Water Resources Research Act Program

Details for Project ID 2016AL176B

Identification of Stream Bed Sediment Sources Using Sediment Fingerprinting

Institute: Alabama
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $22,000 Total Non-Federal Funds: $43,742

Principal Investigators: Jasmeet Lamba

Abstract: Excessive delivery of sediment to surface waters results in increased turbidity, reduced light penetration and transport of sediment-bound nutrients, such as phosphorus (P) to surface waters. Excessive transport of P to streams causes eutrophication of rivers, streams and lakes decreasing their recreational values. In US, about 24% of streams are impaired because of sediment and P (USEPA, 2014a). In Alabama (AL), sediment and P account for impairment of about 28% of streams (USEPA, 2014b). In addition to sediment-bound nutrients, excessive levels of metals bound to in-stream sediment severely affect aquatic organisms (Giddings et al., 2001). Furthermore, Escherichia coli pathogen can survive much longer in streams with excessive amount of sediment (Jamieson et al., 2005). Therefore, reducing sediment delivery to streams will help to decrease levels of metals, P and Escherichia coli in streams. Implementation of best management practices (BMPs) helps to reduce excessive delivery of sediment and sediment-bound contaminants to streams and thereby improve water quality. Since the promulgation of the Clean Water Act in 1972, reducing non-point source (NPS) pollution through the implementation of BMPs has received considerable attention. However, in the past four decades, numerous NPS watershed projects have reported little or no improvement in water quality following BMP implementation (Meals et al., 2010; Jarvie et al., 2013; Sharpley et al., 2013). A detailed understanding of sediment and sediment-bound P sources and transport from uplands to streams is needed to target BMPs. To effectively target and implement appropriate BMPs, the provenance of sediment must be known. In AL, previous studies have indicated that stream banks or upland areas are important sources of sediment (e.g., Niruala et al., 2013 and Simpson et al., 2014). However, few studies have been done to determine relative importance of each source (uplands versus stream banks) within a watershed. Establishing relative importance of each sediment source will help to target BMPs at the most important sediment sources within a watershed. Additionally, in challenging economic times, as funding levels for sediment-control BMPs are likely to decline, there is a need for targeted BMP approach. Targeted implementation of BMPs would enable effective use of federal and state funds to alleviate NPS pollution issues. Watershed scale models (e.g., SWAT (Soil and Water Assessment Tool; Neitsch et al., 2011)) have been commonly used to identify areas contributing disproportionate amount of pollutants (e.g., sediment and phosphorus) to streams. However, there are several limitations associated with the models to represent complex hydrological processes within a watershed. For example, SWAT model does not adequately simulate complex processes of stream bank erosion (Neitsch et al., 2011), which can be one of the dominant source of sediment within a watershed. Sediment fingerprinting techniques have been successfully used to identify sources of in-stream sediment. These techniques involve identification of potential sediment sources and allocating the amount of sediment contributed by each source through the use of natural tracers and a combination of field data collection, laboratory analysis, and statistical modeling techniques. Identification of in-stream sediment sources using natural tracers will improve our understanding of linkages between uplands and in-stream sediment processes (e.g., stream bank erosion) within a watershed and will have implications for a wide range of water quality problems.