Research

Investigator(s):
[email] Amy Pruden, Colorado State University
[email] Mazdak Arabi, Colorado State University, Fort Collins

Abstract: In this project we will develop a Geographic Information Systems (GIS) database for source-tracking of antibiotic resistance genes (ARG) as emerging contaminants in the South Platte and Cache la Poudre (Poudre) River watersheds in Colorado. ARG are the genetic elements that cause pathogenic bacteria to become resistant to antibiotics, rendering these drugs ineffective for fighting disease. ARG are also of interest because they are indicators of the impacts of another class of emerging contaminants, antibiotic pharmaceuticals, which have been demonstrated to be present in surface water and sediments in the Poudre and South Platte Rivers. The problem, thus, is that although ARG have also recently been documented in the Poudre River sediments, it is still not clear what the relative human and agricultural ARG inputs are. This results in a lack of appropriate guidance for combating the spread of antibiotic resistance. Therefore, the purpose of this study is to develop a GIS database for source-tracking human versus agricultural inputs of ARG and to develop a draft mitigation strategy for controlling the spread of ARG to drinking water sources. Specifically, the objectives will be to: O1- Develop a GIS database that documents ARG signatures with respect to other water quality attributes in the South Platte and Poudre watersheds; and O2- Analyze the data to identify spatial and temporal patterns of human and agricultural ARG inputs and to gain insight into potential best management practices (BMPs) that may address the issue. To achieve these objectives, we will use data on ARG signatures that we have collected for more than 2 years from key human and agriculturally impacted Poudre and S. Platte River sites as well as the wastewater treatment systems of representative dairies, beef feedlots, poultry farms and pork confined animal feeding operations (CAFOs) within the watersheds. The expected outcome is a better understanding of relative human and agricultural ARG inputs in the rivers. This information will be essential in developing draft BMPs for ARG control and will also provide insight into the overall impact of antibiotic pharmaceuticals and other pollutants. Thus, the outcome will represent a proactive approach to addressing the issue of emerging contaminants, and will place Colorado as a leader in helping solve an important world-wide human health problem.

Investigator(s):
[email] Stephanie Kampf, Colorado State University

Abstract: The Cache la Poudre River in northeastern Colorado is a source of water for many agricultural, municipal and industrial users. As in many Colorado River basins, both current and long-term water planning in the Cache la Poudre would benefit from a thorough characterization of the hydrologic regime. The proposed research will explore techniques for building a spatially explicit hydrologic model that can be used in flow forecasting on the Cache la Poudre. The first phase of the research will use stream gage measurements, weather and SNOTEL station measurements, and satellite-derived snow cover images to explore hydrologic response in the portion of basin upstream of the mouth of the Poudre Canyon. These measurements will be used to characterize historical patterns in precipitation and temperature and relate these patterns to flow contributions in different portions of the basin. The second phase of the research will use the hydrologic analyses to inform development of a new hydrologic model that uses station and satellite-derived precipitation and temperature data to predict the spring-summer hydrograph. This model will combine the predictive strength of statistical forecasting methods with a more complete representation of the spatial variability in flow generation processes throughout the basin. Unlike most current flow forecasting methods, which give only seasonal total flow volumes, the model developed will also produce a hydrograph showing the timing and quantity of predicted flow throughout the spring and summer. The model will be designed to have the capability for testing how different climate scenarios (precipitation and temperature distributions) could affect river flow in the upper Poudre Basin. The project as a whole represents a starting piece in a longer term research trajectory on the hydrologic regime throughout the Cache la Poudre basin, and elements of the study will be incorporated into undergraduate and graduate-level classes on watershed management and modeling. The hydrologic analyses will help determine which new climate and stream gauging station locations would best inform forecasting, and the model development will lead to enhanced flow forecasting methods that can incorporate spatial satellite data into flow predictions.

Investigator(s):
[email] Jeffrey D. Niemann, Colorado State University
[email] Timothy K. Gates, Colorado State University, Fort Collins
[email] Luis A. Garcia, Colorado State University, Fort Collins

Abstract: Irrigated agricultural systems in Colorado, and throughout the West, face increasing pressures to conserve water. The Lower Arkansas River Valley (LARV) is an excellent example of this situation. An expansive system of canals and reservoirs supplies water to more than 250,000 ac of irrigated land, which underpins the economy of southeastern Colorado. However, increasing water demands in Front Range communities have resulted in water transfers out of the valley, water rights litigation has placed increasingly strict conditions on maintaining return flows, and water quality issues are placing new constraints on water distribution and use. Either directly or indirectly, water conservation must be achieved by reducing non-beneficial consumptive use in the system, which means reducing evapotranspiration (ET) losses that occur from sources other than crops. These losses are expected to be significant because the water table, which provides a ready source of water for the ET process, is near the ground surface in much of the valley. In addition, uncropped areas represent roughly 50% of the valley during the growing season and a much larger portion during the rest of the year. Preliminary estimates suggest that tens of thousands of acre-feet are lost to non-beneficial ET from uncultivated areas each year, and a portion could be saved by lowering the water table. Much more work needs to be done to understand how non-beneficial ET depends on water table depth (DWT) and other factors such as vegetation and soil properties. This project aims to continue efforts to observe and quantify the relationship between ET and DWT for uncultivated areas in the LARV. Primary objectives for this second year of study are: (1) to clarify how vegetation and soil properties mediate the relationship between ET and DWT and (2) to characterize the sensitivity of ET to changes in DWT and other factors using a model. We will continue to monitor the two existing field sites and instrument a third site to increase the available data. ET will be estimated using remote sensing, and DWT will be measured using observation wells. Vegetation and soil characteristics will be quantified using a combination of field methods and remote sensing. Together, these observations will allow us to directly identify the role that DWT plays in determining ET losses from uncultivated lands under known soil and vegetation conditions. Ultimately, this research is expected to improve our understanding of the water budget in the LARV and to improve the numerical models that are being used to evaluate potential water conservation strategies.

Investigator(s):
[email] James Pritchett, Colorado State University

Abstract: Bioenergy crop production and refining are key opportunities for revitalizing rural communities in Colorado. This optimism stems, in part, from growing urban areas in Colorado that demand clean burning and relatively inexpensive biofuels. Yet, the same urban areas are rivals for two important inputs in biocrop farming: water and agricultural land. Increased municipal demands heighten the competition for water in Colorado's over-appropriated river basins increasing the value of each acre foot. Thus, the potential gains from bioenergy cropping must be attractive enough to retain water in irrigated agriculture else water will flow to municipal consumption. If profits for bioenergy crop production are limited, then outside investment in bioenergy refining and infrastructure is likely to suffer. The rural economic impacts of bioenergy cropping and increasing water resource demands stretch beyond the farm gate. Agribusinesses that rely on the sale of crop inputs (e.g., seed, chemical and fertilizer sales) and the use of farm products (e.g., ethanol plants, dairies, feedlots, sugar processors and meatpackers) will find their activities are substantially altered by bioenergy cropping and/or water transfers. If irrigated acres are permanently fallowed, input suppliers and agribusiness processors will face significant reductions in economic activity. As biocropping gains popularity, agribusinesses that compete with biorefining for farm products (diaries, feedlots, and sugar processing) will certainly need to adapt and perhaps relocate. The economic outcome is uncertain. Farming and agribusiness represent an important base industry for rural communities, and with few alternatives to agricultural production, these communities will suffer as economic activity is reduced. For the leaders of these communities, it is important to gain information about how resources, including tax revenues, may be altered by the competing incentives of water resources and bioenergy cropping. Likewise, water stakeholders, agribusiness leaders and farm organizations seek to understand the tradeoffs in policy initiatives. Can Colorado's agricultural producers meet the challenges of a burgeoning bioenergy industry while still supplying water to growing municipalities? What impacts will be felt by local agribusiness, both suppliers of inputs (e.g., local supply cooperatives) and those who rely on irrigated crops for their livelihood (e.g., sugar processors, dairies and feedlots)? This proposal's overall objective is to provide insights into these important questions. The research involves developing a computable general equilibrium model for the South Platte Basin. This economic model extends previous research regarding irrigated agriculture's contribution to rural economic activity. Yet, rather than a snapshot of the economy, the proposed model will trace flow of water resources in and out of the basin with water transfers, while suggesting how cropping patterns are altered with bioenergy adoption. Further, the proposed model focuses on the impact to agribusinesses that utilize and process farm products, an analysis that has been neglected. Proposal objectives also include plans for analyzing potential policy scenarios, dissemination of results and presentations to stakeholders.