World Environmental and Water Resources Congress 2020: Water Resources Planning and Management and Irrigation and Drainage

The “water use efficiency” has become a familiar term amongst the researchers and policy makers around the globe. Water use efficiency is of paramount concern for India, as majority of population and land use are dedicated to agriculture. This paper presents a framework for assessing the water demand and irrigation requirements over Beed District (Maharashtra, India), which is notorious for frequent droughts and a very high number of farmer suicides. In this study, standardized precipitation index (SPI) was used to characterize the historical droughts over the district using the long-term rainfall records. Remotely sensed land use maps were obtained and detailed classification was carried out. Additionally, the crop water requirement over the area was estimated by CropWat 8.0 model. From the ground truth verification, it was concluded that the framework is fairly capable in estimating the agricultural water demand over the district. The results were validated for the year 1972, when the district faced a severe water deficit condition. The irrigation network in Maharashtra is ineffectual despite of having highest number of dams in the country. The proposed framework will help to boost the efficiency of agricultural water use and thus, effective planning and management of available water.

Although the use of new tools and technology for irrigation is becoming more popular, the use of methodology such as evapotranspiration to determine the irrigation amount is relatively old and may result in over or under irrigation. Since crop water requirement is function of many parameters, a thorough study is thus required to determine more important parameters that contribute to estimating crop water requirement. These important parameters then can be used to develop an artificial intelligence model, which is expected to be predicting the crop water requirement with minimum errors. The methodology to predict the crop water requirement presented in this paper consists of the following steps: (a) collecting field and weather data, (b) classifying soil moisture data to estimate crop water requirement, (c) identifying important input variables for the crop water requirement by correlation analysis, and (d) developing artificial intelligence models to predict crop water requirement using the important parameters identified in the previous step. The methodology has been applied to analyze olive field data at the University Agricultural Laboratory (UAL) at California State University Fresno. Results show that past PSM (positive change in soil moisture) data can be used to predict future crop water requirement. Besides PSM, soil temperature (ST) and cumulative evapotranspiration (CET) show higher correlation when they are used as a single input variable for the neural network model at lags 3 days and 11 days respectively. When two input variables are used to train the network, the combination of ST and PSM; and SR (solar radiation) and ST at lags 3 days and 6 days show better performance.

Swine effluent (SE) is a valuable source of plant nutrients that can be used as irrigation supply, but nutrients distribution in soil profile under subsurface drip irrigation (SDI) is not well documented. We evaluated the impacts of SE application trough SDI on bermudagrass production and soil salinity. The average (2008–2015) annual amounts of effluent, N, P₂O₅, and K₂O applied were 58 mm ha^-1, 88.5, 78.5, and 20.2 kg ha^-1, respectively. Nutrients distribution was uninform, evidenced by bermudagrass height and nutrient levels with respect to the distance to the drip tapes. Soil N, P, and K concentrations were higher above the drip tape, with major differences found along the soil profile and not between drip tapes. Sodium and EC were higher at the depth of the drip tape, but P, NO₃^-, and soluble salts did not accumulate to an excessive level. Although SDI was efficient in distributing nutrients, the uniformity was less than ideal.

The objective of the present study is to compare different sampling methods in controlled conditions in order to assess which is the most suitable for monitoring bioaerosols and dispersion. Different active sampling techniques were used and their performance assessed at different sampling times: impingement (AGI-4 and SKC BioSampler), filtration (glass fiber filters), and real-time viable particle counter (BioTrak). Two tracers were evaluated, a fluorescent tracer (ABF) and Escherichia coli (E. coli), added to the water. The results showed that the physical collection efficiency of AGI-4 when using ABF, was higher than SKC BioSampler. The sampling time influenced the culturability of E. coli collected by two impingers: with increasing sampling time from 5 min to 15 min, the culturability of E. coli collected by SKC Biosampler and AGI-4 decreased by 14% and 37%, respectively. By comparing the amount of collected E. coli with impingers and those counted by BioTrak, it appears that BioTrak provided a rapid but less accurate number of viable particles.

Water scarcity and water quality issues across the country are increasing the demand and acceptance by consumers for the use of recycled water. Recycled water is used for landscape irrigation, mostly for golf courses, but also for schoolyards, parks, athletic fields, cemeteries, nurseries, roadside vegetation, and some residential areas. There are no federal regulations regarding reuse but beginning in 1980 the EPA has published guidelines on reuse, which they upgrade every 12 years. The latest EPA guidelines were published in 2012. States in arid regions like California and Arizona, and states in areas with water supply issues like Florida have regulations on reuse. This paper will highlight the new 2019 Water Action Plan initiated by the EPA.

A greenhouse study was conducted to investigate the effects of irrigating with different levels of water salinities followed by freshwater application on soil profile salinity and chemical properties under Bermudagrass. Irrigating with saline water increased soil extract electrical conductivity (EC_e) at all layers, but the impact was significantly larger for the top 5 cm of the soil. The application of freshwater at the end of the experiment significantly reduced EC_e, especially for topsoil. Soil sodicity was not impacted, mainly due to the combination of salts selected for reaching the target salinity levels of irrigation water. Soil acidity increased with irrigation water salinity, but the application of freshwater did not have any impact on changing pH levels. The changes in concentrations of four major cations (sodium, calcium, potassium, and magnesium) were similar to those observed for EC_e.

Estimation of urban outdoor water demand is challenging due to variability in the irrigation of heterogeneous vegetated surfaces. Urban shade can cause fluctuations in irrigation water demand due to changes in air temperature subsequently affecting evapotranspiration (ET). This study analyzes the effect of urban shade on landscape ET. The shade is quantified using the sky view factor (SVF) whereas ET data from the Earth Engine Evapotranspiration Flux (EEFLUX) database is used. This analysis is done for May 2018 month that corresponds to hot season. A small region in Las Vegas Valley having varied land cover types is chosen for this analysis. This research reveals that the presence of shade decreases ET, potentially due to the decrease in air temperature and direct solar radiation. This study is insightful in understanding the effect of shade on irrigation water demand due to the presence of buildings.

Magnetic flow meters have become common meters for closed pipeline flow measurement due to their accuracy and non-invasive measurement. In the past, magnetic flow meters have been difficult to install (particularly in existing sites) due to straight pipe requirements upstream and downstream of the meter. The testing in this project was performed to quantify the effect various conditions have on the accuracy of several magnetic flow meters. Six models from six manufacturers in 4” and 10” sizes (12 meters total) were tested. Testing found about half of the meters had a baseline error (no obstructions upstream or downstream) of less than ±2%. Conditions found to have a significant effect for a majority or all the meters: double elbows directly (2D) upstream of a meter reduced accuracy; throttling a butterfly valve upstream of a meter by more than 50% reduced accuracy. Conditions found to have minimal or no obvious effect for most or all meters: obstructing the flow upstream in two planes, rather than one plane; electrical grounding of the meter. The results presented in this report are preliminary and subject to revision.

Currently, approximately 1,000 people per day move to Florida and based on 2035 demand, the Central Florida Water Initiative projects the resulting regional deficit will be 250 million gallons per day. New residential landscapes are often installed on compacted (bulk densities > 1.60 g/cm³), low-quality fill material with limited water holding capacity and nutrients. Incorporating organic amendments has been shown to mitigate compaction and improve soil quality. The goal of this study was to reduce landscape irrigation to new residential lawns and assess any water quality impacts of amending soils. This study was located in central Florida (Ocala) in the landscapes of 24 homes within an active adult community. Homes were constructed between 2017 and 2019. Data collection began during summer 2018 and will run through the end of 2020. Before landscape installation, one of three treatments [compacted (null), tilled, tilled with compost amendment] were applied just before empire zoysia turfgrass was installed. Soil moisture sensors were installed in 12 of the 24 homes to record volumetric water content within the top six inches. Lysimeters were installed in the backyards of all the homes to collect leachate to evaluate potential nutrient leachate to groundwater. Storm drains were instrumented with weir boxes, water level loggers, and autosamplers to measure and sample runoff. Water quality samples were analyzed for nitrogen species and phosphorus. Results from this study will be used to inform local government development and water resource policies.

Accurate flow measurement is critical for modern water resource management. At the irrigation district level, instantaneous flow rates must be well-measured at key bifurcation points to reliably meet downstream demand in open channel systems while also minimizing diversions. Furthermore, good flow measurement at each delivery point is a pre-requisite for successful volumetric water billing. Accuracy and repeatability are important characteristics of good flow measurement. Maximizing these traits requires periodic calibration to a common standard. This paper presents an overview of calibration efforts and the engineering background behind an active flow measurement facility at the Irrigation Training and Research Center at California Polytechnic State University, San Luis Obispo (Cal Poly). The facility is fitted with two major flow measurement devices, a gravimetric weighing tank and a volumetric tank. Although both are used for comparison, verification, and calibration of closed pipe and open channel flow measurement devices, this report will focus on an uncertainty analysis for the gravimetric weighing tank.

To increase the availability of suitable water supplies, reclaimed water can be stored in holding ponds prior to application. However, eutrophication can occur in holding ponds due to the high nutrient (e.g., nitrogen) concentration of reclaimed water. This can lead to frequent clogging of irrigation system filters due to the growth of algae in holding ponds. A promising solution may involve the use of wood chip biofilters for treating reclaimed water detained in holding ponds. Wood chip biofilters are known to provide a surface for microbial attachment and serve as a source of organic carbon to facilitate nitrogen removal via denitrification. The objective of this presentation is to describe the results from a preliminary microcosm study that mimicked a wood chip biofilter treating wastewater effluent and discharging the biofilter effluent into a holding pond. The results indicate lower holding pond nitrate concentrations when wood chip biofilter effluent is discharged into the holding pond compared to the control. Previous studies reported that nitrate removal only occurs in wood chip biofilters. However, the results from this study indicate the biofilter effluent itself can be used to enhance nitrate removal in holding ponds. This would lead to a reduction of algae in holding ponds, and subsequently, fewer solids build up in irrigation filters. Furthermore, if the nitrate removal performance of holding ponds also increases, then the design sizing requirement of wood chip biofilters would be reduced. This would facilitate the practical application of wood chip biofilter holding pond treatment systems.

Wastewater reuse was stared in Delaware in the 1960s when the food processing companies Clifton Canning, Wheatley Foods, Cannon Foods, and American Original using spray irrigation. They all applied the wastewater to reed canary grass or other types of grasses. Cannon Foods pastured beef cattle on their site. In 1970s Townsend started using spray irrigation on corn for their wastewater from their poultry processing plant. The Townsend Company was sold in 2002 to Mountaire Farms. Today they apply wastewater to corn and soybeans on approximately 1,000 ac. Spray irrigation was proposed for the resort towns of Rehoboth Beach and Lewis in the 1970s and for the town of Bridgeville in the 1980s. Both proposed projects were abandoned because of strong public opposition. In the 1990s three systems in the Inland Bays watershed and Water Farm #1 were constructed and began operation. In 2002 the town of Middletown started using spray irrigation. Today there is a great interest in rapid infiltration systems (RIBs) in Delaware. The first wastewater reuse project in Maryland began the 1940s when millions of gallons treated water from Baltimore City's Back River wastewater treatment plant were diverted daily to the Bethlehem Steel plant to be reused for industrial purposes before being discharged into the Patapsco River. The three dominant types of reuse in Maryland today are for irrigation (55%), cooling water (34%), and groundwater recharge (13%).

The Colorado River Basin supports agricultural, municipal, industrial, and environmental uses in seven states in the United States and in Mexico. This highly overallocated basin faces significant challenges in managing water and environmental resources under a complex set of compacts, federal laws, court decisions, decrees, contracts, and regulatory guidelines know collectively as the “Law of the River”. This paper highlights several key physical and institutional challenges facing the basin and summarizes the existing institutional processes in place for governance and decision making. The discussion encourages a more holistic approach to management of the Colorado River by integrating management and decision-making from the current program-specific management approach.

Modifications in land use and occupation, caused mainly by anthropization in both urban and rural regions, alter processes in the hydrological cycle. Such changes to watershed often lead to conflicts regarding the multiple water uses, due to issues in water quantity or quality. Mathematical models are a useful tool in determining and foreseeing such conflicts, as well as analyzing potential solutions and compromises to them. Among those, process-oriented simulation models can predict different behaviours undertaken by water throughout distinct media, enabling a comprehensive view on the watershed. This article describes the development of a generic aggregated hydrological model in a programming environment, coupled with an empirical buildup/washoff model. These models were then implemented in a region of the Alto Paranapanema watershed, in the state of São Paulo, Brazil.

Developing robust reservoir operation policies under uncertainty is becoming a more important topic due to climate change, severe droughts, and increasing water demands. Deterministic hydrologic models do not always provide an adequate range of possible outcomes to consider for robust operating schemes. In this study, one Istanbul reservoir located on European continents is modelled within the GoldSim dynamic simulation environment to develop risk-based operating rules. The model produces stochastic climate time series generated by the National Weather Service’s Weather Generator (WGEN), which feeds a runoff model to generate probabilistic inflow forecasts to the reservoir models. The reservoir models use operating criteria to evaluate the risk of supply shortages and over topping the spillway. The risk of exceeding operating criteria is measured and used to dynamically update operating controls to reduce risk.

In this study the reservoir capacity and sediment deposition was estimated using remote sensing data. The satellite images was synchronized with water level and storage capacity to find out the change in sediment deposition due to soil erosion and transport by stream flow. The water bodies spread area was estimated using vegetation indices, e.g., normalize differences vegetation index (NDVI) and normalize differences water index (NDWI). The 3D reservoir bathymetry was modeled by integrated water level, storage capacity, and area. From the models of different time span, the change in reservoir storage capacity was estimated. Another reservoir with known water level, storage capacity, area, and sediment deposition was used to validate the estimation technique. The t-test was used to assess the results between observed and estimated reservoir capacity and sediment deposition.

Naturalized flow, which is streamflow representing natural hydrology, is one of the hydrologic input datasets for Texas’ water availability models (WAMs) that are used for the water rights permitting process, regional and statewide water planning, and other water management activities in Texas. The existing naturalized flow input for most of these models covers the period extending from the 1940s to the 1990s. Given that some river basins in Texas have, in recent years, experienced record low streamflow associated with the 2010—2015 drought event, having updated naturalized flows is essential for reliable estimates of water availability from surface water sources. We find that for some river basins, or some part of a river basin, naturalized flows have a close correlation with observed flows. Furthermore, monthly naturalized flow in upstream watersheds and downstream watersheds, and vice versa, are also correlated, since streamflow under natural condition typically increases gradually downstream. Adjacent watersheds may also have similar flow characteristics. Therefore, it is relatively easy and fast to extend the WAM’s naturalized flow input using a regression method. We introduce a simple and convenient methodology for updating naturalized flows using linear regression between historical gauged flow and existing naturalized flow, between upstream and downstream naturalized flow, and between naturalized flow in adjacent watersheds. Naturalized flows updated using this methodology can be used as an auxiliary dataset for water planning purposes until the Texas Commission on Environmental Quality (TCEQ) releases official updated naturalized flow datasets for the state. We present an evaluation of the extended naturalized flows for the Canadian River Basin WAM and Sulphur River Basin WAM where the datasets used to develop the regression equations are highly correlated (correlation coefficient, R>0.93 and standard error <0.12). A comparison of extended naturalized flows for the Sulphur River Basin WAM derived using our methodology with the recently-released official update to the Sulphur River Basin WAM indicates that the average monthly mean flow is only 0.3% higher than the official average at a selected control point (i.e., model node). Simulated firm yield and overall water right reliability are within 2% of the same metrics derived using the official dataset. This result provides a validation of our dataset and justification for using such extended naturalized flows as auxiliary datasets for research and surface water resources planning in Texas.

The Grande River Basin accounts for 8% of total Brazilian installed electricity generation capacity, or 7,800 MW. Regarding conflicts over the use of water resources in this river basin, 35 conflict situations were identified and reported, which concern: pollution of water bodies by the discharge of sanitary sewage; diffuse pollution from agriculture and livestock; high uptake for irrigation; groundwater overexploitation in urban areas; among others. The Grande River Basin is in the southeastern region of Brazil, in the Paraná River Basin region which, together with the Paraguay and Uruguay river basins, form La Plata Basin. It is a watershed of significant territorial area, with more than 143,000 km². With a population of nine million, the Grande River Basin is made up of 393 municipalities, 325 have an area entirely included in the basin, which proves its greatness as a watershed that includes two important Brazilian states: Minas Gerais, to the north, with 60.2% of the drainage area of the basin, and São Paulo, to the south, with 39.8% of the area. Fifteen hydropower plants, constructed between 1960 and 2002, are present along this river basin. This paper details changes in governance of hydropower plants reservoir levels, used for regularization of inflows, along period between years of 2008 and 2018, in order to analyze limits to energy generation, imposed by increasing consumptive uses of water.

The Brazilian interconnected power system consists of a linked network of over 150 medium and large reservoirs, and a large set of small hydropower, thermal, and wind power plants. Hydropower has been the predominant source of electrical energy supply in Brazil, with significant increasing participation share of run-of-river hydropower, and thermal and wind power plants. In this paper we modify the HIDROTERM, a nonlinear programming optimization model previously developed for planning the operation of the Brazilian hydrothermal system. First, we modify the storage constraints at the end of the planning horizon based not only on individual storage at each reservoir, but also consider the stored energy in each subsystem. Additionally, we penalize unnecessary spills and reward storage savings over the minimum requirements. The first modification increases the feasible region in the decision space, while the second modification is directly included in the objective function. These modifications were tested with different hydrological scenarios and initial conditions of the hydropower system. The modifications have resulted several benefits, including a greater flexibility to storage water in the multiple reservoir system, reduction of infeasibilities under more severe drought scenarios, increased productivity in some cascade reservoir systems with reduction in thermal dispatch and operational costs, and increased water savings at the end of the planning horizon.

The vast majority of the available water supplies in Colorado are still associated with irrigated agriculture, while the state’s population is growing at a very fast rate, creating an ever-increasing demand for municipal water supplies. Since irrigated agriculture represents a significant part of the state’s economy it is unwise to remove irrigation water from agricultural uses to serve growing municipal demands, i.e., the concept of “buy and dry” of irrigated lands. The Parker Water and Sanitation District (“PWSD”), a quasi-municipal water provider, and the Lower South Platte Water Conservancy District (“LSPWCD”), serving a principally-agricultural area, have joined forces to develop a very innovative means to sustain historic agricultural irrigation practices while, at the same time, providing much-needed municipal water supplies to assure a sustainable water supply for the future of PWSD’s customers, as well as potentially other municipal water suppliers along Colorado’s Front Range. This water development plan may become the template for future water supply development to meet the needs of both major economic sectors in Colorado.

This paper aims to show how the integration between weather radar and rain gages is used to improve landslide forecast in the megacity of São Paulo. The city of São Paulo is one of the biggest city in the world. However, this megacity has a chronic landslide problem that occurs every year, especially during the summer. Structural measures for landslide control are extremely expensive and not possible to be built in short term. In this scenario, non-structural measures such as a warning system is an alternative measure. This system aims to provide real-time occurrence and forecast of landslide that may cause impacts in several areas of the city. The city of São Paulo has more than 400 areas with high and very high landslide susceptibility. The accuracy of landslide forecast in real time is extremely important for a good result. Precipitation is the main forcing in this process and must be estimated properly. Rain gauge networks can represent rainfall locally but has a bad spatial representativeness. Weather radars provide very high spatial resolution but not so good accuracy for rainfall intensity. The integration of radar estimations with rain gauge network is capable to minimize errors of both. The goal of this work is to present a methodology to merge weather radar estimates with rain gauge network to calculate the rainfall accumulation over the risk areas. For the integration, it was used São Paulo weather radar and the rain gauge network from São Paulo Flood Warning System.

The metropolitan region of São Paulo (MRSP) suffered a record-breaking drought period between 2013 and 2018. With 21.5 million inhabitants, the region has one of the largest water supply systems in the world, consisting of ten partially interlinked reservoir systems. A set of mitigation measures and expansion works were adopted during the last few years to recover from the recent drought and improve reliability and resilience of water supply. For example, the newly built São Lourenço water supply system is comprised of catchment structures, pumping stations, a water main, and water treatment plant (WTP). This system is able to supply water to approximately two million people and plays a complementary but important role in increasing water security in MRSP. While the system competes with energy production in a highly productive hydropower cascade, it has an installed capacity of 6 m³/s, head near 400 m, and a 50 km long water main (its diameter is equal to 2,100 mm). Permitted average water withdrawal is 4.7 m³/s. Other features of this system are three raw water tanks at the entrance of WTP, with a volume of 25,000 m³ each, which helps to minimize pumping during peak hours. This paper studies linear and mixed integer programming applied to optimize the short-term pump scheduling and raw water tanks operation of the São Lourenço system, considering peak and off-peak prices of energy, variation of demand, cleaning and maintenance services, and stops/starts constraints.

The Yangtze River Basin has a huge amount of sediment transport and plays an important strategic role in China’s social and economic development. In recent years, the time-space distribution of the sediment in the Yangtze River Basin and the process of production and transportation have changed greatly. The contradiction between supply and demand of the sediment resources is becoming more and more serious. This paper summarizes the main ways of utilization of sediment resources in the Yangtze River Basin, and analyzes the new situation of sediment transport and sediment redistribution in the Yangtze River Basin. In order to alleviate the contradiction between sediment supply and demand in the Yangtze River, it is necessary to strengthen the combined water and sediment operation in the upper reaches of the Yangtze River to optimize the allocation of water and sediment resources, improve the uneven distribution of sediment from a macro level, and carry out sand excavation and silting in the upstream reservoirs to make full use of the sediment resources of the reservoir. We should strengthen the management and planning of sand mining in river courses, make rational use of sediment resources in tributaries and lakes, reduce the pressure of sediment demand in the main stream of the Yangtze River, and actively promote the comprehensive utilization of dredged sand in the channel of the Yangtze River.