Grantee Research Project Results
Components of Riverbed Filtration Enhancement in Urban Stream Restoration SitesEPA Grant Number: FP917375
Title: Components of Riverbed Filtration Enhancement in Urban Stream Restoration Sites
Investigators: Robinson, Jesse D
Institution: The State University of New York
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2011 through August 31, 2013
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2011) RFA Text | Recipients Lists
Research Category: Fellowship - Water Quality: Hydrogeology and Surface Water , Academic Fellowships
Due to the extensive and serious nature of impairment in many urban streams, successful aquatic restoration projects remain a challenge. However, physical alterations to streams resulting from restoration activities may be capable of enhancing hydraulic drivers of riverbed filtration, potentially improving important stream functions. This study will explore relationships between transient storage modeling and stream channel characteristics to identify trends in hyporheic exchange, a driver of riverbed filtration, through examining urban and non-urban degraded, reference condition and restored sites.
Approach:Demonstration of improved stream function is important for determining successful aquatic restoration. Direct measurement of these functions, such as nutrient processing, often is complicated by data intensive methods, site heterogeneity and temporal variations in environmental factors. Transient storage modeling (TSM) may represent one method for achieving rapid assessment of indicators of improved stream function. TSM utilizes a mass balance approach to following a conservative tracer into sub-surface storage zones within streams, and can provide information about exchange rates and the residence time of water moving through these zones. TSM measurements provide information about the physical drivers of exchange and the characteristics of the streambed, which are known to relate to other important stream functions.
Transient storage modeling has been used in a variety of landscapes, and is under exploration in a network of degraded, reference condition and restored sites. Post-processing analysis of the conservative tracer signal provides information about sub-surface storage zones, but other processes, such as surface detention areas, must be carefully isolated. Appropriate characterization of stream parameters at each site is crucial to developing scaling relationships between model output and drivers of exchange. Despite complexities, physical enhancement through use of structures in restoration sites has been proven to alter hydraulic drivers of riverbed filtration. Due to these enhancements, differentiation between the transient storage signal in degraded, reference condition and restored sites is anticipated. The degree of differentiation in this signal, and predictive power of direct measurements of stream characteristics, will provide evidence for the success of both the methods proposed and urban stream restoration in general.
Potential to Further Environmental / Human Health Protection
The impairment seen in urban streams reduces the ability of these ecosystems to provide important functions, from support of aquatic life at the base of the food chain, to the removal of pollutants from surface waters. This state of impairment also has the effect of reducing recreational and quality of life benefits in areas where people are most likely to live. For citizens in these areas, developing strategies to repair these ecosystems requires that they begin with a complete understanding of the state of efforts in urban environments to date.