this task, environmental (streamflow, habitat, and water chemistry) and biological (fish and macroinvertebrate) data were collected annually at 24 sites over a 6- or 8-year period (fish, 2003 to 2008; macroinvertebrates, 2001 to 2008). For this report, these data were first analyzed to determine the presence of temporal change in macroinvertebrate and fish community structure among years using nonparametric multivariate statistics. Where temporal change in the biological communities was found, these data were further analyzed using additional nonparametric multivariate techniques to determine which subset of selected streamflow, habitat, or water-chemistry variables best described site-specific changes in community structure relative to a gradient of urbanization. This study identified significant directional patterns of temporal change in macroinvertebrate and fish community structure at 15 of 24 sites in the Fountain Creek basin. At four of these sites, changes in environmental variables were significantly correlated with the concurrent temporal change identified in macroinvertebrate and fish community structure (Monument Creek above Woodmen Road at Colorado Springs, Colo.; Monument Creek at Bijou Street at Colorado Springs, Colo.; Bear Creek near Colorado Springs, Colo.; Fountain Creek at Security, Colo.). Combinations of environmental variables describing directional temporal change in the biota appeared to be site specific as no single variable dominated the results; however, substrate composition variables (percent substrate composition composed of sand, gravel, or cobble) collectively were present in 80 percent of the environmental variable subsets that were significantly correlated with temporal change in the macroinvertebrate and fish community structure. Other important environmental variables related to temporal change in the biological community structure included those describing channel form (streambank height) and streamflow (normalized annual mean daily flow, high flood-pulse count). Site-specific results from this study were derived from a relatively small number of observations (6 or 8 years of data); therefore, additional years of data may reveal other sites with temporal change in biological community structure, or could define stronger and more consistent linkages between environmental variables and observed temporal change. Likewise current variable subsets could become weaker. Nonetheless, there were several sites where temporal change was detected in this study that could not be explained by the available environmental variables studied herein. Modification of current data-collection activities may be necessary to better understand site-specific temporal relations between biological communities and environmental variables.

Scientific Investigations Report↗

USGS2010

Macroinvertebrate-based assessment of biological condition at selected sites in the Eagle River watershed, Colorado, 2000-07

The U.S. Geological Survey (USGS), in cooperation with the Colorado River Water Conservation District, Eagle County, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, Colorado Department of Transportation, City of Aurora, Town of Eagle, Town of Gypsum, Town of Minturn, Town of Vail, Vail Resorts, Colorado Springs Utilities, Denver Water, and the U.S. Department of Agriculture Forest Service (FS), compiled macroinvertebrate (73 sites, 124 samples) data previously collected in the Eagle River watershed from selected USGS and FS studies, 2000-07. These data were analyzed to assess the biological condition (that is, biologically ?degraded? or ?good?) at selected sites in the Eagle River watershed and determine if site class (for example, urban or undeveloped) described biological condition. An independently developed predictive model was applied to calculate a site-specific measure of taxonomic completeness for macroinvertebrate communities, where taxonomic completeness was expressed as the ratio of observed (O) taxa to those expected (E) to occur at each site. Macroinvertebrate communities were considered degraded at sites were O/E values were less than 0.80, indicating that at least 20 percent of expected taxa were not observed. Sites were classified into one of four classes (undeveloped, adjacent road or highway or both, mixed, urban) using a combination of riparian land-cover characteristics, examination of topographic maps and aerial imagery, screening for exceedances in water-quality standards, and best professional judgment. Analysis of variance was used to determine if site class accounted for variability in mean macroinvertebrate O/E values. Finally, macroinvertebrate taxa observed more or less frequently than expected at urban sites were indentified. This study represents the first standardized assessment of biological condition of selected sites distributed across the Eagle River watershed. Of the 73 sites evaluated, just over half (55 percent) were considered in good biological condition (O/E greater than 0.80). The remaining sites were either consistently biologically degraded (30 percent; O/E less than 0.80) or varied annually between good and degraded condition (15 percent; O/E is less than or greater than 0.80). Sites primarily affected by urbanization were among the most severely degraded (lowest O/E values) when compared to other site classes. Although most urban sites were among the most severely degraded (lowest O/E values), a few sites had nearly intact macroinvertebrate communities (O/E near 1.0). Similar observations were noted among sites classified as mixed. Thirteen macroinvertebrate taxa were indentified that occurred more or less frequently than expected at urban sites. Additionally, six other taxa were impartial (tolerant) to the same conditions. Combined, these 19 taxa provide an opportunity to enhance the interpretation of future studies in the Eagle River watershed, but will require better insight into the responses of these taxa to specific stressors. Understanding the sources of variability affecting biological condition along with why some sites expected to be degraded, but showed otherwise, will have clear implications for mitigation efforts. Integrating results of this study with field and laboratory investigations will greatly enhance the ability to identify causal factors affecting biological condition at degraded sites, the logical next step. Information generated from such integrative studies will be imperative for well targeted mitigation efforts in the Eagle River watershed.

Scientific Investigations Report↗

USGS2007

Urban-Related Environmental Variables and Their Relation with Patterns in Biological Community Structure in the Fountain Creek Basin, Colorado, 2003-2005

In 2003, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, began a study to evaluate the influence of urbanization on stream ecosystems. To accomplish this task, invertebrate, fish, stream discharge, habitat, water-chemistry, and land-use data were collected from 13 sites in the Fountain Creek basin from 2003 to 2005. The Hydrologic Index Tool was used to calculate hydrologic indices known to be related to urbanization. Response of stream hydrology to urbanization was evident among hydrologic variables that described stormflow. These indices included one measurement of high-flow magnitude, two measurements of high-flow frequency, and one measurement of stream flashiness. Habitat and selected nonstormflow water chemistry were characterized at each site. Land-use data were converted to estimates of impervious surface cover and used as the measure of urbanization annually. Correlation analysis (Spearman?s rho) was used to identify a suite of nonredundant streamflow, habitat, and water-chemistry variables that were strongly associated (rho > 0.6) with impervious surface cover but not strongly related to elevation (rho < 0.60). An exploratory multivariate analysis (BIO-ENV, PRIMER ver 6.1, Plymouth, UK) was used to create subsets of eight urban-related environmental variables that described patterns in biological community structure. The strongest and most parsimonious subset of variables describing patterns in invertebrate community structure included high flood pulse count, lower bank capacity, and nutrients. Several other combinations of environmental variables resulted in competing subsets, but these subsets always included the three variables found in the most parsimonious list. This study found that patterns in invertebrate community structure from 2003 to 2005 in the Fountain Creek basin were associated with a variety of environmental characteristics influenced by urbanization. These patterns were explained by a combination of hydrologic, habitat, and water-chemistry variables. Fish community structure showed weaker links between urban-related environmental variables and biological patterns. A conceptual model was developed that showed the influence of urban-related environmental variables and their relation to fish and invertebrate assemblages. This model should prove helpful in guiding future studies on the impacts of urbanization on aquatic systems. Long-term monitoring efforts may be needed in other drainages along the Front Range of Colorado to link urban-related variables to aquatic communities in transition zone streams.

Scientific Investigations Report↗

USGS2002

Characterization and analysis of temporal and spatial variations in habitat and macroinvertebrate community structure, Fountain Creek basin, Colorado Springs and vicinity, Colorado, 1998-2001

The Fountain Creek Basin in and around Colorado Springs, Colorado, is affected by various land- and water-use activities. Biological, hydrological, water-quality, and land-use data were collected at 10 sites in the Fountain Creek Basin from April 1998 through April 2001 to provide a baseline characterization of macroinvertebrate communities and habitat conditions for comparison in subsequent studies; and to assess variation in macroinvertebrate community structure relative to habitat quality. Analysis of variance results indicated that instream and riparian variables were not affected by season, but significant differences were found among sites. Nine metrics were used to describe and evaluate macroinvertebrate community structure. Statistical analysis indicated that for six of the nine metrics, significant variability occurred between spring and fall seasons for 60 percent of the sites. Cluster analysis (unweighted pair group method average) using macroinvertebrate presence-absence data showed a well-defined separation between spring and fall samples. Six of the nine metrics had significant spatial variation. Cluster analysis using Sorenson?s Coefficient of Community values computed from macroinvertebrate density (number of organisms per square meter) data showed that macroinvertebrate community structure was more similar among tributary sites than main-stem sites. Canonical correspondence analysis identified a substrate particle-size gradient from site-specific species-abundance data and environmental correlates that decreased the 10 sites to 5 site clusters and their associated taxa.

Water-Resources Investigations Report↗

USGS2002

Evaluation of water quality, suspended sediment, and stream morphology with an emphasis on effects of stormflow on Fountain and Monument Creek basins, Colorado Springs and vicinity, Colorado, 1981 through 2001

This report documents water quality and suspended sediment with an emphasis on evaluating the effects of stormflow on Fountain Creek Basin in the vicinity of Colorado Springs, Colorado. Water-quality data collected at 11 sites between 1981 and 2001 were used to evaluate the effects of stormflow on water quality. Suspended-sediment data collected at seven sites from 1998 through 2001 were used to evaluate effects of stormflow on suspended-sediment concentrations, discharges, and yields. Data were separated into three flow regimes: base flow, normal flow, and stormflow. A comparison of stormwater-quality concentrations measured between 1981 and 2001 to Colorado acute instream standards indicated that, except for isolated occurrences, stormwater quality met acute instream standards. At several sites, 5-day biochemical oxygen demand, fecal coliform, and selected nutrient concentrations tended to be highest during stormflow and lowest during base flow. Dissimilar to the other nutrients, dissolved nitrite plus nitrate concentrations generally were highest during base flow and lowest during stormflow. Most dissolved trace-element concentrations associated with stormflow decreased or showed little change compared to base flow. However, median concentrations of total copper, iron, lead, nickel, manganese, and zinc for stormflow samples generally were much larger than nonstorm samples. The substantially larger concentrations of total copper, iron, lead, nickel, manganese, and zinc measured at site 5800 during stormflow as compared to other sites indicates a relatively large source of these metals in the reach between sites 5530 and 5800. Semi-volatile organic compounds in samples collected during stormflow were detected relatively infrequently at the four sites monitored; however, analysis of pesticide data collected during stormflow showed a relatively frequent detection of pesticides at low levels. Nitrogen, phosphorus, and particulate trace-element loads substantially increased during stormflow. Suspended-sediment concentrations, discharges, and yields associated with stormflow were significantly greater than during normal flow. Depending on the site and year, suspended-sediment concentrations associated with storm-flow generally were 3 to10 times greater than concentrations measured during normal flow, and suspended-sediment discharges were usually more than 10 times greater during stormflow. The April through October cumulative suspended-sediment discharges and streamflows were largest in 1999 at all sites. Although large spatial variations in suspended-sediment yields occurred during normal flows, the suspended-sediment yields associated with stormflow generally were more than 10 times greater than the suspended-sediment yields that occurred during normal flow. The smallest suspended-sediment yields generally were less than 1 ton per day per square mile during stormflow. The largest suspended-sediment yields occurred at sites located in the Cottonwood Creek Basin and were greater than 10 tons per day per square mile.

Colorado↗

USGS2002

Evaluation of water quality, suspended sediment, and stream morphology with an emphasis on effects of stormwater on Fountain and Monument Creek basins, Colorado Springs and vicinity, Colorado, 1981-2001

Water-Resources Investigations Report↗