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With the ever increasing demand for potable water due to the continued increase in population coupled with the threat of California’s current drought, water will remain a limited resource that must be managed responsibly. In order to strategically plan and manage water use in the most beneficial manner, water providers must take into account all sources of water, including recycled water and their applications. Recycled water as a source for supplementing high quality potable water is a sustainable strategy that will prove to be an essential tactic in any water management plan. The purpose of this project is to emphasize the importance of supplementing potable water in the City of Banning by discussing the characteristics of California’s current water drought; evaluating the City of Banning’s available water supplies and current water demand; discussing the Soil Aquifer Treatment process; summarizing California’s regulations related to recycled water; and discussing the quality of recycled water available at NP-1, an unequipped City owned water well, by examining water quality testing on water samples taken from NP-1. Analysis of water available at NP-1 showed that with additional disinfection, the water pumped from NP-1 could meet the recycled water requirements in order to be used on a local golf course. The local golf course is currently being irrigated with potable water, which would be supplemented with the recycled water from NP-1.

Brown trout (Salmo trutta), one of the world’s most successful introduced species, negatively impacts native aquatic communities through predation, competition, and ecosystemlevel effects. Thus, there is a need to understand factors controlling the distribution of exotic brown trout in river systems, in order to prioritize and develop conservation and management strategies. Within the context of invasion success, I investigated how the physical template of the Logan River influences the distribution of brown trout along a longitudinal gradient, and the potential for brown trout predation on the native mottled sculpin (Cottus bairdi). The Logan River, Utah USA, is a high-elevation, mountain river exhibiting a wide range of physical habitat characteristics along the altitudinal (or elevational) gradient. In chapter 1, I evaluated whether longitudinal trends in geomorphology contribute to higher potential mortality of brown trout fry at high elevations due to flood-caused streambed scour. High-elevation spawning gravels did not exhibit higher scour compared to low elevations, because brown trout locally chose low-scour areas for spawning. In chapter 2, I investigated the importance of gravel availability, versus other habitat factors, in controlling the spatial distribution of brown trout redd densities. Using a Bayesian hierarchical modeling approach, I demonstrated that anchor ice, distance from high-quality backwater habitat, and to a lesser-extent gravel availability, best explained redd densities. Finally, in chapter 3, I evaluated the potential predatory effects of exotic brown trout on native mottled sculpin (Cottus bairdi). High rates of sculpin consumption contrasted to previously documented low rates of predation by native Bonneville cutthroat (Oncorhynchus clarkii) and depended on abiotic factors controlling the distribution of both species. Collectively, my research suggests that both abiotic factors and source-population dynamics structure brown trout distributions on the Logan River, and ultimately the potential impacts of this invasive fish. Specifically, the distribution of anchor ice and distance from dam backwaters are important drivers of the brown trout distribution, which may extend to other systems. These drivers, including how they may be influenced by future climate change and habitat alteration, should be considered in management efforts to control brown trout expansion and to limit the predatory impacts of brown trout.

The Ayuquila River watershed is important to western Mexico because of its biodiversity, physiography, fisheries resources, and water production. However, human activities are continuingly affecting natural resources within the basin. Soil erosion, as result of land use change, agriculture in steep land, extensive grazing activities and forest fires; and water diversion and pollution of the Ayuquila River are two relevant issues that have affected the natural resources of this watershed. This river system plays an important role in wildlife conservation, containing 29 fish species, of which 12 are found inside the BRSM. The River also contains nine species of crustacean, one that is endemic to Jalisco State. The otter (Lontra longicaudis), a species threatened within the BRSM, is found in the Ayuquila- Armeria River watershed. This research focused on the reduction of river pollution and the reduction of negative impacts of water pollution delivered to those communities, some of the poorest in the state of Jalisco, that live downstream of the valley. This research was also designed as a way to increase the knowledge of soil erosion processes and water quantity and quality in tropical environments and to test and develop new tools that might facilitate parameter estimation and predictive capabilities within the Ayuquila River watershed. Research efforts in this dissertation had focused on the development of new scientific information about point and nonpoint-source pollution within the Ayuquila River based on three main research studies, the investigation into trail erosion, the production of an erosion sensitive map, and documenting and modeling water quantity and quality in the Ayuquila Watershed. Major concerns that this research seeks to contribute a solution, is to reduce negative impacts on public health, degradation in fisheries resources as source of local food supply, domestic water supplies for those communities, some of the poorest in the state of Jalisco, that live downstream the valley and that do not receive any benefit from the economic development of the Autlan- El Grullo Valley. Results from the commercial trail study, with sediment productions close to 100 ton/ha/yr, showed the importance of the application of conservation practices to reduce the potential erosion from commercial trails in my study area and potentially other tropical forests of Latin-American. The WEPP model used to predict soil erosion in the tropical mountain environments of Mexico was shown to be an adequate tool even with WEPP's limitations for tropical soil environments. WEPP effectively contributed to the estimation of sediment plume production on trails, detected vegetation type differences in runoff and soil erosion, predicted the amount of rainfall as runoff well, and adequately developed soil erosion sensitive maps. Water diversion and pollution within the Ayuquila River are important sources of disturbance in the ecological conditions of riparian ecosystems. These two impacts cause a potential break in the ecological continuity of the Ayuquila River. Water quantity and quality modeling will provide opportunities for discussion and analysis of alternatives to water management and possible impacts to the river.

To protect and restore the biological integrity of streams, we need to be able to both detect biological degradation and infer likely causes of impairment. Managers often use biological indices to measure biological condition and detect degradation. However, the ability to detect degradation can be limited by the performance of the indices we develop. Index performance varies widely, but the sources of this variation are often unclear. In addition, although bioassessments are useful tools for detecting biological degradation, they do not identify stressors associated with impairment. My thesis research had two general goals: 1) develop statistically and ecologically robust indices to measure biological condition in Nevada streams and 2) quantify relationships between land uses, stressors, and biological condition to infer likely causes of degradation. I developed two biological indices for Nevada streams, a multimetric index (MMI) and observed to expected (O/E) taxa ratios, and determined if index performance was related to site isolation and sample evenness. The Nevada O/E indices were relatively imprecise compared with those from other regions, which likely results from low assemblage predictability associated with spatial isolation of aquatic habitats in arid regions. In contrast, the Nevada MMI was more precise than most previously developed MMIs, likely the result of using models to reduce natural variation in index scores. Sample evenness was positively associated with both O/E and MMI scores. Adjustments of index scores for sample evenness increased index precision, but also altered relative differences in index values and therefore inferences of biological impairment at specific sites. I also quantified relationships between biological condition, instream stressors, and land uses and used a weight of evidence approach to infer likely causes of degradation. Land uses such as agriculture, urbanization, and mining were associated with the spatial distributions of instream stressors, and these stressors were associated with variation in biological condition. Total dissolved solids and metal contamination were the stressors most strongly associated with biological condition. By detecting biological degradation and identifying important stressors and their potential sources, the tools I developed should help managers target conservation and restoration efforts and improve their ability to protect freshwater resources.

Catchment geology is known to influence water chemistry, which can significantly affect both species composition and ecosystem processes in streams. However, current predictions of how stream water chemistry varies with geology are limited in both scope and precision, and we have not adequately tested the specific mechanisms by which water chemistry influences stream biota. My dissertation research goals were to (1) develop empirical models to predict natural base-flow water chemistry from catchment geology and other environmental factors, (2) extend these predictions to nutrients to establish more realistic criteria for evaluating water quality, and (3) test the hypothesis that catchment geology significantly influences the composition of stream invertebrate assemblages by restricting weak osmoregulators from streams with low total dissolved solids (TDS). To meet goal 1, I first mapped geologic chemical and physical influences by associating rock properties with geologic map units. I then used these maps and other environmental factors as predictors of electrical conductivity (EC, a measure of TDS), acid neutralization capacity, and calcium, magnesium, and sulfate concentrations. The models explained 58 – 92% of the variance in these five constituents. Rock chemistry was the best predictor of stream water chemistry, followed by temperature, precipitation and other factors. To meet goal 2, I developed empirical models predicting naturally occurring stream total nitrogen and total phosphorus concentrations. These models explained most of the spatial variation among sites in total nitrogen and phosphorus and produced better predictions than previous models. By determining upper prediction limits that incorporated model error, I demonstrated how predictions of nutrient concentrations could be used to set site-specific nutrient criteria and accounted for natural variation among sites better than regional criteria. To meet goal 3, I experimentally manipulated (high and low) EC in both stream-side and laboratory flowthrough microcosms and measured survival, growth, and emergence of 19 invertebrate taxa. Observed variation among taxa in survival between treatments predicted taxon EC optima estimated from field observations (r² = 0.60). Taxa with the greatest differences in survival between treatments also had the highest EC optima, indicating that the inability to persist in low EC likely restricts the distributions of some taxa.

Since the early 20th century, river channels of the Colorado River basin have narrowed, decreasing available riparian and aquatic habitat. Changes are considered to be the result of three major factors: wide-spread water development, increasing hydroclimate variability and the invasion of non-native tamarisk (Tamarix spp.), altering flow regime and sediment supply. Different studies have reached different conclusions about the relative roles of flow regime, sediment supply and tamarisk in causing narrowing. I investigated channel change in the lower Green River within Canyonlands National Park to describe channel changes in the 20th century and understand the roles of shifting flow regime and changing vegetation communities on 20th century channel narrowing. The lower Green River within Canyonlands National Park has narrowed substantially since the late 1800s, resulting in narrower channel. Changes to flood magnitude, rate and timing since 1900, driven by increased water storage and diversion in the Green River basin and declines in annual precipitation, was responsible for inset floodplain formation documented in this study. I used multiple datasets to reconstruct the history of channel narrowing in the lower Green River and identify processes of floodplain formation. In the field, analyses of a floodplain trench were described to identify rate, timing and magnitude of floodplain formation. Channel and floodplain surveys were conducted to determine possible changes in bed elevation. Additionally, I analyzed existing aerial imagery, hydrologic data, and sediment transport data. I applied these techniques to determine how floodplain formation occurred at multiple spatial and temporal scales. My investigation shows that the floodplains of the contemporary lower Green River began forming in the late 1930s and continued to form in the 20th century by inset floodplain formation. During this time period, peak flow and total runoff declined due to climatic changes and human water development. Since the mid-1980s, inset floodplains continued to develop along the lower Green River since the mid-1980s, narrowing the river by an additional 9.4%. Analysis of aerial imagery shows that changes to the floodplain identified in the trench occurred throughout the 61 km of river I studied. Non-native tamarisk (Tamarix spp.) did not drive channel narrowing, though dense stands stabilized banks and likely promoted sediment deposition. Inset floodplain formation reflects changes to flooding resulting from water development and climate change. My findings have implications for the long-term management of the lower Green River and endangered endemic native fishes –particularly the Colorado pikeminnow (Ptychocheilus lucius) and the razorback sucker (Xyrauchen texanus). Collaboration with upstream stakeholders and managers is necessary to preserve elements of the flow regime that preserve channel width and limit channel narrowing.

<p> </p><p>High pressure on water from competing users has changed the past perception of water as gift to water as a resource that requires sustainable management. Management of water resource needs active stakeholders’ involvement for its sustainability. Many organizations along with the national water policy have been calling for active stakeholders’ involvement for management of the resource.  In Usangu catchment conflicts over accessing water between farmers and pastoralists and between upstream and downstream have been common. Water allocation in the catchment has been done without involving stakeholders and adequate consideration of the rivers’ carrying capacity. This study focuses on stakeholders’ involvement in Usangu catchment. Six villages in three sub-catchments were studied and data were collected using questionnaire through face to face interview and focus group discussion. The study found that there is limited stakeholders’ involvement in Usangu catchment. In some places involvement is at basic stage, in other places there is no involvement. Interaction within stakeholders’ category was documented, while no stakeholders’ interaction between sub-catchments was discovered. Moreover, some challenges for active involvement were noted, such as lack of coordination between institutions operating in the catchment, high illiteracy rate and lack of awareness, and with lack of legislation support. The issue of limited stakeholders’ involvement in Usangu catchment is complicated, there is no single and comprehensive solution; integration of different approaches which are cross-sectoral in nature is needed for sustainable water management.</p><p> </p>

Off-site soil erosion has tremendous impacts on the present state of most river systems throughout the United States, contributing sediments to channels mainly as nonpoint pollution resulting from land-use and agricultural practices and leading to sedimentation downstream and downwind, a decrease in the transport capacity of streams, increase in the risk of flooding, filling reservoirs, and eutrophication. A primary focus in examining the problems associated with soil erosion arid ultimately in proposing control measures should be on identifying the sources of the sediment. Therefore, a model that would be able to assess soil erosion needs to start by identifying the sediment sources and delivery paths to channels, link these sediment supply processes to in-channel sediment transport and storage and ultimately to basin sediment yield. This study focuses on the Upper Green River Basin in Kentucky and is concerned with analyzing hillslope erosion rates using The Unit Stream Power Erosion and Deposition soil erosion model (Mitas and Mitasova, 1996) and GIS, and thereby estimating patterns of sediment supply to rivers in order to predict which portions of the channel network are more likely to store large amounts of fine sediments. Results indicate that much of the eroded sediments are redistributed within the hillslope system, but also that a large proportion is delivered to the channel. These predictions have been tested by sampling the fine sediment content of the streambed at key locations along the channel network and comparing the observed patterns to those predicted by the soil erosion model. By linking topographic and soil characteristics with land cover data, it has been concluded that high intensity erosion tends to occur at contact between different vegetation covers, on barren lands and croplands, and 15-25% slopes poorly protected by vegetation. Erosion ""hot spots"" have been identified in the Pitman Creek HUC 05110001-90-130 and 05110001-90-050, both part of the Big Pitman Creek sub-basin, as well as in Mill and Falling Timber Creeks with lower intensity.