Browsing by Subject "Stormwater management"

Now showing 1 - 6 of 6
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    ItemOpen Access
    A Cost-Benefit Analysis of Rainwater Harvesting
    (2008-04-24T23:31:40Z) Hicks, William D
    Rainwater harvesting has provided a water source for communities around the world dating back to circa 1500 B.C. This ancient technology continues to serve populations today, mainly in poor, rural or dry regions of the world and island communities. Contemporary green building and stormwater management programs (e.g., Leadership in Energy and Environmental Design – LEED, Low Impact Development – LID, Better Site Design) suggest that rainwater harvesting can serve as a valuable stormwater management tool even in areas where municipal water supplies are readily available. Regardless, private developers are most apt to incorporate these systems into commercial development designs if the benefits justify the costs. Analyses of local rainfall data and predicted potential water usage at commercial facilities in Arlington County, Virginia reveal that rainwater harvesting systems conserve potable water, protect surface water quality and minimize flood risk. However, economic analyses from the perspective of a private developer using two case studies of commercial developments in Arlington suggest that the benefits of incorporating rainwater harvesting into building designs do not justify the cost of implementing this technique. Notwithstanding, results from a sensitivity analysis indicate that charging tenants a modest price premium of one percent or less for the privilege of occupying a “green” building yields a positive return to investing in rainwater harvesting.
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    ItemOpen Access
    Impacts of green infrastructure implementation within the Neuse River Basin
    (2015-04-24) Green, Benjamin
    American Rivers is advocating for implementation of Green Infrastructure (GI) as a stormwater management strategy within the City of Raleigh. Incorporation of GI into future development plans is an appealing option for growing urban centers to minimize their impact upon surrounding aquatic ecosystems. Since Raleigh lies outside the regulatory boundary of the Falls Lake Nutrient Strategy, there is not a significant driver in place to encourage a shift towards GI. This study provided American Rivers with estimates of potential scale of GI retrofit implementation within a highly developed stormwater drainage basin, as well as the benefits those retrofits would provide in terms of nutrient load and peak flow reductions from stormwater flow. This was accomplished through the development of a GIS tool that identifies potential GI retrofit locations within Raleigh stormwater drainage basins, expediting the retrofit field reconnaissance process. The outputs of this tool were then incorporated into PLOAD, a GIS-based pollutant load modeling application for watershed-scale management, which provided estimates of mass loading rates of TN, TP, and TSS. The study area consisted of 11 subcatchments within Pigeon House Branch stormwater drainage basin (3200 acres, ~32% mean impervious coverage). Estimated annual pollutant load reductions resulting from GI implementation were 0.67, 9.92, and 16.82 tons of TP, TN, and TSS, respectively, although the accuracy of these numbers is questionable due to the coarse scale at which PLOAD operates. Ideally, other modeling efforts can be applied within this study’s framework to produce more informed scenarios within other drainage basins throughout the Neuse River Basin.
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    ItemOpen Access
    Innovative Financing for Green Stormwater Infrastructure: Lessons Learned from Energy Efficiency
    (2016-04-29) Starkman, Kendall
    Stormwater management can be a significant challenge in urban areas. As population density grows and impervious surface cover increases, the amount and intensity of stormwater runoff escalates correspondingly, placing added stress on water management systems and natural ecosystems. Green stormwater infrastructure (GSI) is increasingly being seen as a critical tool for addressing these challenges (Garrison and Hobbs 2011). Although a number of cities across the country have turned to GSI as a key component of their stormwater management system, oftentimes the scope is limited to public property. Since GSI is a distributed approach to stormwater management, programs must engage private property owners (Francis 2010). Energy efficiency programs have seen significant success engaging private property owners across the built environment despite experiencing many of the same challenges attracting investment in the face of high up-front costs and limited inherent collateral value (Palmer, Walls and Gerarden 2012). This project aims to better explain the key factors that influence the success of three types of energy efficiency financing programs in the United States and draw cross-sector parallels to GSI in order to inform a decision-making framework for GSI program design. This is accomplished through 1) a review of the existing literature on energy efficiency program design and the potential equivalencies between energy efficiency and green stormwater infrastructure, 2) an exploration of three financing mechanism case studies, and 3) the definition of decision criteria to provide initial direction for the evaluation of appropriate financing mechanisms in a specific case. In order to better understand the settings in which specific energy efficiency financing mechanisms would be most appropriate, this research evaluated three financing mechanisms: on-bill repayment, PACE financing, and performance contracting with Energy Services Companies (ESCOs). The data informing these case studies was gathered through research of secondary sources, a series of interviews of energy efficiency program administrators and energy and/or GSI industry experts, and a review of example programs. The case analysis informed a consideration of how each financing mechanism could be applied in the stormwater context. The findings reach beyond the existing literature to examine national level themes and provide a local-level decision making framework. Based on the findings of this report, a number of key factors exist that can direct decision-making around green stormwater infrastructure financing. First, a fundamental consideration is whether a stormwater fee structure exists to create the opportunity for savings. Assuming this requirement is met, the following criteria indicate the suitability of the three financing mechanisms for a specific jurisdiction: building stock of greatest concern, authorizing legislation, political buy-in, incentives, and regulatory requirements. The importance of each criteria varies for each financing mechanism. PACE programs are most appropriate in states with a history of PACE authorizing legislation, strong regulatory drivers for action and a wider range of target property sizes. Performance contracting is more appropriate in places with a high concentration of large-scale commercial building stock, limited legislative support and multiple available incentives. On-bill repayment programs are most applicable where there are more opportunities to pursue small-scale GSI and strong regulatory drivers for action. In addition, shared key factors that apply to all three of the case financing mechanisms will impact program viability and are important to consider in program design. These include the stormwater fee size and available margin, the potential to offer credit enhancements, the ability to leverage an economy of scale, the policy requirements affecting loan term stringency, and existing availability of financial partners. An applied analysis of how these findings impact Seattle, WA further illustrates the implications of these findings. The City has an itemized stormwater fee structure, an existing stormwater consent order and is actively investing in GSI. PACE financing is not possible in the state due to legislative restrictions. However, a stormwater credit already exists in the city and a commercial GSI program would target medium to large-scale commercial customers. Therefore, it is recommended that the City of Seattle explore performance contracting by supporting the development of a GISC. In order to make this possible, the City could create a public private partnership with local innovators and consider opportunities to provide credit enhancements. Secondarily, the City might also consider the potential to offer on-bill repayment for small scale projects. In both cases, the City will need to conduct further inquiry into the financial implications and political feasibility of these endeavors and create a framework for measurement and verification of stormwater savings.
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    Study of Land Use Impacts and Options for Innovative Stormwater Management in a Rapidly Changing Watershed: Richland Creek, Wake County, North Carolina
    (2023-04) Fischer, Atalie; Sheldon, Jessica; Jacob, Natasha; Jing, Yikai
    The Blue Ridge Corridor (BRC) in northwest Raleigh, NC is currently being redeveloped through a partnership between the Blue Ridge Corridor Alliance (BCRA) and the City of Raleigh. However, the scope of this development is unprecedented within the region and larger watershed of Richland Creek. Rapid urbanization can degrade water quality and functionality of these ecosystems. Our team’s goal is to provide a baseline for water quality and quantity in the watershed, assess land cover changes, develop a stormwater case study, and create a green stormwater framework that would provide guidance and opportunity for ecologically minded development. We analyzed and modeled recent and projected future land use and land cover change. Development in the Richland Creek Watershed has increased by 9.22% in the past 22 years, and an additional 24% of the watershed will become urbanized in the next 20 years, largely at the expense of forested land. Accelerating urban land pressures will require well-designed development to maintain water quality and ecosystem health. The results of our water quality and quantity assessment reveal signatures of increased urban land covers in Richland and Crabtree Creeks. Although rainfall has been constant, stream flow has increased, a change that can be attributed to runoff from increased impervious surface. Additionally, we see increased total hardness attributable to the weathering of asphalt, and increased turbidity attributable to the rapid transport of urban runoff. Improved monitoring of Richland and Crabtree Creek will help assessment of the watershed under increasing development. We modeled replacement of impervious surface cover (ISC) with pervious surfaces to determine how runoff could be reduced in current and future development. Decreasing ISC for three points of interest (POI) had varying effects, but overall decreased peak flows in all storm events. Development should focus on areas where a change in land cover does not greatly impact peak flows and avoid hydrologically sensitive areas. We identified relevant examples of green stormwater infrastructure that could be implemented in the corridor, outlined their benefits, and identified possible funding programs for their construction and maintenance. A public StoryMap was a step in the final synthesis of the project, which was to create a framework for ecologically minded development in the BRC. Our ArcGIS online StoryMap provides context of the project, overview of methods, results, and recommendations. Environmental and economic success of the Blue Ridge Corridor development will be more likely if engaged stakeholders possess a shared understanding of the development and how green infrastructure and low-impact design can reduce environmental costs and maximize environmental benefits throughout the project. This framework is achievable through the implementation of the following recommendations: (1) Maximize the use of green stormwater infrastructure throughout the BRC; (2) Regular monitoring of Richland Creek through placement of USGS gage; and, (3) Inform and engage stakeholders through creation of a publicly available StoryMap. These three steps address the findings, limitations, and next steps identified in the project. Incorporation of the framework into the BRC development plans is critical to the ecosystem health and resilience of the Richland Creek watershed.
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    ItemOpen Access
    The Emerging Importance of Stormwater Management with a Focus on the City of Philadelphia
    (2012-04-18) Erickson-Ludwig, Alistar
    Over 80 percent of the population of the United States lives in cities. The large population coupled with a dense built environment means that cities are generally at a higher risk for the negative consequences of polluted water. Philadelphia is a dense urban city with two major waterways flowing through it. As a city with a large population and large percentage of developed land, flood control and water quality are two major issues facing the City. In 2006, the Philadelphia Water Department passed a regulation requiring new development and redevelopment projects to manage stormwater runoff. An assessment was completed to understand why particular stormwater management practices were chosen in various private development projects throughout Philadelphia and learn the positives and negatives of managing them.
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    Working towards environmental restoration through small scale engagement in coastal North Carolina
    (2011-04-29) Rootes-Murdy, Kirby
    Nonpoint source (NPS) pollution is a pervasive problem throughout the United States. In coastal North Carolina, NPS most commonly takes the form of stormwater carrying large quantities of bacteria into neighboring estuarine waterways. Elevated levels of bacteria can have significant effects on water quality and result in area closures for commercial shellfish harvesting. This masters project investigates stormwater retrofitting potential in a small coastal neighborhood located within the White Oak River watershed. Applying Geographical Information Systems (GIS) to estimate impervious surface and model stormwater runoff, a mixed method approach is used to better evaluate areas of concern within a subwatershed of the White Oak River. In analyzing both state-level stormwater management guidelines and interviewing local residents on their perceptions of water quality, a goal of this study is to determine what considerations are needed to guide current and future stormwater projects. The results of this study indicate that the current stormwater regulatory framework operates on a temporal scale that hinders comprehensive funding, implementation, and monitoring of Best Management Practices (BMP) retrofitting projects. Modifications on the subwatershed level highlight impervious surface coverage from development may be significantly increasing sheet stormwater runoff. Qualitative findings demonstrate the educational outreach could be useful in gaining community support for future BMP projects. Further research in applying participatory mixed methods to study local stormwater may provide greater stakeholder engagement and successful implementation of low-cost BMPs in continuing efforts of water quality improvement.