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Sujay S Kaushal - One of the best experts on this subject based on the ideXlab platform.
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seeing the light urban Stream Restoration affects Stream metabolism and nitrate uptake via changes in canopy cover
Ecological Applications, 2019Co-Authors: Alexander J Reisinger, Sujay S Kaushal, Thomas R Doody, Peter M Groffman, Emma J RosiAbstract:: The continually increasing global population residing in urban landscapes impacts numerous ecosystem functions and services provided by urban Streams. Urban Stream Restoration is often employed to offset these impacts and conserve or enhance the various functions and services these Streams provide. Despite the assumption that "if you build it, [the function] will come," current understanding of the effects of urban Stream Restoration on Stream ecosystem functions are based on short term studies that may not capture variation in Restoration effectiveness over time. We quantified the impact of Stream Restoration on nutrient and energy dynamics of urban Streams by studying 10 urban Stream reaches (five restored, five unrestored) in the Baltimore, Maryland, USA, region over a two-year period. We measured gross primary production (GPP) and ecosystem respiration (ER) at the whole-Stream scale continuously throughout the study and nitrate (NO3- -N) spiraling rates seasonally (spring, summer, autumn) across all reaches. There was no significant Restoration effect on NO3- -N spiraling across reaches. However, there was a significant canopy cover effect on NO3- -N spiraling, and directly comparing paired sets of unrestored-restored reaches showed that Restoration does affect NO3- -N spiraling after accounting for other environmental variation. Furthermore, there was a change in GPP : ER seasonality, with restored and open-canopied reaches exhibiting higher GPP : ER during summer. The Restoration effect, though, appears contingent upon altered canopy cover, which is likely to be a temporary effect of Restoration and is a driver of multiple ecosystem services, e.g., habitat, riparian nutrient processing. Our results suggest that decision-making about Stream Restoration, including evaluations of nutrient benefits, clearly needs to consider spatial and temporal dynamics of canopy cover and trade-offs among multiple ecosystem services.
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Stream Restoration and sewers impact sources and fluxes of water carbon and nutrients in urban watersheds
Hydrology and Earth System Sciences, 2016Co-Authors: Michael J Pennino, Sujay S Kaushal, Paul M Mayer, Curtis A CooperAbstract:Abstract. An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and Stream Restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban Stream Restoration and sewer infrastructure. We compared an urban restored Stream with two urban degraded Streams draining varying levels of urban development and one Stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following Stream Restoration. Similarly, we found that the restored Stream showed significantly lower (p
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Stream Restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds
Hydrology and Earth System Sciences Discussions, 2015Co-Authors: Michael J Pennino, Sujay S Kaushal, Paul M Mayer, Curtis A CooperAbstract:Abstract. An improved understanding of sources and timing of water and nutrient fluxes associated with urban Stream Restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in Stream Restoration and sanitary infrastructure. We compared a restored Stream with 3 unrestored Streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following Stream Restoration. Similarly, we found that the restored Stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d−1) compared with two urban unrestored Streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d−1) draining higher impervious surface cover. Peak runoff in the restored Stream was more similar to a less developed Stream draining extensive stormwater management (13.2 ± 1.9 mm d−1). Interestingly, the restored Stream exported most carbon, nitrogen, and phosphorus loads at relatively lower Streamflow than the 2 more urban Streams, which exported most of their loads at higher and less frequent Streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha−1 yr−1), total nitrogen (4.5 ± 0.3 kg ha−1 yr−1), and total phosphorus (161 ± 15 g ha−1 yr−1) were significantly lower in the restored Stream compared to both urban unrestored Streams (p < 0.05) and similar to the Stream draining stormwater management. Although Stream Restoration appeared to potentially influence hydrology to some degree, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the restored Stream was derived from leaky sanitary sewers (during baseflow), similar to the unrestored Streams. Longitudinal synoptic surveys of water and nitrate isotopes along all 4 watersheds suggested the importance of urban groundwater contamination from leaky piped infrastructure. Urban groundwater contamination was also suggested by additional tracer measurements including fluoride (added to drinking water) and iodide (contained in dietary salt). Our results suggest that integrating Stream Restoration with Restoration of aging sanitary infrastructure can be critical to more effectively minimize watershed nutrient export. Given that both Stream Restoration and sanitary pipe repairs both involve extensive channel manipulation, they can be considered simultaneously in management strategies. In addition, ground water can be a major source of nutrient fluxes in urban watersheds, which has been less considered compared with upland sources and storm drains. Goundwater sources, fluxes, and flowpath should also be targeted in efforts to improve Stream Restoration strategies and prioritize hydrologic "hot spots" along watersheds where Stream Restoration is most likely to succeed.
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effects of Stream Restoration on denitrification in an urbanizing watershed
Ecological Applications, 2008Co-Authors: Sujay S Kaushal, Paul M Mayer, Peter M Groffman, Elise A Striz, Arthur J GoldAbstract:Increased delivery of nitrogen due to urbanization and Stream ecosystem degradation is contributing to eutrophication in coastal regions of the eastern United States. We tested whether geomorphic Restoration involving hydrologic ''reconnection'' of a Stream to its floodplain could increase rates of denitrification at the riparian-zone-Stream interface of an urban Stream in Baltimore, Maryland. Rates of denitrification measured using in situ 15 N tracer additions were spatially variable across sites and years and ranged from undetectable to .200 l gN � (kg sediment) � 1 � d � 1 . Mean rates of denitrification were significantly greater in the restored reach of the Stream at 77.4 6 12.6 l gNkg � 1 � d � 1 (mean 6 SE) as compared to the unrestored reach at 34.8 6 8.0 l gNkg � 1 � d � 1 . Concentrations of nitrate-N in groundwater and Stream water in the restored reach were also significantly lower than in the unrestored reach, but this may have also been associated with differences in sources and hydrologic flow paths. Riparian areas with low, hydrologically ''connected'' Streambanks designed to promote flooding and dissipation of erosive force for storm water management had substantially higher rates of denitrification than restored high ''nonconnected'' banks and both unrestored low and high banks. Coupled measurements of hyporheic groundwater flow and in situ denitrification rates indicated that up to 1.16 mg NO3 � -N could be removed per liter of groundwater flow through one cubic meter of sediment at the riparian-zone-Stream interface over a mean residence time of 4.97 d in the unrestored reach, and estimates of mass removal of nitrate-N in the restored reach were also considerable. Mass removal of nitrate-N appeared to be strongly influenced by hydrologic residence time in unrestored and restored reaches. Our results suggest that Stream Restoration designed to ''reconnect'' Stream channels with floodplains can increase denitrification rates, that there can be substantial variability in the efficacy of Stream Restoration designs, and that more work is necessary to elucidate which designs can be effective in conjunction with watershed strategies to reduce nitrate-N sources to Streams.
Peggy A. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Defining a Standard of Care for Urban Stream Restoration Projects
Journal of Professional Issues in Engineering Education and Practice, 2014Co-Authors: Peggy A. JohnsonAbstract:AbstractDesign engineers are expected to meet an accepted standard of care, which provides assurance that reasonable care and quality of service have been performed by the professional. Although this expectation exists for engineers in the design of urban Stream Restoration projects, no guidelines currently exist that provide the design engineer with a reasonable set of expectations. In this paper, a guideline for a standard of care appropriate to urban Stream Restoration projects is developed based on skills and knowledge needed by the design engineer that have been identified in prior studies. Communication between the design engineer and the funding and permitting agencies is critical to agree upon and acknowledge the standard of care expectations prior to a project start.
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Applying Cost-Based Risk Assessment to Stream Restoration Design
World Environmental and Water Resources Congress 2007, 2007Co-Authors: Sue L. Niezgoda, Peggy A. Johnson, Louise O. SlateAbstract:A low-risk, Stream Restoration design includes methods that validate design assumptions, incorporate uncertainty in the decision-making process during the project design phase, and reduce uncertainty by checking the final design. A twostep method of incorporating uncertainty and risk in Stream Restoration design has been developed as a combination of Design Failure Modes and Effects Analysis (DFMEA) and risk quantification. As a first step, DFMEA is applied to identify risk in terms of ratings with respect to consequence of failure, the likelihood of occurrence of a failure, and the ability to detect a failure. Due to its evolutionary nature, the DFMEA can be revised to account for design modifications and relative ratings are re-evaluated to examine reductions in uncertainty, and thereby, risk. The second step of the method is quantifying risk using initial and expected failure costs. Expected failure cost is defined as the product of probability of failure and the cost associated with failure. Since failure probability and cost of failure are both difficult to determine directly in Stream Restoration, the consequence and likelihood of occurrence ratings from the DFMEA can be used to estimate the expected cost and probability of failure, respectively. Using this method, risk can be estimated for several Restoration design alternatives and compared to provide justification and guidance on selecting the most cost effective design alternative. The two-step, riskbased method is illustrated through application to a Stream relocation project in Pennsylvania and a Stream Restoration project in North Carolina. Overall, the twostep method presented here can prove valuable in decision-making and will improve the likelihood of success in Stream Restoration design.
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Improving the Urban Stream Restoration Effort: Identifying Critical Form and Processes Relationships
Environmental Management, 2005Co-Authors: Sue L. Niezgoda, Peggy A. JohnsonAbstract:Stream Restoration projects are often based on morphological form or Stream type and, as a result, there needs to be a clear tie established between form and function of the Stream. An examination of the literature identifies numerous relationships in naturally forming Streams that link morphologic form and Stream processes. Urban Stream Restoration designs often work around infrastructure and incorporate bank stabilization and grade control structures. Because of these imposed constraints and highly altered hydrologic and sediment discharge regimens, the design of urban channel projects is rather unclear. In this paper, we examine the state of the art in relationships between form and processes, the strengths and weaknesses of these existing relationships, and the current lack of understanding in applying these relationships in the urban environment. In particular, we identify relationships that are critical to urban Stream Restoration projects and provide recommendations for future research into how this information can be used to improve urban Stream Restoration design. It is also suggested that improving the success of urban Restoration projects requires further investigation into incorporating process-based methodologies, which can potentially reduce ambiguity in the design and the necessity of using an abundant amount of in-Stream structures.
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Stream Restoration in the vicinity of bridges
Journal of The American Water Resources Association, 2002Co-Authors: Peggy A. Johnson, Eric R Brown, David L RosgenAbstract:ABSTRACT: The number of Stream Restoration and enhancement projects being implemented is rapidly increasing. At road crossings, a transition must be created from the restored channel through the bridge or culvert opening. Given conflicting design objectives for a naturalized channel and a bridge opening, guidance is needed in the design of the transition. In this paper we describe the use of vanes, cross vanes, and w-weirs, commonly used in Stream Restoration and enhancement projects, that may provide an adequate transition at bridges. Laboratory experiments were conducted on vanes and cross vanes to provide a transition for single span bridge abutments and on w-weirs to provide a transition for double span bridges which have a pier in mid-channel. The results of the experiments provided design criteria for transitions using each of the three structures. Prior field experience provided guidance on appropriate applications in terms of the Stream and bridge characteristics.
Sue L. Niezgoda - One of the best experts on this subject based on the ideXlab platform.
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defining a Stream Restoration body of knowledge as a basis for national certification
Journal of Hydraulic Engineering, 2014Co-Authors: Sue L. Niezgoda, Peter Richard Wilcock, Daniel W. Baker, Jennifer Mueller, Janine M CastroAbstract:DOI: 10.1061/(ASCE)HY.1943-7900.0000814IntroductionThe practice of Stream Restoration has become widely accepted asan essential component to improving ecosystem function andenhancing aquatic biodiversity (Wohl et al. 2005). Despite theabundance of projects being implemented, a lack of definitivetrainingrequirements,designprocedures,andmonitoringprotocolsremain for the practice of Stream Restoration. Given the lack ofconsistency, many Restoration projects end in frustration, excessivecosts, and poor results (e.g., Williams et al. 1995; Kondolf 1998;Johnson and Brown 2001; Roni et al. 2002; Wohl et al. 2005;Bernhardt et al. 2007; Roni et al. 2008). The fact that methodand experience are both varied and even poorly defined in anew and emerging profession is not surprising; however, the com-bination of diverse and inconsistent training and methodologymakes progress in transforming the practice of Stream Restorationinto a mature profession difficult. The widespread practice of re-storation, now a billion dollar a year industry in the United States(Bernhardt et al. 2005), coupled with highly inconsistent results,demands its conversion into a profession with broadly acceptedprinciples and methods of tested reliability.As a profession advances, it must have ways to assess andassure the adequacy of education and training curricula and thecompetency of individual professionals (Ford and Gibbs 1996;Pomeroy-Huff et al. 2009). At the core of the process of maturinga profession is the establishment of a body of knowledge (BOK), adocument generated by experts to identify and delineate theconcepts, facts, and skills that practitioners in that profession areexpected to master (Morris et al. 2006; Pomeroy-Huff et al.2009). For example, project management professionals saw a clearneed to formulate a common and consistent set of core competen-cies on which they could base a project management certificationand advance their emerging profession (Morris et al. 2006; Winteret al. 2006). In the emerging profession of Stream Restoration, asimilar call exists for the establishment of consistent training stan-dards, standards of practice, and professional certification, drivenlargely by the lack of agreed on criteria for judging Restoration suc-cess and highly inconsistent project results (Palmer et al. 2005;Marr 2009; Kite 2009; Fischenich 2009). The development of aprofession with standards of practice and/or certification first re-quires establishment of a training and education structure that pro-vides consistency and can support and incorporate advances inunderstanding (Morris et al. 2006).A fully effective symbiosis among research, training, andpractice has yet to emerge in Stream Restoration; however, severalattemptsweremadeduringthepast10yearstoestablishthecurrentandfutureneedsinStreamRestoration educationandtraining [RiverRestoration Northwest (RRNW) 2003; (AFS Curriculum WorkingGroup, unpublished data, 2003); P. Wilcock, unpublished internalreport, December 2006 RRNW, in cooperation with Oregon StateUniversity and Portland State University, sought to advance thequality of the river Restoration practice by identifying Restorationeducational needs (RRNW 2003). In 2003, RRNWand its partnersimplemented a survey to assess the job tasks, educational back-grounds, and training needs of professionals working on river re-storation projects in the northwestern United States and Canada.The key results are as follows.1. Available training is multidisciplinary with most universityand short courses focused on ecology, fluvial geomorphology,fisheries, Restoration, and soils. Fisheries biologists and civilengineershavethegreatestrangeoftrainingacrossdisciplines.2. Improved skills and competence in fluvial geomorphology,field techniques, Restoration techniques, and biology/ecologywere identified as important for a practicing professional.
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A cost-based risk assessment method for selecting Stream Restoration design alternatives
2013Co-Authors: Sue L. NiezgodaAbstract:A low-risk, Stream Restoration design includes methods that validate design assumptions, incorporate uncertainty in the decision-making process during the project design phase, and reduce uncertainty by checking the final design. A two-step method of incorporating uncertainty and risk in Stream Restoration design has been developed as a combination of Design Failure Modes and Effects Analysis (DFMEA) and risk quantification. As a first step, DFMEA is applied to identify risk in terms of ratings with respect to consequence of failure, the likelihood of occurrence of a failure, and the ability to detect a failure. Due to its evolutionary nature, the DFMEA can be revised to account for design modifications and relative ratings are re-evaluated to examine reductions in uncertainty, and thereby, risk. The second step of the method is quantifying risk using initial and expected failure costs. Expected failure cost is defined as the product of probability of failure and the cost associated with failure. Since failure probability and cost of failure are both difficult to determine directly in Stream Restoration, the consequence and likelihood of occurrence ratings from the DFMEA can be used to estimate the expected cost and probability of failure, respectively. Using this method, risk can be estimated for several Restoration design alternatives and compared to provide justification and guidance on selecting the most cost effective design alternative. The two-step, risk-based method is illustrated through application to a Stream relocation project in Pennsylvania. Overall, the two- step method presented here can prove valuable in decision-making and will improve the likelihood of success in Stream Restoration design.
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Developing Probability of Failure Estimates for Stream Restoration Design Components
World Environmental and Water Resources Congress 2009, 2009Co-Authors: Timothy M. Sliwinski, Sue L. Niezgoda, Michael DevasherAbstract:Stream Restoration projects are proliferating in all regions of the country to provide improvements to Streams disturbed by highway construction, urbanization, and channel modifications. The morphologically-based natural channel design method is commonly used to design Stream Restoration projects; however, the design approach is often vague, qualitative, and lacking in guidance. This can lead to an increase in project uncertainty and costs. A two-step method of incorporating uncertainty and risk in Stream Restoration design has been developed as a combination of Design Failure Modes and Effects Analysis (DFMEA) and risk quantification. The purpose of DFMEA is to prioritize failures in accordance with their risk. The definition of risk contains two components: (1) probability of failure and (2) consequence of failure. Probability of failure of Stream Restoration design components is often difficult to determine due to lack of published failure data. In the existing risk assessment method, the likelihood of occurrence ratings from the DFMEA are used to estimate the probability of failure. A set of tasks were carried out to improve the application of the two-step risk assessment method by developing better estimates of probability of failure for Stream Restoration design components. A literature review was performed to compile potential failure modes, causes of failure, associated predictor variables, and uncertainty in the predictor variables for Stream Restoration design components. Following this, advanced probabilistic techniques, namely Logistic Regression Analysis (LRA) and Monte Carlo Simulation (MCS), were applied to develop improved failure probabilities for Stream Restoration design. MCS was used to incorporate the results of the literature review and to select values for the predictor variables for use in the LRA. The LRA provided a model that was used for prediction of the probability of occurrence of an event. The results were incorporated into the existing risk assessment method to create a better decision making tool for Stream Restoration design. The incorporation of the resulting risk assessment method in the design phase of Stream Restoration projects can be important to decision making and will improve the likelihood of success.
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Applying Cost-Based Risk Assessment to Stream Restoration Design
World Environmental and Water Resources Congress 2007, 2007Co-Authors: Sue L. Niezgoda, Peggy A. Johnson, Louise O. SlateAbstract:A low-risk, Stream Restoration design includes methods that validate design assumptions, incorporate uncertainty in the decision-making process during the project design phase, and reduce uncertainty by checking the final design. A twostep method of incorporating uncertainty and risk in Stream Restoration design has been developed as a combination of Design Failure Modes and Effects Analysis (DFMEA) and risk quantification. As a first step, DFMEA is applied to identify risk in terms of ratings with respect to consequence of failure, the likelihood of occurrence of a failure, and the ability to detect a failure. Due to its evolutionary nature, the DFMEA can be revised to account for design modifications and relative ratings are re-evaluated to examine reductions in uncertainty, and thereby, risk. The second step of the method is quantifying risk using initial and expected failure costs. Expected failure cost is defined as the product of probability of failure and the cost associated with failure. Since failure probability and cost of failure are both difficult to determine directly in Stream Restoration, the consequence and likelihood of occurrence ratings from the DFMEA can be used to estimate the expected cost and probability of failure, respectively. Using this method, risk can be estimated for several Restoration design alternatives and compared to provide justification and guidance on selecting the most cost effective design alternative. The two-step, riskbased method is illustrated through application to a Stream relocation project in Pennsylvania and a Stream Restoration project in North Carolina. Overall, the twostep method presented here can prove valuable in decision-making and will improve the likelihood of success in Stream Restoration design.
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Urban Stream Restoration: Guidance for Monitoring and Assessment Protocols
World Environmental and Water Resource Congress 2006, 2006Co-Authors: John S. Schwartz, Sue L. Niezgoda, Louise O. Slate, Robert Prager, Donald D. Carpenter, Munsell Mcphillips, Shannon LucasAbstract:Stream Restoration over the past decade has become big business, with annual expenditures in the billions of dollars. Many projects have been completed in urban watersheds because of changing hydrology and sediment budgets have resulted in excessive bank erosion that threatens urban infrastructure. Though many projects have been completed nationally, post-project monitoring and assessments are not routinely conducted. If assessments are conducted, they are rarely reported in publicly accessible documents. Professionals involved in Stream Restoration have expressed the need for greater monitoring and assessment of projects, particularly in urbanizing watersheds where undisturbed reference Streams are not common. The Urban Streams Committee of the Urban Water Resources Research Council and the River Restoration Committee jointly formed a task committee with the goal of producing a guidance document for monitoring and assessment of urban Stream Restoration projects. This paper summarizes the progress to date of the committee.
Curtis A Cooper - One of the best experts on this subject based on the ideXlab platform.
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Stream Restoration and sewers impact sources and fluxes of water carbon and nutrients in urban watersheds
Hydrology and Earth System Sciences, 2016Co-Authors: Michael J Pennino, Sujay S Kaushal, Paul M Mayer, Curtis A CooperAbstract:Abstract. An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and Stream Restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban Stream Restoration and sewer infrastructure. We compared an urban restored Stream with two urban degraded Streams draining varying levels of urban development and one Stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following Stream Restoration. Similarly, we found that the restored Stream showed significantly lower (p
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Stream Restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds
Hydrology and Earth System Sciences Discussions, 2015Co-Authors: Michael J Pennino, Sujay S Kaushal, Paul M Mayer, Curtis A CooperAbstract:Abstract. An improved understanding of sources and timing of water and nutrient fluxes associated with urban Stream Restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in Stream Restoration and sanitary infrastructure. We compared a restored Stream with 3 unrestored Streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following Stream Restoration. Similarly, we found that the restored Stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d−1) compared with two urban unrestored Streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d−1) draining higher impervious surface cover. Peak runoff in the restored Stream was more similar to a less developed Stream draining extensive stormwater management (13.2 ± 1.9 mm d−1). Interestingly, the restored Stream exported most carbon, nitrogen, and phosphorus loads at relatively lower Streamflow than the 2 more urban Streams, which exported most of their loads at higher and less frequent Streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha−1 yr−1), total nitrogen (4.5 ± 0.3 kg ha−1 yr−1), and total phosphorus (161 ± 15 g ha−1 yr−1) were significantly lower in the restored Stream compared to both urban unrestored Streams (p < 0.05) and similar to the Stream draining stormwater management. Although Stream Restoration appeared to potentially influence hydrology to some degree, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the restored Stream was derived from leaky sanitary sewers (during baseflow), similar to the unrestored Streams. Longitudinal synoptic surveys of water and nitrate isotopes along all 4 watersheds suggested the importance of urban groundwater contamination from leaky piped infrastructure. Urban groundwater contamination was also suggested by additional tracer measurements including fluoride (added to drinking water) and iodide (contained in dietary salt). Our results suggest that integrating Stream Restoration with Restoration of aging sanitary infrastructure can be critical to more effectively minimize watershed nutrient export. Given that both Stream Restoration and sanitary pipe repairs both involve extensive channel manipulation, they can be considered simultaneously in management strategies. In addition, ground water can be a major source of nutrient fluxes in urban watersheds, which has been less considered compared with upland sources and storm drains. Goundwater sources, fluxes, and flowpath should also be targeted in efforts to improve Stream Restoration strategies and prioritize hydrologic "hot spots" along watersheds where Stream Restoration is most likely to succeed.
Margaret A Palmer - One of the best experts on this subject based on the ideXlab platform.
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assessing Stream Restoration effectiveness at reducing nitrogen export to downStream waters
Ecological Applications, 2011Co-Authors: Solange Filoso, Margaret A PalmerAbstract:The degradation of headwater Streams is common in urbanized coastal areas, and the role these Streams play in contributing to downStream pollution is a concern among natural resource managers and policy makers. Thus, many urban Stream Restoration efforts are increasingly focused on reducing the downStream flux of pollutants. In regions that suffer from coastal eutrophication, it is unclear whether Stream Restoration does in fact reduce nitrogen (N) flux to downStream waters and, if so, by how much and at what cost. In this paper, we evaluate whether Stream Restoration implemented to improve water quality of urban and suburban Streams in the Chesapeake Bay region, USA, is effective at reducing the export of N in Stream flow to downStream waters. We assessed the effectiveness of restored Streams positioned in the upland vs. lowland regions of Coastal Plain watershed during both average and stormflow conditions. We found that, during periods of low discharge, lowland Streams that receive minor N inputs from ...
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Stream Restoration strategies for reducing river nitrogen loads
Frontiers in Ecology and the Environment, 2008Co-Authors: Laura S Craig, Martin W Doyle, Brian P Bledsoe, Emily S Bernhardt, Solange Filoso, Margaret A Palmer, Peter M Groffman, David C Richardson, Brooke A HassettAbstract:Despite decades of work on implementing best management practices to reduce the movement of excess nitrogen (N) to aquatic ecosystems, the amount of N in Streams and rivers remains high in many watersheds. Stream Restoration has become increasingly popular, yet efforts to quantify N-removal benefits are only just beginning. Natural resource managers are asking scientists to provide advice for reducing the downStream flux of N. Here, we propose a framework for prioritizing Restoration sites that involves identifying where potential N loads are large due to sizeable sources and efficient delivery to Streams, and when the majority of N is exported. Small Streams (1st–3rd order) with considerable loads delivered during low to moderate flows offer the greatest opportunities for N removal. We suggest approaches that increase in-Stream carbon availability, contact between the water and benthos, and connections between Streams and adjacent terrestrial environments. Because of uncertainties concerning the magnitud...
