Completion Reports

Permanent URI for this collectionhttps://hdl.handle.net/10217/195464

In addition to the report in this digital collection, two other reports, Irrigation Practices, Water Consumption, & Return Flows in Colorado's Lower Arkansas River Valley: Field and Model Investigations and Toward Optimal Water Management in Colorado's Lower Arkansas River Valley: Monitoring and Modeling to Enhance Agriculture and Environment were published jointly with the Colorado Agricultural Experiment Station and can be found in Colorado Agricultural Experiment Station digital collections.

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Open Access
Management of large wood in streams of Colorado's Front Range: a risk analysis based on physical, biological, and social factors
(Colorado State University. Libraries, 2017-03) Wohl, Ellen, author; Bestgen, Kevin, author; Bledsoe, Brian, author; Fausch, Kurt, author; Gooseff, Mike, author; Kramer, Natalie, author
Instream and floodplain wood can provide many benefits to river ecosystems, but can also create risks to inhabitants, infrastructure, property, and recreational users in the river corridor. In this report we outline a decision process for managing large wood, and particularly for assessing the relative benefits and risks associated with individual wood pieces and with accumulations of wood. This process can be applied at varying levels of effort, from a relatively cursory visual assessment to more detailed numerical modeling. Decisions of whether to retain, remove, or modify wood in a channel or on a floodplain are highly dependent on the specific context: the same piece of wood might require removal in a highly urbanized setting, for example, but provide sufficient benefits to justify retention in a natural area. Our intent is that the decision process outlined here can be used by individuals with diverse technical backgrounds and in a range of urban to natural river reaches.
Open Access
Using remote sensing assessments to document historical and current saved consumptive use (CU) on alfalfa and grass hayfields managed under full and partial-season irrigation regimes
(Colorado State University. Libraries, 2017-08) Cabot, Perry E., author; Vashisht, Aman, author; Chávez, José L., author
Open Access
Agricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 1 of 5
(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
Open Access
Reconstructing a water balance for north Crestone Creek: streamflow variability and extremes in a snowmelt dominated internal drainage basin
(Colorado State University. Libraries, 2013-05) Venable, Niah B. H., author; Fassnacht, Steven R., author
The San Luis Valley in Colorado is a semi-arid region that relies on streamflow from the surrounding mountain ranges for agricultural productivity and to recharge the important aquifer systems of the basin. The (North) Crestone Creek watershed is characteristic of the many small watersheds that drain the Sangre de Cristo Mountains on the eastern side of the valley providing water for local water users, wildlife, and augmentation of Rio Grande flows through the Closed Basin Project reclamation efforts. This study investigates the range of hydrologic variability and extremes in this area over the last 426 years using readily available historic hydrologic and paleo-climatic data derived from tree-rings and other sources. Streamflow and precipitation reconstructions were generated and compared to the historic period of observation. Water balance modeling was performed using historic and paleo-derived model inputs. The results of this study show that the drought conditions experienced in the San Luis Valley over the last decade are not unusual in the context of streamflow and precipitation reconstructions spanning hundreds of years. Past droughts were at least as intense as those in 1950 and 2002 and several droughts in the paleo-record were of much longer duration than any recorded in the instrumented period. These results are similar to those demonstrated in other paleo-hydrologic research from the western part of the San Luis Valley in Colorado and throughout the western United States. The water balance modeling provided a means to examine monthly changes to runoff and other hydrologic and state variables output by the model under differing past climate conditions. Together, the climate reconstructions and water balance model provide insight into regional water use sustainability and future development issues for a highly variable natural system.
Open Access
Water quality impacts of the mountain pine beetle infestation in the Rocky Mountain west
(Colorado State University. Libraries, 2014-11) McCray, John E., author; Bearup, Lindsay A., author; Rodriquez, Nicolas, author
The Mountain Pine Beetle (MPB) is the primary cause of insect-induced mortality in pine forests in western North America where some lodgepole forests have experienced more than 90% tree mortality. The implications of MPB infestation on water resources are particularly important in the Rocky Mountains, which serve as the source-water region for more than 60 million people. Two important potential watershed impacts are changes in the hydrologic cycle and water quality. While impacts on the hydrologic cycle have received some attention, the interconnection between these changes and the impacts of the widespread infestation on water quality are not well understood. This study uses a combination of field sample analysis and modeling based in Rocky Mountain National Park to address two potential MPB-driven effects on water quality: increased metal concentrations with ecotoxicological and human health ramifications and the changes in source water contributions to streamflow with possible implications for metal and carbon transport to downstream drinking water supplies. Previous work from the research team at Colorado School of Mines identified increased potential for disinfection byproduct formation at water treatment plants receiving water from heavily MPB-killed forests. These increases exhibited surprising seasonal trends that suggest that the transport of carbon to streams, and thus the flowpaths of water, may be different in MPB-killed forests. The first question was investigated by sequentially extracting trace metals from soils under trees with vary levels of impact, and using geochemical models to identify important process-level drivers of changes in metal mobility. Laboratory results identify redistribution of metals in soils under beetle-killed trees with greater mobilization potential for cadmium, and increases in zinc and copper, likely related to fluxes from needle leachate. Results also align with geochemical models and identify changes in organic carbon inputs as the primary driver of increased metal mobility. The second questions was addressed using a chemical hydrograph separation approach to partition streamwater into the fractions derived from groundwater, rain, and snow. Results demonstrate that fractional late-summer groundwater contributions from impacted watersheds are approximately 30 ± 15% greater after infestation and when compared with a neighboring watershed that experienced earlier and less-severe attack. Water budget analysis compared to published sap flux and remotely sensing studies reveals that this change is consistent with expected increases in groundwater from loss of transpiration across the watershed. A predictive statistical model (calibrated to observations within and around Rocky Mountain National Park) suggests that dissolved organic carbon concentrations in streams will be higher in areas where tree mortality is higher. Although, a strong statistical correlation was not found with the method used. Ultimately, this study identifies process-level hydrologic and biogeochemical changes that improve understanding of the vulnerability of Rocky Mountain water supplies to MPB outbreaks.
Open Access
Social network analysis workshop for water and resource management
(Colorado State University. Libraries, 2014-04) Herzog, Margaret T., author; Labadie, John W., author; Grigg, Neil S., author
Social network analysis (SNA) is a system for studying relationships and transactions between people, organizations, countries, and other entities. The purpose of this CWI project was to research and apply SNA techniques, then develop materials to provide a Fall 2013 half-day introductory workshop in Social Network Analysis for Water and Natural Resources Management at Colorado State University (CSU). The SNA workshop introduced interested students and professionals in engineering, natural resources, agriculture, and other scientific disciplines to complimentary analysis for human dimensions of their work and research through SNA principles and techniques. Complex social-ecological systems cannot be well-studied by only relying on technical analysis of the natural systems. SNA can help analyze how humans interact with resources and their environment and how their ties affect management choices. Social network structure can then be improved to enhance cooperation and innovation. CSU TILT instructional designers were involved in periodic workshop materials review with focus on implementing Research-Based Instructional (RBI) design. The workshop was marketed intensively for three weeks prior to delivery. The most effective means of participant recruitment were word of mouth and group emails, rather than posted flyers or campus-wide online calendars and newsletters. Instead of a traditional classroom, the SNA workshop was held in a conference room that permitted all attendees to sit facing one another around a large oval table, which enhanced participation and shared learning. Expert speakers with real world experience and warnings helped attendees better understand SNA application context and nuance. Providing two smaller sessions, rather than one larger offering, also allowed all attendees to participate more fully, and post-workshop evaluations from the first session were used to improve the second session by most evaluation measures. Follow-up included posting an SNA software demo online using CSU Echo 360 software and expanding other resources and discussion at the SNA Workshop Collaborative website to serve as an ongoing source for learning and sharing. Although not in the scope of the original project, in the Spring of 2014, a half-hour panel brief, a shortened seminar for undergraduates, and SNA software training for graduate students were also tested for SNA technical education merit. The SNA workshop will continue to be refined and tailored to specific CSU departments and programs, and it may be offered to more academic institutions and for other groups and agencies statewide and nationwide. Since attendees felt more time was needed to cover the many related topics and better learn SNA software tools for different applications, the SNA workshop will also be developed into a semester-long course and related textbook.
Open Access
Adjoint modeling to quantify stream flow changes due to aquifer pumping
(Colorado State University. Libraries, 2013-11) Neupauer, Roseanna M., author
As populations grow and demand for water increases, new sources of water must be found. If groundwater resources are developed to meet these growing demands, the increased pumping of aquifers should not reduce flows in rivers to levels that would limit the availability of water for drinking water supply, irrigation, and riparian habitat. Stream depletion is the term for the change in the river flow rate due to pumping in an aquifer that is hydraulically connected to the river. In many regions of the U.S., a new well cannot be sited until it is shown that pumping the new well will not cause substantial stream depletion. Numerical simulations are typically used to quantify stream depletion. In the standard approach, two numerical simulations are run—one without pumping and one with pumping in a well at the proposed location. In both simulations, the water flux between the river and aquifer is calculated, and the difference between these fluxes is the stream depletion due to pumping at the proposed well location. If multiple well locations are considered, one addition simulation must be run for each additional potential well location; thus, this approach can be inefficient for siting new wells. The goal this research was to develop an adjoint-based modeling approach to efficiently quantify stream depletion due to aquifer pumping. In a single simulation of an adjoint model, stream depletion is calculated for a well at any location in the aquifer; thus, it is computationally efficient when the number of well locations or possible well locations is large. The adjoint approach was developed to be used with standard groundwater flow simulators, and therefore can be applied in practice. The research included rigorous development of the adjoint equation for calculating stream depletion in confined and unconfined aquifers with various models of groundwater/surface water interaction, along with numerical simulations to verify the adjoint equation. In addition, we used the adjoint method to investigate the sensitivity of stream depletion to the hydraulic conductivity of the stream channel, a parameter which is known to be uncertain.
Open Access
HB12-1278 Study of the South Platte River alluvial aquifer
(Colorado State University. Libraries, 2013-12) Waskom, Reagan M., author
Open Access
Mountain basin hydrologic study
(Colorado State University. Libraries, 2018-12) Woolridge, Douglas D., author; Niemann, Jeffrey, author
A long-standing problem for the Rocky Mountain region is that traditional meteorology and flood hydrology methods appear to significantly overestimate floods based on comparisons to paleoflood evidence and regional peak streamflow statistics. The Colorado Water Conservation Board (CWCB), Colorado Division of Water Resources (DWR), and state of New Mexico are conducting a $1.5 million study to develop improved estimates of extreme precipitation for the two-state region. Concurrently, DWR has been working to improve flood hydrology methods for the mountain region. Traditional flood hydrology methods utilize low infiltration rates to model flood runoff solely by an infiltration-excess mechanism. However, a recent but preliminary examination of the Gross Reservoir Basin suggests that saturation-excess runoff might be important for extreme precipitation events. The objectives of this research project are: (1) to determine the importance of saturation-excess runoff production for large storms that affect the design and performance of dams and transportation infrastructure and (2) to develop a generalized model for runoff production in mountainous basins that can be used by consultants to perform hydrologic analysis of dams and transportation infrastructure. In-situ soil moisture observations indicate that south-facing slopes often reached saturation during the September 2013 flood while north-facing slopes usually did not. They further suggest that saturation occurred first at the bottom of the soil layer and proceeded upward. These observations are consistent with saturation-excess runoff production. The preliminary model results also indicate that saturation-excess runoff production was the primary runoff production mechanism in South Boulder Creek during the September 2013 flood. Additionally, the model results show that south-facing slopes approached saturation while the north-facing slopes did not.
Open Access
River adjustment and flood hazards on the Colorado Front Range
(Colorado State University. Libraries, 2016-08) Sholtes, Joel, author; Bledsoe, Brian, author
Stream power, a hydraulic metric representing the potential erosive energy of a flood, is relatively easy to estimate using remotely sensed data and can perform well in predicting channel response to floods. Using a dense network of peak discharge estimates from the 2013 Front Range floods and LiDAR-derived digital elevation models, we estimated stream power and related metrics at the reach scale along 16 stream and river segments in the Front Range of Colorado. Channel response to the floods was qualitatively categorized, and channel width and net erosion and deposition were measured at the reach scale. With these observations and measurements, we evaluated the relationship between stream power and geomorphic metrics and channel response to floods by applying statistical models and evaluating downstream trends in channel response. As a proof of concept, we applied the best performing empirical model to predict channel response to a range of flood frequencies. Finally, we participated in developing a framework for mapping the "fluvial hazard zone" within the State of Colorado, which will be further refined and piloted in 2017.
Open Access
Hydrologic and water quality collection for Colorado's Upper Arkansas River basin
(Colorado State University. Libraries, 2019-01) Gates, Timothy K., author; Niemann, Jeffrey D., author
Open Access
Constructing and testing a refined groundwater flow model for the LaSalle/Gilcrest area
(Colorado State University. Libraries, 2018-08) Bailey, Ryan T., author; Deng, Chenda, author
Open Access
Bark beetle impacts on remotely sensed evapotranspiration in the Colorado Rocky Mountains
(Colorado State University. Libraries, 2019-01) Knowles, John F., author; Molotoch, Noah P., author
Bark beetles represent a major ongoing forest disturbance throughout the southern Rocky Mountains with unknown implications for hydrological partitioning between the abiotic (evaporation) and biotic (transpiration) components of the total evapotranspiration (ET) flux. Since changes in ET are linked to both groundwater and surface water recharge processes, this scenario has the potential to affect water delivery to agricultural, industrial, and residential consumers downstream. Accordingly, this research used satellite remote sensing, eddy covariance, and hydrological modeling approaches to independently quantify the impact of bark beetles on growing season ET, the transpiration fraction of ET (T/ET), and streamflow across a range of spatial scales throughout the 144,462 km2 EPA Level III Southern Rocky Mountain ecoregion. The results of this work demonstrate statistically significant post-disturbance ET reductions between 9% (remote sensing) and 28% (eddy covariance) relative to pre-disturbance conditions. Further, commensurate decreases in transpiration and T/ET from disturbed areas suggest that the total ET flux was primarily sensitive to changes in transpiration. In the context of the water balance, the Variable Infiltration Capacity (VIC) hydrological model simulated decreased canopy interception and increased soil moisture as a result of beetle disturbance, which increased streamflow by 9%. Factoring in the number of grid cells that were disturbed, bark beetles decreased ET by 62,000 acre-feet and increased streamflow by 54,000 acre-feet between 2000 and 2013. These results will benefit water managers tasked with forecasting water resources from disturbed areas both now and in the future.
Open Access
Agricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 5 of 5
(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
Open Access
Snow depth measurement via time lapse photography and automated image recognition
(Colorado State University. Libraries, 2019-01) Brown, Kevin S., author; Fassnacht, Steven R., author
Seasonal snow is a crucial component of water supply in Colorado and the western United States. Measurement of snow accumulation through the winter and spring allows water managers to forecast water supply for the growing season and take actions to ease flooding and drought. The Natural Resources Conservation Service’s (NRCS) snow telemetry (SNOTEL) network provides real-time data at a high cost per station and at single points. An evaluation of existing field measurements of snow depth taken in 2009 and 2010 was undertaken to determine if fine resolution depth measurements are justified. Fassnacht et al. (in press) showed that the snow depth variability can be substantial even at fine resolution. However, these data required extensive labor to collect and only represented one measurement in time. A low-cost method to measure snow variability around these stations or in underrepresented areas could improve snow forecasts by quantifying the representativeness of data from the current network. To this end, we trialed a method combining time lapse photography and computer vision techniques to find snow depth at five sites in Colorado during water year 2018. Different site configurations were trialed, and a best operating procedure was determined. The data gathered were not more accurate than current ultrasonic or laser snow depth measurement technologies. However, the low cost and versatility of this method may make it more applicable in certain situations.
Open Access
Agricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 4 of 5
(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
Open Access
Agricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 3 of 5
(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
Open Access
Relative costs of new water supply options for Front Range cities: phase 2 report
(Colorado State University. Libraries, 2011-06) Kenney, Douglas S., author; Mazzone, Michael, author; Bedingfield, Jacob, author; Bergemann, Crystal, author; Jensen, Lindesy, author
The following report is the second (and final) installment of a project examining the costs associated with meeting future M&I (municipal and industrial) water supplies along Colorado's Front Range. As summarized in the recently updated Statewide Water Supply Initiative (SWSI 2010) reports, M&I water demand in Colorado is expected to climb by 600,000 to one million AF (AF) by 2050 (CWCB, 2010). Some mixture of three strategies will likely be necessary to meet this target: new water projects, water transfers (i.e., agricultural to urban reallocation), and conservation. Determining which option(s) is "best" is a complex matter that requires weighing highly case-specific opportunities, constraints, trade-offs, risks, uncertainties, and values. Presumably, among the most important considerations is economic cost. In this Phase 2 report, we continue our consideration of what is known and unknown about the economic costs of meeting these future water demands.
Open Access
Agricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 2 of 5
(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
Open Access
Hydrogeology and water quality studies in the Cache La Poudre Basin, Colorado
(Colorado State University. Libraries, 1969) Waltz, James P., author; Colorado State University, Natural Resources Center, publisher