There is a growing need to manage water resources in a sustainable way, particularly in semi arid areas, with dramatic social and economic development as well as rapid population growth. Optimising water allocation in a river basin is an important aspect ensuring equitable and efficient water use. This research develops an optimisation approach (the Integrated Water Resource Optimisation model, IWRO) to optimise the conjunctive use of surface water and groundwater resources in a sustainable manner. The IWRO model is comprised of a surface water optimisation model (SWO) and the Tsinghua groundwater optimisation (TGO) model. These models employ Genetic Algorithms (GAs) to optimise water allocation. Application of a surface water optimisation (SWO) model incorporating a GA is demonstrated initially for a simple test case, through which the GA approach was validated against known solutions. Sensitivity analysis of different operators and parameters related to GAs was also carried out. The validated SWO model was then applied to a more complex system, the Shiyang River Basin in Gansu Province in China, to maximise equitable surface water supplies. On the groundwater side, the GA approach was applied with the existing Tsinghua groundwater model to optimise groundwater supplies with sustainability considerations. The results were compared with those from an existing model (the WEAP model), indicating that the IWRO model is capable of satisfying the objectives of equitable water allocation and groundwater sustainability set for it. In the context of Integrated Water Resources Management (IWRM), account must be taken of a wide range of social and environmental issues. Different scenarios were therefore designed for the Shiyang River Basin management. Various criteria in terms of economic, social, environment and water security were also indentified for further multi-criterion decision making analysis.

The demand-driven and participatory approach to water resource development and management in Tanzania has been both praised and criticized; some see progress where others see increased inequalities. This study focuses on one progressive, demand-driven NGO which has a participatory approach to water resource development and management. This NGO, MSABI, is active in Kilombero Valley in southern Tanzania, and can be considered successful as it manages to keep 91 % of its water points functional, whilst the national average for pump functionality is just above 50 %. To study the performance of MSABI from a user perspective, it was decided that two sites in Kilombero Valley should be investigated in terms of users’ views on water access and quality. The identification of sites is based on population density and landcover change, so that the issues of scale and urban bias, as well as changes in the landscape affecting hydrological processes, are accounted for. In total, 29 interviews were conducted (October to November 2014), 15 at the Ifakara study site, the more densely populated location, and 14 at the Mchombe Ward study site. The interviews were semi-structured, using a participatory approach, focusing on users’ perspectives on water sources and the access to and quality of those water sources in dry and rainy seasons. The information gathered was used to construct definitions for water access and quality. These definitions, as well as the two locations and categorization of participants according to socio-economic status, were then used to sort and analyse the collected material. The results show that MSABI does not manage to make water accessible in an equitable way because of its demand-driven and participatory approach to water resource development and management. However, MSABI offers the only improved water source at the Mchombe Ward study site, except for one improved open well. MSABI manages to counter urban-bias better than any of the other water resource development and management facilitators encountered at the two study sites. The seasons influence water access, especially at the more peripheral locations, where improved water sources are less common and, as open water sources, are more prone to drought and contamination. When participants in Ifakara seasonally migrate for farming, during 4-5 months per year, the majority’s access to improved water sources is lost. At the distant seasonal fields, open water sources are more common and few report that they treat the unsafe water. The migration to peripheral farmlands coincides with the rainy season, causing open water sources to have their lowest water quality when seasonal migrants utilize them. This underlines the importance of securing safe water supply for people at remote locations, and the important role MSABI plays as water resource developer at those locations. In conclusion, if the current demand-driven and participatory approach to water resource development and management is to be retained, regardless of the heavy criticism it has received with regards to equity, this study suggests that the practices of MSABI should be spread further based on MSABI’s ability to increase safe water access at remote locations. Another recommendation is to further look into the effects of seasonal migration on access to safe water. The effect seasonal migration has on water access in Kilombero could exist in other areas in Tanzania or in other countries. The aspect of seasonal migration might show that water access statistics are misleading, as the seasonal water consumption in remote locations risks being omitted in official statistics.

Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These increased loads can contribute to impairment of streams in developed areas and ultimately to Lake Champlain. In this study we selected six watersheds that represent a range of road types (gravel and paved) and road densities (rural, suburban, and urban) present in Chittenden County, one of the most developed areas in Vermont. The location and density of road networks were characterized and quantified for each watershed using GIS analysis. Monitoring stations in each watershed were constructed and instrumented to measure discharge and water quality parameters continuously from spring through early winter. Storm event composite samples and monthly water chemistry grab samples were collected and analyzed for total nitrogen, total phosphorus, chloride, and total suspended sediments. Results from this study show that road type and road density are closely linked with the level of impairment in each watershed. Total phosphorus and total nitrogen from storm event composite samples and monthly grab samples significantly increased along a gradient of increasing road network density. Chloride concentrations increased several orders of magnitude along this same gradient. With the exception of Alder Brook where total suspended sediment (TSS) concentrations tended to be high, there were no significant differences in TSS concentrations between rural and developed watersheds. The elevated storm event TSS concentrations in the rural streams suggest that the unpaved roads in the rural watersheds contribute to stormwater runoff loads and that sediment control, at least in the developed watersheds, might be fairly effective. The overall results from this study show that local roads are a significant source of impairment for streams in the Chittenden County area. Most of these roads are municipal roads that are not under management of the Vermont Agency of Transportation. Thus, local actions will be necessary to reduce runoff and pollutant loading from these roads.

Despite decades of U.S. water quality management efforts, over half of assessed waterbody units were threatened or impaired for designated uses in the most recent assessments, with urban runoff being a leading contributor to those impairments. This cumulative research explores several aspects of urban runoff dynamics through a combination of field study and modeling. Stormwater ponds are ubiquitous in developed landscapes due to their ability to provide multiple forms of treatment for stormwater runoff. However, evolving design goals have reduced the applicability of much of the early work that was done on pond effectiveness. In this study, we instrumented a recently constructed detention pond in Burlington, VT, USA. Flow gaging demonstrated that the pond achieved a 93% reduction in event peak flow rates over the monitoring period. Storm sampling showed that the pond significantly reduced total (TN) (1.45 mg/L median influent, 0.93 mg/L median effluent, p < 0.001) and total phosphorus (TP) (0.498 mg/L median influent, 0.106 mg/L median effluent, p < 0.001) concentrations over the events sampled. A loading analysis estimated the TN and TP removal efficiencies for the pond to be 23% and 77% respectively. Lastly, temperature data collected from the pond showed that during the summer the pond accumulates considerable heat energy. This study adds to the body of literature on detention pond performance, and raises concerns about the extensive use of stormwater ponds in watersheds where thermal stress is a concern. EPA SWMM is a widely used urban hydrologic, hydraulic and water quality model, though its application can be limited due to its deterministic nature, high dimensional parameter space, and the resulting implications for modelling uncertainty. In this work, I applied a global sensitivity analysis (SA) and evolutionary strategies (ES) calibration to SWMM to produce model predictions that account for parameter uncertainty in a headwater tributary case study in South Burlington, VT, USA. Parameter sensitivity was found to differ based on model structure, and the ES approach was generally successful at calibrating selected parameters, although less so as the number of concurrently varying parameters increased. A watershed water quality analysis using the calibrated model suggested that for different events in the record, the stream channel was alternately a source and a sink for sediment and nutrients, based on the predicted washoff loads and the measured loads from the stream sampling stations. These results add to the previous work on SWMM SA, auto-calibration, and parameter uncertainty assessment. Lastly, given the extent of eutrophication impairment in the U.S., I compared TN and TP data collected in these original works with national and regional datasets. TN concentrations sampled in this work were generally commensurate with values reported elsewhere, however TP data were not. Drainage area attributes and an event based rainfall runoff analysis of the study catchments provided circumstantial support for the idea that runoff from lawns is driving the high TP loads in Englesby Brook. The role of pet wastes is considered as a potentially fruitful area for further research.

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or sink for greenhouse gas emissions. This research examines the design, construction, and development of monitoring methods for bioretention research, using the University of Vermont (UVM) Bioretention Laboratory as a case study. In addition, this research evaluates mobilization patterns and pollutant loads from road surfaces during the "first flush" of runoff, or the earlier part of a storm event. Finally, this research analyzes the comparative pollutant removal performance of bioretention systems on a treatment by treatment basis. At the UVM Bioretention Laboratory, eight lined bioretention cells were constructed with monitoring infrastructure installed at the entrance and at the subterranean effluent. A conventional, sand and compost based, bioretention soil media was compared to a proprietary media engineered to remove phosphorus, called Sorbtive Media™, under simulated increases in precipitation. Two drought tolerant vegetation mixes, native to the northeast, were compared for sediment and nutrient retention. Each treatment was sampled for soil gas emissions to determine if it was a source or a sink. The monitoring infrastructure designs used in this research allowed for the effective characterization of pollutant mass loads entering and exiting bioretention. Cumulative mass loads from stormwater were found to be highest for total suspended solids, followed by total Kjeldahl nitrogen, nitrate, non-labile phosphorus and soluble reactive phosphorus, in descending order by mass. Total suspended solids, total Kjeldahl nitrogen, and non-labile phosphorus mass were well retained by all bioretention treatments. However, the compost amendment in the conventional soil media was found to release labile nitrogen and phosphorus, far surpassing the mass loads in stormwater. When compared with conventional media, Sorbtive Media™ was highly effective at removing labile phosphorus and was also found to enhance nitrate removal. Systems containing deep-rooted vegetation (Panicum virgatum) were found to be particularly effective at retaining both labile and non-labile constituents. Overall, none of the bioretention treatments were found to be a significant source of N2O and were small sinks for CH4 in most treatments.

The effective management of non-point source nutrient pollution continues to prove elusive. Though the scientific literature is unequivocal that all anthropogenic land uses contribute to non-point source (NPS) pollution, variable levels of contribution over time and across location and complex relationships between cost and effect make finding technologically effective management solutions difficult. In addition, these solutions are implemented in a world of scarce resources, diverse and often competing concerns and values, and intense public scrutiny. Clearly, making the best possible decision about how to manage NPS pollution under these conditions is not simple. My overarching goal was to develop and test several practical approaches that provide insight into the implications of management decisions and the trade-offs facing water quality managers using the challenges of restoring Lake Champlain as a test case. I first demonstrate a simple spreadsheet-based method for (1) identifying the areas of greatest potential for further phosphorus reductions, (2) estimating the potential scale of those reductions, and (3) identifying the severe tradeoffs that exist between cost and effectiveness at high levels of management. Results of this method suggest that better and more extensive management of developed impervious surfaces and annual cropland and hayland represent the greatest potential for phosphorus reductions. Farmstead management, combined sewer overflows, and wastewater treatment present little opportunity under the current regulatory environment. Results also suggest that due to order-of-magnitude differences in cost-effectiveness between management practices for developed and agricultural lands, substantial tradeoffs exist between cost-efficiency and equity in the distribution of responsibility for management. Second, in an effort to quantify the variability of NPS contributions over time and space, I developed and applied a Bayesian hierarchical modeling approach to incorporate annual hydrologic variability and uncertainty about land use areas into estimates of land-use specific phosphorus loading rates and watershed-scale residual loading. The model was able to replicate both average load and the variability around that average with an acceptable degree of precision. The results of this approach suggest that for some watersheds, unmanageable sources of phosphorus are dominant. Third, I applied a Bayes network to predict the effects of alternative management scenarios on phosphorus loads. Using evolutionary optimization and a multiple-criteria decision analysis, I explored the tradeoffs between cost, effectiveness, and distributional equity in the burden of management. Results of this study indicate that the probability that phosphorus loads will comply with regulatory targets is, in some watersheds, small under any management scenario. More interestingly, it also appears that there are large differences between watersheds in the ability of management actions to raise those probabilities, and the significant and non-linear tradeoffs between cost, effectiveness, and equity will make decision-making - and achieving restoration targets - difficult. Together, these approaches provide a foundation for a fuller and more completely informed decision-making process that incorporates uncertainty and identifies key trade-offs for the State of Vermont as it implements a new management plan for Lake Champlain.

Lake Champlain is a major economic driver for Vermont's tourism economy, as well as a primary source of drinking water for many of the state's residents but nutrient pollution represents a potential threat to ecosystem health and economic well-being. From December 2011 to December 2012 a field trial of an EAF steel slag filter was assessed for its feasibility in treating wastewater originating from Swan Valley Cheese (SVC), in Swanton, VT. The study focuses on a period of the filter's operation from May 4 to October 10, 2012. The plant generates approximately 20,000 gallons per day of high P concentration wash water which is treated in an open aerated lagoon. The filter treated effluent from this lagoon. The major goals of this research were to conduct a field trial of an EAF steel slag filter to evaluate its effect on total P (TP), dissolved reactive P (DRP), and total suspended solids (TSS). Research was also conducted on pH reduction for filter effluent. Results indicate that the filter removed 95.83% of TP, 96.65% of DRP, and 52.25% of TSS. Average pH effluent was measured at 10.12 ±1.55. Additionally, a field study was conducted on sampling two unlined bioretention systems treating urban stormwater runoff. Methods used are presented and methodological considerations for future studies are presented to guide researchers in more effective and efficient methods for obtaining influent and effluent samples from bioretention systems that are not necessarily designed for sampling.

Nutrient inputs into the environment greatly impact urban ecosystems. Appropriate management strategies are needed to limit eutrophication of surface water bodies and contamination of groundwater. In many existing urban environments, retrofits or complete upgrades are needed for stormwater and/or wastewater infrastructure to manage nutrients. However, sustainable urban nutrient management requires comprehensive baseline data that is often not available. A Framework for Urban Nutrient (FUN) Management for Geographic Information Systems (GIS) was developed to specifically address those areas with limited data access. Using spatial analysis in GIS, it links water quality, land use, and socio-demographics, thereby reducing data collection and field-based surveying efforts. It also presents preliminary results in a visually accessible format, potentially improving how data is shared and discussed amongst diverse stakeholders. This framework was applied to two case studies, one in Orange County Florida and one in Placencia, Belize. A stormwater pond index (SPI) was developed to evaluate 961 residential wet ponds in Orange County, Florida where data was available for land use and socio-demographic parameters, but limited for water quality. The SPI consisted of three categories (recreation, aesthetics, education) with a total of 13 indicators and provided a way to score the cultural and ecosystem services of 41 ponds based on available data. Using only three indicators (presence of a fence, Dissolved Oxygen (DO) < 4 mg/l, and water depth < 3 ft), 371 out of 961 stormwater ponds were assessed. Additional criteria based on socio-demographic information (distance to a school, population density, median household income under $50,000, percentage of population below the poverty line, and distance to parks) identified seven wet ponds as optimum for potential intervention to benefit residents and urban nutrient management purposes. For the second case study, a water quality analysis and impact assessment was performed for the Placencia peninsula and lagoon in Belize. This study had access to water quality data, but limited land use data and very limited socio-demographic data. Since May 2014, water quality samples have been taken from 56 locations and analyzed monthly. For this study, Dissolved Oxygen (DO), Nitrate (NO3--N), Ammonia (NH3), Chemical Oxygen Demand (COD), and 5-Day Biochemical Oxygen Demand (BOD5), Escherichia coli (E. coli), and Enterococci were selected to assess spatial and temporal variation of water quality in the groundwater on the peninsula as well as the surface water in lagoon, estuaries and along the coast. A spline interpolation of DO, Nitrate, BOD5, and COD for June 2016 indicated the concentration distribution of those parameters and areas of special concern. A spatial analysis was conducted that showed that Nitrate and Enterococci exceeded the effluent limits of Belize very frequently in the complete study area while the other parameters contributed to the identification of key areas of concern. As a high variability of concentrations over time was observed, a temporal analysis was conducted identifying a link between the water quality data and two temporal impact factors, rainfall and tourism. The two case studies showed the broad and flexible application of the FUN management for GIS and the great advantages the use of GIS offers to reduce costs and resources use.

Sur le bassin Méditerranéen, l'utilisation des ressources en eau est en constante augmentation depuis plus de cinquante ans. Avec les trois quart des ressources en eau d'origine superficielle, l'exploitation des eaux souterraines apparaît comme une des solutions à la raréfaction de l'eau. Les aquifères karstiques semblent répondre à cette démarche car ils possèdent une réserve en eau importante et facilement renouvelable. L'hydrosystème Cesse-Pouzols, situé dans le Sud de la France, regroupe le bassin versant karstique de la Cesse (275 km²) et l'aquifère karstique de Pouzols. A la limite entre les Corbières au Sud, la Montagne Noire au Nord et le chaînon de St-Chinian à l'Est, sa géologie et sa géométrie sont complexes car héritées des grands évènements tectoniques du Languedoc Roussillon. Durant le quaternaire, l'enfoncement et les changements de cours de la Cesse, ont permis au réseau karstique de se développer, laissant apparaître des zones de pertes et résurgences. La synthèse de l'évolution hydro-géomorphologique du bassin a permis d'établir un premier schéma de fonctionnement hydrogéologique. La description des réseaux de mesures présents et nouvellement installés a permis de regrouper l'ensemble des données pluviométriques, débitmétriques et piézométriques disponibles sur cet hydrosystème permettant l'amélioration des connaissances du site par une analyse hydrodynamique et hydrochimique. Ces analyses ont permis d'identifier les interactions entre eau de surface et eau souterraine, la présence d'une réserve en eau importante au travers d'une bonne conductivité hydraulique ainsi qu'une forte capacité de stockage, une zone de recharge située à l'altitude moyenne du contact entre les terrains calcaires Tertiaires et les terrains Primaires de la Montagne Noire ainsi qu'un mélange entre des eaux très anciennes et des eaux récentes a également été mise en évidence notamment grâce à l'utilisation des isotopes stables de l'eau et les gaz anthropiques (CFCs et SF6). Afin d'estimer un volume maximum prélevable et de proposer une gestion active de l'hydrosystème Cesse-Pouzols, une modélisation conceptuelle globale journalière basées sur le GR4J a été développée. Puis, il a été choisi de développer ce modèle par intégration des interactions surface/souterrain et par la prise en compte des écoulements lents et rapides. Le GR5J ainsi développé, montre des résultats significativement supérieurs au GR4J. La prise en compte des interactions entre les réservoirs de l'aquifère a permis d'élaborer un GR7J. Toutefois, le GR7J ne présente pas d'amélioration nette par rapport au GR5J et fait état d'une « sur-paramétrisation » face aux données disponible aujourd'hui. Le GR5J a donc été utilisé dans la détermination du volume maximum prélevable d'eau souterraine. Malgré les limites de modélisation, le GR5J a été appliqué afin d'illustrer la méthodologie proposée. Le volume prélevable pour l'aquifère de Pouzols est estimé entre 4,5 et 6 millions de m3 par an. Toutefois ce chiffre doit être modulé en fonction de l'établissement du futur débit biologique de la Cesse et de la valeur des prélèvements de surface présents dans le cours pérennes de la rivière. / During the past fifty years, water use has been on a constant increase over the Mediterranean basin, Three quarters of water withdrawals come from superficial water resources. Thus, groundwater resources appears as a solution to surface water rarefaction. karstic groundwater constitutes an important and easily renewable reserve. The Cesse-Pouzols hydrosystem, located in the South of France, is composed by the karstic basin of the Cesse (275 km ²) and the karstic aquifer of Pouzols. At the borderline between the Corbières in the South, the Montagne Noire in the North and the thrust of St-Chinian in the East, its geology and geometry are complex and it inherits from big tectonic events of Languedoc Roussillon. During the quaternary era, karstic network developed owing to changes the Cesse changements of direction , generating zones of losses and resurgences. The synthesis of the basin hydro-geomorphologic evolution allowed establishing a first scheme of its hydrogeological functioning. The description of current networks and newly installed tools allowed collectingrainfall , flow and water table data available on this hydrosystem thusimproving knowledge of the site by a hydrodynamic and hydrochemical analysis. Thanks to these analyses (i) correlations between surface and groundwater were identified as well as(ii) the presence of an important groundwater reserve through a good hydraulic conductivity, (iii) a strong stocking capacity, (iv) a zone of reload located on the medium altitude of contact between the tertiary carbonate formation and the Primary formation of the Montagne Noire. A mixture between very ancient waters and recent waters was also highlighted notably thanks to the use of stable isotopes of water and anthropogenic gases (CFCS and SF6). In order to estimate the maximum volume of groundwater that could possibly be pumped and to offer an active management of the hydrosystem Cesse-Pouzols, a daily conceptual modelling was developed, based on the hydrological model GR4J. It was chosen to develop this model by integration of surface water/groundwater interacations and by the recognition of slow and quick flows. A GR5J model was so developed. The recognition of correlations between the reservoirs of the aquifer allowed setting up a GR7J model. However, GR7J does not introduce net improvement in comparison to GR5J and mentions one «over - parameterization» according to today's available data. The GR5J model was therefore used Maximum volume of groundwater pumped in Pouzols aquifer is estimated between 4,5 and 6 millions of m3 per year. However, this figure must be modulated according to the future environmental flow of the Cesse and to the value of the present samples of the river.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Timothy Keane / Stormwater management within the urban context has evolved over time. This evolution has been categorized by five paradigm shifts (Novotny, Ahern, & Brown, 2010). The current paradigm of stormwater management utilizes hard conveyance and treatment infrastructure designed mainly to provide protection for people from typical 1-5 year frequency storms. Consequently, this infrastructure is sometimes unable to deal with larger sized, 50 to 100 year events which can have serious consequences. Manhattan, Kansas has suffered multiple flooding episodes of severe proportion in the past decade. The dilemma of flooding within the Wildcat Creek watershed is a direct example of the current paradigm of stormwater management. This once ecologically healthy corridor is fed by conveyance systems that do not address the hydrologic needs of the watershed; decreasing the possibility for infiltration and groundwater recharge. Vegetated stormwater management systems must be implemented to help increase infiltration and address flooding problems within the Wildcat Creek watershed. The aesthetic performance of designed landscapes has a tremendous effect on the appreciation and care given to them by the surrounding population (Gobster, Nassauer, Daniel, and Fry, 2007). Landscape architecture has the ability to aid in the visual appeal and ecological design of vegetated stormwater management systems (SMS) by utilizing existing frameworks that address aesthetic reaction of the outdoor environment (Kaplan, Kaplan, and Ryan, 1998). This document evaluates design alternatives of vegetated SMS in order to discern a set of variables that inform the relationship between each systems aesthetic and amenity performance and their ecosystem and hydrological performance. Identified variables are combined into a set of guidelines for achieving different levels, or patterns of aesthetic performance found within the Understanding and Exploration Framework et al. (Kaplan, Kaplan, and Ryan, 1998) and amenity performance listed by Echols and Pennypacker’s Amenity Goals et al. (2007) through vegetated SMS. These design guidelines illustrate how aesthetic theory can be applied through ecological systems in order to increase the coherence, legibility, complexity, and mystery (Kaplan & Kaplan, 1989) of existing sites. Creating spaces where ecological and socio-cultural activities can coexist addresses the local characteristics of aesthetics with the universal dilemma of stormwater management.