Pilot Watershed Research Articles

Assessing the Feasibility and Socioecological Benefits of Climate-Smart Practices at the Watershed Scale

Resource allocation in climate-smart productive practices depends on the explicit recognition and accountability of the expected costs and benefits in socioeconomic and ecological terms. This study assessed the private and social costs and benefits of 10 practices compatible with the transition to sustainable agricultural practices under an integrated landscape management (ILM) approach. First, the financial and economic viability of the alternatives was evaluated with a cost-benefit analysis. Then, the potential contribution of these practices in terms of carbon sequestration and landscape connectivity was determined in an ILM scenario where at least three practices (live fences, isolated trees in pastures, and riparian vegetation recovery) could be implemented and assessed at the watershed scale. These practices were evaluated in three Mexican pilot watersheds with contrasting biophysical and sociocultural contexts but with high importance in biodiversity conservation and cattle production. The results showed that most climate-smart practices are viable in the medium and long term from a private standpoint. However, more significant benefits are achievable over a shorter period when social co-benefits are included. The results could contribute to decision-making in terms of public policy, providing evidence of the financial and economic feasibility of the analyzed climate-smart practices that also have ecological benefits. In this sense, decision-makers who promote such practices have more arguments to seek funding for implementation.

Building climate resilience in degraded agricultural landscapes through water management: A case study of Bundelkhand region, Central India

Rainfall variability and water scarcity continue to hamper the food and income security of smallholder farming systems in poverty-affected regions. Innovations in soil and water management, especially in the drylands, are critical for meeting food security and water productivity targets of Agenda 2030. This study analyzes how rainfed agriculture can be intensified with marginal impact on the landscape water balance. The impact of rainwater harvesting structures on landscape hydrology and associated agricultural services was analyzed in the semi-arid Jhansi district of Bundelkhand region in central India. The Parasai-Sindh pilot watershed was subjected to a 5-year (2012–2016) monitoring of rainfed system improvements in water availability and crop intensification due to surface water storage (haveli system), check dams, and field infiltration structures. Hydrological processes were monitored intensively to analyze the landscape’s water balance components. Rainwater harvesting (RWH) structures altered the landscape’s hydrology, limiting average surface runoff from 250 mm/year to 150 mm/year over the study period. Groundwater levels increased by 2–5 m (m), alleviating water scarcity issues of the communities in recurring dry years. Nearly 20% of fallow lands were brought under cultivation. Crop yields increased by 10–70% and average household income increased from US$ 960/year to US$ 2700/year compared to that in the non-intervention landscape. The combined soil–water–vegetation efforts strengthened water resilience and environmental systems in agricultural landscape.

Digital soil mapping including additional point sampling in Posses ecosystem services pilot watershed, southeastern Brazil

This study aimed to evaluate the performance of three spatial association models used in digital soil mapping and the effects of additional point sampling in a steep-slope watershed (1,200 ha). A soil survey was carried out and 74 soil profiles were analyzed. The tested models were: Multinomial logistic regression (MLR), C5 decision tree (C5-DT) and Random forest (RF). In order to reduce the effects of an imbalanced dataset on the accuracy of the tested models, additional sampling retrieved by photointerpretation was necessary. Accuracy assessment was based on aggregated data from a proportional 5-fold cross-validation procedure. Extrapolation assessment was based on the multivariate environmental similarity surface (MESS). The RF model including additional sampling (RF*) showed the best performance among the tested models (overall accuracy = 49%, kappa index = 0.33). The RF* allowed to link soil mapping units (SMU) and, in the case of less-common soil classes in the watershed, to set specific conditions of occurrence on the space of terrain-attributes. MESS analysis showed reliable outputs for 82.5% of the watershed. SMU distribution across the watershed was: Typic Rhodudult (56%), Typic Hapludult* (13%), Typic Dystrudept (10%), Typic Endoaquent + Fluventic Dystrudept (10%), Typic Hapludult (9.5%) and Rhodic Hapludox + Typic Hapludox (2%).

The Jaguaré Creek Revitalization Project: Transforming São Paulo through a Green Stormwater Infrastructure

The surrender of environment and landscape to the pressure of fast rural-urban transition has labelled São Paulo as the ‘Metropolis of Polluted Waters’ worldwide. How can the largest city in Latin America consider this issue of metropolitan dimensions: recover its large sewage rivers and reframe for resilience? The Jaguaré Creek Revitalization Project understands that this recovery depends on a fractionated, but integrated performance over all territories that generate pollution to water resources. Jaguaré Creek watershed corresponds to only 1/10 of the total 270km2 drainage area of Pinheiros River, one of the two main watercourses crossing Greater São Paulo and that is channeled in all its 25Km length. Its waters carry significant load of domestic and industrial sewage and other non-point sources as well. Regarding the failure of all previous public efforts, reversing this scenario requires innovation and an integrated system made of coordinated actions and based on technology, urban planning and advocacy. In order to restore this pilot watershed, the Jaguaré Project is coordinated by Águas Claras do Rio Pinheiros Organization and developed by a multidisciplinary team of researchers including engineers, landscape architects, urban planners, managers, among others, acting in two complementary fronts: 1. Interception and combined treatment of stormwater and sewage illegally discharged into underground drainage system; 2. Non-source point pollution control and runoff management through a Green Stormwater Infrastructure. For this second front, pollutant loads will be measured by runoff samples collected in predefined catchment areas. By associating the sample analysis results with the land use typologies within these areas, surface pollution loads may be quantified for the whole Jaguaré watershed. The sizing of the problem will lead to an optimized distribution of stormwater management LID structures. Rain gardens, bioswales, retention ponds, green roofs and pervious pavements will convey, filter, retain and infiltrate stormwater, respecting the most suitable drainage function to physical and environmental conditions. They will form a green network for urban drainage with greater bond with nature processes, landscape and people. By restoring creeks, São Paulo reclaims its rivers. By saving the rivers, the city will move towards transformation.

Land suitability for final waste disposal with emphasis on septic systems installation in southern Minas Gerais, Brazil

ABSTRACT Environmental pollution is a problem that has been noted due to changes in the environment, affecting natural resources. Regarding the soil, it may offer great potential for waste disposal. Thus, this study aims to propose criteria for evaluating local suitability for waste disposal, according to soil and terrain attributes for southern Minas Gerais State, and to apply those criteria to define the most appropriate locations for installation of septic systems in a pilot watershed. Literature and the authors' experience were used to propose the more important criteria regarding the suitability of sites for waste disposal. The set of attributes taken into account was grouped into four suitability classes: Adequate, Regular, Restricted and Inadequate. The defined criteria and considered limiting were: soil depth, texture, textural gradient, structure, natural drainage, water infiltration, type of surface horizon, water table depth, depth of perched water table, distance from water bodies, relief, stoniness, rockiness and risk of flooding. From these, soil depth, natural drainage, water table depth, relief and distance from water bodies were adopted for the installation of septic systems. From the total area of the watershed, 5.29% fit in the Adequate suitability class. The Regular, Restricted, and Inadequate sites accounted for, respectively, 19.72%, 41.99% and 33% of the wathershed. Factors such as soil and terrain attributes provide a basis for defining more appropriate places for waste disposal. Future work should involve the refinement of these propositions, since there are rare studies in this research line in Brazil.

Land use change impacts on water quality in three lake winnipeg watersheds.

Lake Winnipeg eutrophication results from excess nutrient loading due to agricultural activities across the watershed. Estimating nonpoint-source pollution and the mitigation effects of beneficial management practices (BMPs) is an important step in protecting the water quality of streams and receiving waters. The use of computer models to systematically compare different landscapes and agricultural systems across the Red-Assiniboine basin has not been attempted at watersheds of this size in Manitoba. In this study, the Soil and Water Assessment Tool was applied and calibrated for three pilot watersheds of the Lake Winnipeg basin. Monthly flow calibration yielded overall satisfactory Nash-Sutcliffe efficiency (NSE), with values above 0.7 for all simulations. Total phosphorus (TP) calibration NSE ranged from 0.64 to 0.76, total N (TN) ranged from 0.22 to 0.75, and total suspended solids (TSS) ranged from 0.29 to 0.68. Based on the assessment of the TP exceedance levels from 1993 to 2007, annual loads were above proposed objectives for the three watersheds more than half of the time. Four BMP scenarios based on land use changes were studied in the watersheds: annual cropland to hay land (ACHL), wetland restoration (WR), marginal annual cropland conversion to hay land (MACHL), and wetland restoration on marginal cropland (WRMAC). Of these land use change scenarios, ACHL had the greatest impact: TSS loads were reduced by 33 to 65%, TN by 58 to 82%, and TP by 38 to 72% over the simulation period. By analyzing unit area and percentage of load reduction, the results indicate that the WR and WRMAC scenarios had a significant impact on water quality in high loading zones in the three watersheds. Such reductions of sediment, N, and P are possible through land use change scenarios, suggesting that land conservation should be a key component of any Lake Winnipeg restoration strategy.

Sensitivity analysis of main variables present in flash flood processes. Application in two Spanish catchments: Arás and Aguilón

The program Simulation of Hydrological Extreme Events provides a set of functionalities that combined together allows constructing, manipulating, analyzing and comparing the hydrological processes involved in flash flood generation. The program makes use of existing databases of interest in hydrology and available in Spain, such as digital terrain models, coverage of rainfall or curve number. Two pilot watersheds from Spain were selected, Aras and Aguilon, where flash flood episodes have taken place. A sensitivity analysis of the flash flood episodes in response to changes in the main hydrological processes involved has been made, such as spatial and temporal distribution of rainfall, soil moisture status and water flow through channel network. In this work, we found that the antecedent moisture condition is the most influential factor in the magnitude of flash floods produced by the same amount of rain. The temporal distribution of the storm represents the second characteristic in order of relevance. In addition, terrain morphology (specially the slope) is found to be decisive in the results differences obtained.

Hydrological modelling of Toxoplasma gondii oocysts transport to investigate contaminated snowmelt runoff as a potential source of infection for marine mammals in the Canadian Arctic

Toxoplasma gondii (T. gondii) is a zoonotic protozoan that sometimes causes serious illness in humans and other animals worldwide, including the Canadian Arctic. Wild and domestic felids, the only hosts able to shed T. gondii oocysts, are practically non-existent in the Canadian Arctic. So here the hypothesis that T. gondii oocysts, shed in the southern areas of the boreal watershed, could contaminate the Arctic coastal marine environment via surface runoff, particularly during the spring snowmelt period, was explored. A watershed model was applied to simulate the hydrological transport of T. gondii oocysts during the snowmelt period and test the possible efficiency of river-to-sea transport as a potential source of marine organisms' exposure to this pathogen. Simulations were run for two pilot watersheds with the ultimate aim of extrapolating the results across the Canadian Arctic watersheds. Results suggest that daily stream flow concentrations of T. gondii oocysts at the river outlet are likely to be very low. However, accumulation of oocysts in the estuarine areas may be large enough to contaminate estuarine/marine filter-feeding molluscs and snails on which seals and other marine mammals may feed. Potential maximum concentrations of T. gondii oocysts in runoff are reached at the beginning of the snowmelt period with maxima varying with discharge rates into rivers and how far upstream oocysts are discharged. Meteorological conditions during the snowmelt period can affect simulated concentrations of oocysts. These findings support the hypothesis that T. gondii oocysts carried in snowmelt runoff could be a source of T. gondii infection for marine mammals in the Canadian Arctic, and for Arctic human populations that hunt and consume raw meat from marine mammals.

Assessment of the effects of agricultural practices on non-point source pollution for a coastal watershed: A case study Nif Watershed, Turkey

Best management practices (BMPs) are increasingly being used by decision makers to reduce agricultural non-point source (NPS) pollution while improving productivity for the farmers. Models are used as planning tools and are especially useful for targeting priority areas for BMP implementation. This study describes a modeling system to assess the impacts of agricultural NPS pollution on coastal environments. The approach is based on Remote Sensing (RS), Geographical Information Systems (GIS) and Hydrological Modeling (HM) and applied to a pilot watershed – catchment area of Nif Creek – in the Aegean region of Turkey. Land Use and Land Cover (LULC) map of the selected area is produced from LANDSAT MSS image based on Co-ordination of Information on the Environment (CORINE) classification scheme. Simulator for Water Resources in Rural Basins (SWRRB-WQ) was used to estimate the NPS pollution loads. The effects of agricultural management practices such as application of irrigation, fertilizer and tillage on the streamflow quality and quantity can be determined by such a modeling system.

Water balance in the Guarani Aquifer outcrop zone based on hydrogeologic monitoring

Summary Main objective of this work was the study of the infiltration and recharge mechanisms in the Guarani Aquifer System (GAS) outcrop zone. The study was based on hydrogeologic monitoring, evapotranspiration and water balance in a pilot watershed. The pilot watershed (Ribeirao da Onca) is situated in the outcrop zone of the Guarani Aquifer between parallels 22°10′ and 22°15′ (south latitude) and meridians 47°55′ and 48°00′ (west longitude). For the execution of the research project, a monitoring network (wells, rain gauge and linigraph) was installed in the watershed. Data have been systematically collected during the period of a hydrological year. Water level fluctuation has been used to estimate deep recharge and subsurface storage variation. The method used to estimate the direct recharge adopted the hypothesis that the recession of the groundwater level obeys a function of power law type. Direct recharge is obtained through the difference between the actual level of an unconfined aquifer and the level indicated by extrapolation of the recession curve, in a given period. Base outflow is estimated through a mixed function (linear and exponential). Outflow in the creek has been measured with current meter and monitored continuously with a linigraph. The annual infiltration in 2005 was estimated to be 350 mm, while the deep recharge, based on water balance, appears to be 3.5% of the precipitation (1410 mm). These results indicate that the estimated long term water availability of the Guarani Aquifer System should be studied more carefully.

Evaluating the ecological status of rivers using an index of ecological distance: An application to diatom communities

Abstract Community structure changes with pollution or stress. In the Water Framework Directive, high ecological status through biological parameters is defined as a slight or minor deviation from the reference community, while the good status is defined as a small deviation. To assess the importance of this deviation, and then to measure the degradation of ecological status along a river, an index based on the concept of “ecological distance” between species was created and called ecological distance index (EDI). It was tested on diatom data from a pilot watershed (the Garonne river basin, South-West France). The results show a good correlation between the EDI and the IPS (Indice de Pollusensibilite Specifique – specific pollusensitivity index – a diatom-based biotic index) ecological ratios, which means first that the EDI is a valuable indicator of ecological status, and that it can account for ecoregional specificities. This index can be applied to any communities (macro-invertebrates, fish, etc.), since: (i) typical reference communities are found for each river type; (ii) species are characterised then ranked by pollution sensitivity values.

Modelling Changes in Stream Water Quality Due to Climate Change in a Southern Ontario Watershed

This research represents a pilot project to establish a methodology for assessing the sensitivity of watershed stream water quality to changes in water quantity caused by climate change. The pilot watershed is the Duffins Creek watershed, located 20 km east of the City of Toronto, Canada. Scenarios of climate change analyzed in this project were drawn from two internationally recognized climate models: the Canadian Centre for Climate Modelling and Analysis (CCCma) CGCM1 and the Hadley Centre HadCM2. The AGNPS (Agricultural Non-Point Source) model was used to predict changes in stream water chemistry. The results are compared to baseline conditions as well as future conditions based on 2020 land use scenarios. It was determined that 2020 land use scenarios typically result in much smaller changes in peak flows than are predicted for the climate change scenarios, especially the wet climate change scenarios. Understanding climate change responses is critical for the development of watershed plans and drinking water source protection studies. Currently, watershed studies are completed using climate information based on relatively short-term monitoring databases that reflect past weather patterns. It is widely understood that management actions advocated in watershed studies could be improved if consideration were given to the implication of climate changes.

EFFECTWENESS OF INTEGRATED STORMWATER MANAGEMENT IN A PORTLAND, OREGON, WATERSHED1

ABSTRACT: The City of Portland's stormwater management program, winner of EPA's Environmental Excellence Award for 1996, is committed to partnership‐based, cost‐effective, “green” approaches to healthy neighborhoods and water quality. The stormwater program encourages innovative, non‐structural pollution reduction techniques like native landscaping, stormwater pollution reduction bioswales and ponds, and public involvement and education.Effectiveness of stormwater best management practices (BMPs) has been difficult to determine on a citywide basis. Recognizing this problem, the City of Portland launched the Parkrose Pilot Project in 1994 to test the effectiveness of a wide range of BMPs in a small watershed in north Portland, the Parkrose catchment, and monitor the results prior to citywide implementation. This catchment was selected because of its small size (144 acres), its representative mix of land uses, and an extensive record of water quality monitoring data.This paper examines the City's strategy in selecting the Parkrose study area as a pilot watershed, the BMPs chosen for use in the watershed, and the results of the program to date. Final success of the Parkrose project will be gauged by the attainment of measurable pollution reduction within the catchment while providing opportunities for meaningful participation by the local community in achieving water quality. Involvement by private citizens in the community is crucial to the success of the project and to ensure compliance with the federal mandate to reduce pollutants to the maximum extent practicable.

Agriculture and Water Quality in the Canadian Great Lakes Basin: I. Representative Agricultural Watersheds

AbstractThe 1972 U.S.‐Canada Great Lakes Water Quality Agreement established the Pollution from Land Use Activities Reference Group (PLUARG). To meet the objectives of the Pilot Watershed Studies of PLUARG, an approach was developed tbat would allow the quantification of the agricultural component of Great Lakes drainage basin pollution loads. A primary separation of agricultural regions was based on an index of the soil's potential to transfer pollutants to surface and ground water. Agricultural watersheds representative of major soils‐crops‐livestock combinations were monitored and studied. Selection and preliminary monitoring processes led to 11 sites being monitored for 2 years.The areas of the 11 study watersheds ranged from 20 to 79 km2, of which 22–89% was cultivated, and 0–99% tile‐drained. Row‐cropped laud, which occupied 10–66% of the watershed areas, was strongly correlated with tile‐drained area and fertilizer use. Mean surface‐soil clay contents ranged from 7 to 36%. Livestock densities were negligible in some watersheds, but were up to 0.77 animal units ha−1 in others. Mean precipitation and stream discharge during the study period were approximately 9 and 26% higher, respectively, than expected from long‐term means. The proportion of annual precipitation occurring in the January–April period averaged 32%, while approximately 65% of the stream discharge was measured during these 4 months.Intensive flow‐related stream sampling and chemical analyses revealed that the watersheds yielded a wide range of nutrient, sediment, and pesticide loadings to Great Lakes tributaries. The subsequent papers in this series discuss these results and their significance to water quality in the Great Lakes Basin.

Relationship of Water Quality and Pollutant Loads to Land Uses in adjoining watersheds1

ABSTRACT: The Grand and Saugeen Rivers in southern Ontario were chosen for study as pilot watersheds under the Pollution From Land Use Activities Reference Group (PLUARG) study. The pilot watersheds have adjacent headwater areas and are physically similar in geology, physiography, and climate. Significant differences in water quality between the watersheds at their outlets are attributed to land use and population differences. The major pollutant sources in the two pilot watersheds were identified as trace elements from urban runoff and point source discharges; phosphorus from agricultural and urban runoff and private waste disposal; chloride from transportation corridors; and sediment and nitrogen from agricultural runoff. Yields at the watershed outlets were similar for suspended sediment and two to three times as high in the Grand River for phosphours, nitrogen, chloride, and lead. The higher phosphorus and nitrogen levels were attributed to larger point source inputs and the higher proportion of agricultural activity, comprising 75 percent of the Grand River basin compared to 64 percent in the Saugeen River basin. Similarly, the higher chloride and lead levels were attributed to an order of magnitude larger population and three times as much urban land in the Grand River basin compared to the Saugeen River basin.

Effects of Stream Channeling on Wetlands in a Minnesota Watershed

Over 60 miles of stream was channeled in the lower three quarters of the Hawk Creek Watershed, west-central Minnesota. Ite channels permitted more rapid removal of flood waters but also encouraged construction of ditches and tilees by providing improved outlets. Wetlands valuable to waterfowl and other wildlife were drained as a result. On a percentage basis, wetland loss in the lower part of the watershed was nine times greater than in the unchanneled upper quarter. BRIEFER ARTICLES This paper presents a case history of a federally assisted, stream-channeling project and resultant wetland loss in the Hawk Greek Watershed, Minnesota. Streams straightened and deepened (channeled) to remove flood waters rapidly and to improve land for agriculture under federal watershed programs encourage drainage of adjacent wetlands valuable to wildlife. These losses are seldon1 measured and documented. The Hawk Creek Watershed is 1 of 11 pilot watershveds established under ffie Flood Control Act of 1936. These watersheds were to be managed with fish, wildlife, and recreational values in mind, as well as for flood control and agricultural purposes. Funds and technical assistance were made available through the U. S. Department of Agriculture. Pilot watersheds were forerunners of those administered under the small watershed program of Public Law 83-566 passed in 1954. I express appreciation to R. Jessen, Minnesota Division of Game and Fish, who initiated the study and reviewed the manuscript. E. Huber, O. Jarvenpa7 and Dr. J. Supported by Federal Aid Project FW-1-R-15. 2 Present address: New Brunswick Fish and Wildlife Branch, Fredericton. 940 Moyle of the same organization, and Dr. K. Harmon, Wildlife Management Institute, provided editorial assistance. HAWK CREEK WATERSHED Hawk Creek drains 502.4 square miles (321,553 acres) in Chippewa, Kandiyohi, and Renville counties of west-central Minnesota and empties into the Minnesota River. A major tributary, Chetomba Creek, drains the eastern part of the watershed and joins Hawk Creek near the lower end (Fig. 1). Much of the watershed is excellent farmland with corn, soybeans, and small grains the principal crops. The topography is rolling to nearly level. Soils7 developed from calcareous glacial tilln are in the Clarion-Nicollet-Webster and Barnes-Aastad-Flom associations ( Arneman 1963:5). Undrained and poorly drained depressions were originally occupied by highly productive shallow lakes and marshes. Although the number of these is unknown) it must have been considerable.

Erratum for “Status of Pilot Watershed Studies in Arizona”

Erratum for “Status of Pilot Watershed Studies in Arizona”

Status of Pilot Watershed Studies in Arizona

Critical water shortages in Arizona have led to intensive investigations of methods for increasing streamflow from the state’s watersheds. These investigations include research studies of hydrologic processes and behavior, pilot tests of promising treatments, economic studies, and surveys of potentially treatable areas. Results are reported from pilot tests in chaparral, juniper, ponderosa pine, and mixed-conifer vegetation types. To date, streamflow responses following watershed treatments have varied from zero to as much as 9 in. per year, depending on nature of the treatment, type of vegetation, and climate. These results and others forthcoming will play an important role in future multiple use management of forest lands in Arizona.