The overall goal of this project is to determine the watershed-scale impacts of water storage systems on water quality and quantity in Porter Bayou Watershed, Mississippi. We plan to test our central hypothesis and accomplish the goal of the project by pursuing the following objectives: <OL> <LI> Determine the downstream nitrogen and phosphorous concentrations of effluent from water storage systems (Research Objective);<LI> Quantify the effects of water storage systems on downstream flow levels through a watershed (Research Objective);<LI> Increase the adoption of on-site water storage technology and dissemination of potential benefits (Extension Objective); <LI> Enhance the science education of middle and high school students by promoting the benefits of water conservation and environmental stewardship (Education Objective). </ol> Our expected outcomes include determination of the level of nutrient reduction that can be achieved by using a water storage system, determination of changes in streamflow patterns caused by the presence of water storage systems in the watershed, farmers and landowners who are better informed of the water quality and quantity benefits of using on-site storage systems, and students who are trained and educated in the area of water quality.
Non-Technical Summary: <BR>Farmers and landowners are faced with two major issues with regard to sustainably managing agroecosystems in the Mississippi Delta region, namely, the declining groundwater levels in the Mississippi Delta Shallow Alluvial Aquifer, and nutrient loads into the Mississippi River and the Gulf of Mexico. The declining groundwater levels in the Mississippi Delta are representative of conditions in the mid-South. On-site water storage reservoirs offer farmers and landowners the flexibility of providing irrigation water and capturing nutrient-rich tailwater from irrigated fields. Collecting and reusing tailwater benefits the environment by avoiding discharge of nutrients into surface waters. Farmers are currently installing these systems, and requests for assistance through NRCS have increased in the past year. The placement of these systems throughout a watershed can be better targeted if we can quantify the downstream nutrient reduction and water quantity effects of the technology. Once we have a better understanding of how these systems affect downstream water quality and quantity, we can also use watershed runoff models to target implementation of these practices in critical areas throughout the mid-South. <P> Approach: <BR> For Objective 1, we will install SIRCO automatic vacuum samplers to collect water samples at four sites throughout the headwater area of Porter Bayou Watershed, including one near an existing water storage system. Collection of water samples from all four locations will be done every two weeks from April to October. The samplers will be programmed to collect a sample every hour for 24 hours. In addition, we will collect samples from in-stream sites when runoff from a rainfall event or excess irrigation causes the water in the ditch to overflow into the stream. Water samples will be analyzed for pH, turbidity, total suspended solids, total nitrogen, total phosphorus, and orthophosphate. Water level sensors will be deployed in the tailwater recovery ditch to measure the depth of water over time. Time series water level data will provide information on the changes in water depth as a result of precipitation, evaporation, surface runoff, and irrigation events. A weather station will be installed to measure precipitation, temperature, relative humidity, solar radiation, and other weather variables. In order to accomplish Objective 2, we will analyze the streamflow records from four USGS gauges within the watershed to determine a) if there are any differences in streamflow before and after system installation, and b) if there are cumulative effects on downstream volume as the number of water storage systems in operation increases. We will also concurrently analyze the aforementioned streamflow data with precipitation data to determine if the source of the flow is from rainfall runoff or irrigation runoff. Essential to the completion of Objective 3, is the support of various stakeholder groups. We plan to conduct meetings and field days in the Mississippi Delta Region. We will provide farmers information about the current state of technology, including management options, regarding the on-site storage system, and elicit input from stakeholders. Finally, as part of Objective 4, we will provide hands-on water resource training in Porter Bayou and campus-based mentoring for Grade 6-12 students.