The studies in this dissertation address the issue of variability in runoff generation and pollutant concentration in urban areas, and specifically in the catchments of stormwater control measures. There is an imperfect correlation between runoff volumes and the capture area and land uses of urban catchments. Variable capture areas and uncertainty in urban runoff sources complicate stormwater control measure design and urban stream assessment. Four stormwater control measures in upstream suburban Philadelphia, ranging in capture area from 0.11 ha to 32 ha, were monitored, sampled, and modeled. Sampling was conducted in the watersheds of Wissahickon Creek, Tookany Creek, and Pennypack Creek. The approaches discussed below have the goal of better understanding runoff and the movement of associated contaminants into stormwater retention basins and streams. Rather than viewing runoff generation and contaminant transport as a static process, this work proposes that the amount of runoff contributed from different areas of a catchment changes during and between storm events, and that the origin and concentration of contaminants change as a result. Linking source areas to runoff volumes through natural and modeled tracers could improve predictions of water quality and quantity in stormwater control measures in urban streams. Nitrate (NO3–) isotope ratios were used as tracer of flow from different urban land uses. Time series samples of stormwater runoff entering two stormwater control measures (a constructed wetland and a small bioretention basin) were collected and analyzed to distinguish sources of NO3– by samples’ δ15N and δ18O ratios. A Bayesian mixing model was used to determine that NO3– sources were a mix of soil nitrogen (N) and atmospheric deposition across six storm events. Furthermore, atmospheric versus soil N sources varied throughout the storms. The large catchment of the constructed wetland had more NO3– source variability between samples compared to the small catchment of the bioretention basin. Thus, the NO3– isotopes suggest more distinct flow paths in the large catchment and more mixing of flow across land uses in the small catchment. Quantifying flow path variability from storm to storm and between different catchments can improve design and placement of urban stormwater control measures. A distributed hydrologic model, GSSHA, was used to simulate overland runoff from impervious and semi-pervious land covers in the catchment of a stormwater control measure. The positions of low vegetation and impervious land uses over the catchment were rearranged to create hypothetical catchments during four storm events. Fluctuating source proportions over time suggested that grab samples might not be adequate for capturing average overland runoff chemistry. It was also found that the portion of total runoff volume from impervious areas varied from 50 to 75% while the relative proportion of impervious cover remained constant at 54%. Land use percentages averaged over capture areas are frequently used to estimate runoff amounts and pollutant concentrations, but this model disrupts the assumption that urban hydrologic responses can be predicted from imperviousness alone. Overland runoff was measured and modeled before and after the installation of two stormwater control measures, a berm and a bioswale. Discharge in the stream was modeled for 9 storms ranging in size from 14 to 54 mm. We found that during 4 of the modeled storms there was no decrease in stream discharge and decreases in discharge were generally only observed for low intensity storms. Furthermore, only 5% of the stream catchment was captured by SCMs. Modeled tracers, used to track runoff contributions from areas upslope of the SCMs found that the size of upslope contributing areas did not predict the proportion of runoff generated in each area. Field data to support the models included water level loggers and samples of overland runoff collected in subsurface stormwater casing. After the SCMs were installed, less water was captured in downslope sampling bottles, but new flow paths developed. Furthermore, significant variation was observed in upslope concentrations of dissolved nutrients and total suspended solids, casting doubt on whether point samples of urban overland runoff geochemistry can be representative given variable runoff generation and heterogeneous land uses. This study points out the challenges in evaluating stormwater control measures and reveals that source areas’ contribution to stream flow varies independently of their size. Therefore, modeling before stormwater control measure installation is recommended to determine the factors that influence a capture area’s contribution to urban streamflow. / Geoscience

No description available.

No description available.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Lee R. Skabelund / Stormwater management is typically approached from different perspectives by practicing professionals. As such, stormwater planning/design is not always completed as a multi-disciplinary coalition of experts using holistic and synergistic methods. For a number of years, engineers and design professionals, particularly landscape architects, have been employing various strategies and techniques to address on-site stormwater management in terms of water quality and quantity. There is increasing awareness that in order to create solutions that are effective over both the short and long-term a landscape architect’s approach needs to account for the health, safety and welfare perspectives carried by engineers, the unique aspects of particular project sites, their surroundings and bio-regional context, as well as the perceptions of clients, other key stakeholders, and the broader public. This research investigates the various criteria integral to developing an analytic framework for ecologically-appropriate stormwater planning/design (Sustainable Stormwater Evaluation and Site Assessment or SSWESA). SSWESA is proposed as a type of decision-tree for site analysis of sustainable systems pertaining to stormwater. Using the SSWESA process is expected to help researchers and professionals make better planning and design decisions as they select and implement appropriate best management practices (BMPs) for a given site and context. My intent in developing SSWESA is to help designers assess existing and potential stormwater functions at the site scale in order to promote sustainable planning and design based upon the important principle: “First, do no harm”. It is also my intent to promote further research related to sustainability by providing references and sources from experts in the various fields related to ecologically-based stormwater management. A review of the literature related to ecological factors relevant to low impact stormwater management assisted in the development and refinement of the criteria for stormwater assessment and evaluation. In this report, the SSWESA framework is tested on a public school property in Manhattan, Kansas to demonstrate how the framework is applied and to understand the questions and issues that arise from its use.

Understanding the extent to which human activities impact surface water resources has become increasingly important as both human population growth and related landscape changes impact water quality and quantity across varying geographical scales. Skypark, Santa’s Village is a 233.76-acre tourism-based outdoor recreation area located in Skyforest, California residing within the San Bernardino National Forest. The park is situated at Hooks Creek, the headwaters of the Mojave River Watershed, and is characterized by a diverse landscape that includes forest cover and human development, including impervious surfaces, a restored meadow, and recreational trails. In 2016, Hencks Meadow was considered degraded by human activity and restored by the Natural Resources Conservation Services (NRCS) using best management practices (BMPs) to manage stormwater runoff and mitigate pollutants entering recreational downstream surface water. Three BMP detention basins were constructed to store and improve water quality from stormwater runoff. The purpose of this study is to observe the extent to which the engineered BMP detention basins design were effective in mitigating stormwater pollution from entering Hooks Creek. Over a six to eight month period (January to August), ponds were tested in situ bi-weekly for temperature (ºC), dissolved oxygen (mg/L), pH, turbidity (NTU), conductivity (µS/cm), nitrate (mg/L), and ammonium (mg/L), with additional laboratory tests for total suspended solids (mg/L), total dissolved solids (mg/L), chemical oxygen demand (mg/L), total coliform (MPN/100mL), Escherichia coli (MPN/100mL), and trace metals (µg/L). The results of this study support that the BMP design is improving surface stormwater runoff from impervious surfaces before it enters Hooks Creek. Findings could also promote the design and implementation of stormwater BMP detention basins at other site locations where water degradation is evident. Furthermore, this research can be used to promote the necessary improvement of water quality and quantity on a widespread geographical scale.

L’objectif de ce travail est d’évaluer le transfert des métaux lourds au sein d’une installation de traitement des eaux de ruissellement routier et de développer un procédé épuratoire qui permettrait de parfaire le traitement de ces eaux. La démarche scientifique déployée a d’abord consisté en la caractérisation des flux métalliques acheminés dans un bassin de rétention recevant des eaux de ruissellement provenant d’une autoroute et en l’évaluation du transfert de cette pollution métallique vers la végétation environnante. Les résultats de cette première étude ont permis de mettre en évidence : (1) un transfert des métaux lourds (Cd, Ni, Zn) des compartiments eau – sol vers les macrophytes aquatiques présent sur le site, (2) la capacité de ces macrophytes à accumuler des polluants métalliques au sein de leurs tissus et (3) le caractère bioindicateur de ces macrophytes pour assurer une surveillance de la pollution métallique présente dans les eaux de ruissellement. Compte tenu de la capacité des plantes à accumuler des métaux, en particulier au niveau de leurs racines, un procédé de phytoremediation appelé marais flottant a été proposé pour affiner le traitement des eaux de ruissellement. Les performances épuratoires de ces systèmes ont été évaluées en microcosmes et la faisabilité technique de pouvoir implanter de tels systèmes directement à la surface d’ouvrages existants a également été appréhendée. Les résultats ont démontré que les marais flottants peuvent tout à fait être mis en œuvre à la surface de bassins de rétention sous réserve que les matériaux choisis pour la construction de ces systèmes soient adaptés aux conditions environnementales. Les résultats ont également mis en évidence la capacité des marais flottants à éliminer les métaux présents en phase aqueuse ainsi que l’importance du réseau racinaire qui se développe dans la colonne d’eau sur la rétention des polluants et la filtration des particules fines en suspension. Enfin, cette étude a démontré que les marais flottants peuvent être considérés comme des systèmes de traitement pérennes et nécessitant très peu de maintenance. / The objective of this work is to evaluate the heavy metal transfer into an urban stormwater treatment device and to develop a treatment process which would allow improving the treatment of these waters. The scientific approach consisted first to characterize the metal loads forwarded into a retention pond receiving stormwater runoff coming from a highway and to evaluate the transfer of this metal pollution to the surrounding vegetation. The results of this preliminary study demonstrated: (1) a heavy metal transfer (Cd, Ni and Zn) from the water and soil compartments to the aquatic macrophytes present on the studied site, (2) the capacity of these macrophytes to accumulate metal pollutants into their tissues and (3) the bioindicator value of these macrophytes for biomonitoring of stormwater metal pollution. Regarding the capacity of plants to accumulate metals, especially in their roots, a phytoremediation process called floating treatment wetlands was proposed to improve urban stormwater quality. The treatment performances of these systems were evaluated through a microcosm experiment and the technical feasibility for implanting such floating systems directly on the surface of existing ponds was also evaluated. The results showed that floating treatment wetlands can be operated on the surface of retention pond provided that the material chosen for the construction of these systems are well adapted to environmental conditions. The results also brought to light the efficiency of floating treatment wetlands for metal uptake from water as well as the importance of the root system on pollutant retention and the filtration of fine suspended particles. Finally, this study showed that floating treatment wetlands can be considered as sustainable treatment systems that need low maintenance.

Nonpoint source pollution captured by urban stormwater runoff is the greatest challenge for surface water quality improvements. Computer-based design tools have been developed to help mediate this issue by guiding end users through the implementation of decentralized stormwater management. The majority of these tools focus on treatment via biofiltration, yet concern regarding this treatment regime is rising. Case studies from research past clearly indicate the susceptibility of groundwater to contamination from extensive anthropogenic activity at the surface. Contaminants, such as nitrates and pathogens, are not completely removed before runoff enters the underground watercourse. Additionally, national and state legislation, which explicitly lists where neglect for groundwater quality is permissible—exacerbate concerns. This research analyzes the efficiency the BMP Siting Tool developed by the US Environmental Protection Agency and the Grey-to-Green Decision Support Tool developed by the University of South Florida. The tools were used to obtain cartographic data illustrating suitable sites for bioswales and infiltration basins throughout northern portion of Hillsborough County, Florida. This data was then integrated with the Karst Aquifer Vulnerability Index (KAVI) groundwater vulnerability model. The area of bioswales and infiltration basins that intersected areas of the KAVI model listed as ‘highly vulnerable’ or ‘moderate-to-highly vulnerable’ was calculated. This permitted an assessment of which BMP facility had the greatest sitings atop vulnerable areas, respective of the tool. The BMP Siting Tool sited 2.80% of all bioswales and 27.89% of all infiltration basins above vulnerable areas. Likewise, the Grey-to-Green Decision Support Tool sited 21.66% of all bioswales and 9.62% of all infiltration basins above vulnerable areas. These results prompted the development of a supplemental groundwater vulnerability framework to be incorporated into both tools’ analytical process.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The City Hall of Santa Maria hired the Municipal Plan of Environmental Sanitation of Santa Maria (MPLAENS), in relation to the urban drainage, one of the themes of the Plan. The Ministry of Cities encourages the use of urban drainage practices that include as much approaches with compensatory techniques, as approaches with principle of urban development of low impact. Thus, this research aimed to identify if the (MPLAENS) incorporates proposals focused in the control of drainage in the source and how they are adressed. The study was performed in three steps: initially, it was carried out the analysis of measures of control of the storm water runoff proposed in (MPLAENS), in order to understand in which level were received the precepts of measures of control of the storm water runoff at source (MCS). Afterwards, the feasibility of MCS for the city has been verified, considering the restrictions of each device and the particularities of the urban occupation and the hydrologic group of the soil. To provide subsidy for the future sizing of MCS, it was necessary an intermediate step of determination of hydrologic parameters of sizing, such as, update of the relation intensityduration- frequency (IDF), determination of value of the specific flow of predevelopment (Qpd) and the volume of control (v). Based on definitions of control of the drainage at source, it is possible to affirm that, none of the proposals of MPLAENS for the urban drainage meet the precepts of measures of control at source. From the held observations in this study and the data available, it is possible to state that large extent of the urban perimeter of the city has potential for the use of MCS. The suggestions presented in MPLAENS in relation to drainage consist in the construction of approximately 631 km of drainage networks, besides the construction of approximately 180.000 m³ of anti-DSP deposit, being these distributed within the next twenty years of project of the Plan. For an estimate of deployment of the micro drainage network, the authors of MPLAENS adopted the flow of 6,9 m³.s-1, calculated by the rational method with the use of the following parameters: Runoff coefficient (R) = 0,6; Basin area (B) = 1,5 km²; Time of concentration (tc) = rain duration (t) = 1,63 hours; Time of return (Tr) = 10 years; Intensity of the rain (I) = 27,4 mm.h-1. To obtain the referent value of the intensity of the rain (I), the authors used the Gumbel distribution of the data recorded by Instituto Nacional de Meteorologia (National Institute of Meteorology). The IDF equation updated in this study and the same values of (t) and (Tr) used in MPLAENS, results in a value of (I) = 42,72 mm.h-1 for this intensity, and for the same values of (R) and (B) the result is a flow of 10,69 m³.s-1, value 56 percent higher than the present in MPLAENS. The potential of the municipality for the deployment of MCS became evident through the results of this study, thus, the use of drainage practices in small-scale spread over the whole river basin in order to reproduce or maintain the hydrological conditions of predevelopment presents itself as a positive alternative. / A Prefeitura de Santa Maria contratou o Plano Municipal de Saneamento Ambiental de Santa Maria (PLAMSAB), em relação à drenagem urbana, uma das temáticas do Plano, o Ministério das Cidades estimula a utilização de práticas de drenagem urbana que incluem tanto as abordagens com técnicas compensatórias, quanto as abordagens com princípio do desenvolvimento urbano de baixo impacto. Assim, esta pesquisa teve como objetivo identificar se o (PLAMSAB) incorpora propostas voltadas para o controle do escoamento na fonte e de que forma elas são abordadas, o estudo foi conduzido em 3 etapas. Inicialmente foi realizada a análise das medidas de controle do escoamento pluvial propostas no (PLAMSAB), estudando em que nível são atendidos os preceitos de medidas de controle do escoamento pluvial junto à fonte (MCF). Posteriormente foi verificada a viabilidade das MCF para o município, considerando as restrições de cada dispositivo e as particularidades da ocupação urbana e do grupo hidrológico do solo. Para fornecer subsídio para o dimensionamento futuro das MCF, foi necessário uma etapa intermediaria de determinação de parâmetros hidrológicos de dimensionamento, tais como, atualização da relação intensidade-duração-frequência (IDF), determinação do valor da vazão específica de pré-desenvolvimento (Qpd) e do volume de controle (v). Baseado nas definições de controle da drenagem na fonte, é possível afirmar que nenhuma das propostas do PLAMSAB para a drenagem urbana, atende aos preceitos de medidas de controle na fonte, a partir das observações realizadas neste estudo é possível afirmar, a partir dos dados disponíveis, que grande parte do perímetro urbano do município tem potencial para a utilização de MCF. As propostas apresentadas no PLAMSAB, em relação a drenagem, consistem na construção de aproximadamente 631 km de redes de drenagem, além da construção de aproximadamente 180.000 m³ de depósito anti-DSP, sendo essas distribuídas na cobertura dos 20 anos do horizonte de projeto do Plano. Para a previsão de implantação da rede de microdrenagem, os autores do PLAMSAB adotaram a vazão de 6,9 m³.s-1, calculado mediante o método racional, com a utilização dos seguintes parâmetros: Coeficiente de escoamento (C) = 0,6; Área da bacia (A) = 1,5 km²; Tempo de concentração (tc) = duração da chuva (t) = 1,63 horas; Tempo de retorno (Tr) = 10 anos; Intensidade de chuva (I) = 27,4 mm.h-1, para a obtenção do valor referente à intensidade de chuva (I), os autores utilizaram o ajuste de extremo Gumbel dos dados registrados pelo INMET (Instituto Nacional de Meteorologia). Utilizando a equação IDF atualizada neste estudo, e considerando os mesmos valores de (t) e (Tr) utilizados no PLAMSAB, resulta um valor de (I) = 42,72 mm.h-1, para esta intensidade, e para os mesmos valores de (C) e (A), resulta uma vazão de 10,69 m³.s-1, valor 56% maior que a apresentada no PLAMSAB. A potencialidade do município para implantação de MCF ficou evidenciada a partir dos resultados deste estudo, o uso de práticas de drenagem em pequena escala, disseminados por toda a bacia hidrográfica a fim de reproduzir ou manter as condições hidrológicas de pré-desenvolvimento se apresenta como uma alternativa positiva.

No description available.

Cities within California are beginning to incorporate urban agriculture into their land use designations. Prompted by residents and local organizations, cities are hoping to capture the benefits that urban agriculture provides. Research has shown that urban agriculture renews and beautifies neighborhoods, provides healthy food choices, increases public health, has the potential to help with stormwater runoff, creates jobs, and fosters community. In the last few years, several California cities have made headlines as they have adopted new zoning codes that include urban agriculture. In reviewing these new zoning codes and exploring the topic of urban agriculture, it became evident that just because an urban farm was small, organic and provided certain benefits that it was not free from impacting its surroundings. As more urban agricultural ventures are established within cities, planners have to carefully consider their effect. One such impact could be stormwater pollution. There is insufficient research to determine whether there is a relationship between urban agriculture and stormwater, however, studies on conventional agriculture and urban landscaping (mainly urban lawns) show that each of these areas pollute the local water bodies with sediment, chemicals, and nutrients. Is urban agriculture different? This thesis utilizes two case studies within California, the City of Oakland and the City of San Diego, to examine the similarities and differences between each city’s urban agriculture ordinances and evaluate whether or not the cities have adjusted stormwater requirements in parallel with these ordinances. Interview responses and site visits in each city were analyzed and compared to expound upon the approaches each city engaged. Using the collected data and analysis as a base, a set of guidelines was created for managing stormwater runoff from urban agriculture.