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Since last few decades, the extensive underutilization has been found in canal irrigation. This issue constitutes the serious lacuna in irrigational planning which often depicts the major problem about optimal water use. As per FAO Aquastat 2015 records for India, out of 91% of water utilized for agriculture purpose, 45% is getting lost under different types of conveyance losses from dam headworks till farms. The conveyance losses constitute the seepage and evaporation losses. Out of these, seepage is a quite significant loss in most of the water conveyance systems. Estimating conveyance losses using physical methods is quite difficult and involves lots of field work and calculations, whereas empirical and analytical methods will not accommodate site condition of respective study area. This study attempted to assess the conveyance loss of Dudhganga Right Bank Main canal with the help of a hydraulic model built on a spatial platform and verified with flow-monitoring events. The hydrospatial model was simulated to understand the canal behaviour and evaluate the conveyance losses. The results show Dudhganga Right Bank Main canal has average 39.96% water conveyance loss.

The River Chenab is one of the main western rivers of the Indus River system in Pakistan, which undergoes intensive inundation almost every year during the late monsoon period. The present study performs flood frequency analyses for the river basin as well as simulates different levels of water flow in the system to speculate all kinds of inundation under different scenarios, i.e., to predict flood hazard and flood extended areas. Flood frequency analyses were performed at MARALA Headworks to Khanki Headworks. Data were collected from the Punjab Irrigation Department, Pakistan and from USGS and ASTER GDEM. The peak discharge of MARALA Headworks had been analyzed for 25 years. The preprocessing was performed in HEC Geo-RAS after preprocessing model run in HEC-RAS. After analysis the data were exported in HEC-RAS to ARCMAP to generate a floodplain and inundation map. Our analysis generated the result that different areas would be under water in different return periods. Flood hazards maps for different return periods 10, 20, 50 and 100 years were conducted using annual peaks flow of 35 years from 1980 to 2016. The maximum discharges at up and down stream for different periods were obtained using Gumbel distribution model results which showed that different areas were predicted under water in different return periods and affected areas after five years’ return period.

This study was carried out to evaluate the impact of untreated urban and industrial effluents on water quality of river Ravi. Water samples were collected from 11 polluted and relatively unpolluted sites at river Ravi during low flow season and analyzed for heavy metals content and physico-chemical parameters. Dissolved oxygen fell below the recommended limit for propagation of fish and other aquatic life as the river flows through Lahore up to Balloki Headworks. Manganese and lead contents were higher than permissible limits for aquatic ecosystems at several polluted sites of the river. Highest concentration of nickel, zinc, manganese, cadmium and lead detected in river water was 20.0 µg/L, 70.0 µg/L, 190.0 µg/L, 2.0 µg/L and 72.0 µg/L respectively. Findings revealed that river water at downstream sites of wastewater carrying drains was not suitable to support fish and other aquatic life due to its very low dissolved oxygen level.

In light of the direct entry of surface water by inundation during floods and extreme rainfall events into riverbank filtration (RBF) wells and the consequent risk of contamination, this study discusses the state of the art of sealing the borehole annulus and well headworks in some developing countries exemplified by northern India in context to established guidelines and standards. Accordingly a market survey was conducted and a concept was developed to construct watertight wellhead elements and a flood-proof well chamber. The concept was implemented through the fabrication of the major components of a watertight wellhead in India and the subsequent construction of watertight headworks and a flood-proof chamber for a RBF well in Srinagar (Uttarakhand, India). The study showed that water wells at risk of flooding in general can be made flood-proof. A novel concept of deliberately flooding the well chamber was tested and proved successful. Although the fabrication enterprises and suppliers of well construction material in India currently do not produce non-standardised or special purpose well components, experience from the current study shows that local small-medium enterprises engaged in the unorganized metal working sector possess the technical competence to fabricate some of the major components but in limited numbers. The familiarisation of water supply practitioners and the well construction industry in India on the need and measures to flood-proof wells must be continued through information and education campaigns.

The British Government of India divided the Muslim majority province of Punjab into Eastern and Western Punjab. But the partition line was drawn in a manner that headworks remained in India and irrigated land in Pakistan. The partition of Punjab was not scheduled in the original plan of the division of India. Why was it partitioned? To answer this question, the study in the first instance tries to explore circumstances, reasons, and conspiracies which led to the partition of Punjab which led to the division of the canal irrigation system and secondly, the impact of partition on water resource management in the Indus River Basin. Descriptive, historical, and analytical methods of research have been used to draw a conclusion. The study highlights the mindset of Indian National Congress to cripple down the newly emerging state of Pakistan that became a root cause of the partition of Punjab. The paper also highlights why India stopped water flowing into Pakistan on 1st April 1948 and the analysis also covers details about the agreement of 4th May 1948 and its consequences for Pakistan.

In a Run-of-River (ROR) hydropower project with a low height diversion structure, sediment build-up in front of a side intake and removal of deposit are always a challenge. The design of sluice gates and intake layout is based on subjective expert knowledge and always involves rigorous discussion. The layout and design are popularly investigated and optimized through physical hydraulic model tests, but fine sediment transport cannot be modelled due to scaling issues. Numerical 3D hydraulic models are developed to cope with this and are gaining increased attentions due to high speed and low costs. This paper presents the utilization of a numerical hydraulic model for study of an intake layout considering the sediment transport. A case study of design of headworks of Kabeli-A Hydroelectric Project in Nepal is presented. Physical hydraulic modelling of the headworks was conducted to select an alternative solution and to optimize the design of intake layout for efficient handling of sediment build-up at the front of the intake. The investigation only conducted modelling of bed load transport and effects of the suspended sediments were assumed. The sediment transport modelling in front of the intake was performed using a 3D RANS model coupled with a sediment transport module. Three alternative layouts of intake were studied. The fine sediment build-up is modelled successfully, providing the duration for the bed to reach the intake invert and the sediment concentration passing through the intake. The results of the numerical model were found to be similar with the results of the physical model investigations. It is concluded that a numerical model can be used to study and select a best layout of intakes for efficient handling of fine sediments.

Sunkoshi Small Hydropower Plant (SSHP) is a run-of-river type project constructed in Sunkoshi River located in Sindhupalchowk District of Bagmati zone of Central Development Region, Nepal. The plant started its commercial operation since March 2005. During the year 2014, 2015 and 2016 the plant faced series of natural disaster events; landslide at Jure village on 2 August 2014, earthquake (7.8 magnitude) on 25 April 2015, landslide dammed flood in Sunkoshi River on 11 August 2015 and Glacier Lake Outburst Flood (GLOF) in Sunkoshi River on 5 July 2016. The Jure landslide created 55 m dam across Sunkoshi River. Thus created landslide dammed lake inundated the powerhouse of SSHP for 36 days. About seven million cubic meters of water was reserved in the lake. The event damaged entire powerhouse building, Electromechanical Equipment (EM), tailrace culvert, portion of steel penstock pipe and staff quarter. The rehabilitation works after Jure landslides included strengthening of powerhouse building and tailrace culvert, winding of generators, replacement of electromechanical equipment and portion of penstock pipe and change of transmission line alignment. On 25 April 2015, most of the rehabilitation works were completed. The EM experts were conducting a wet test for power generation when the power-plant was hit by other natural disaster - earthquake of 7.8 Rector Scale. The earthquake and its aftershocks followed by landslide dammed outburst flood of 11 August 2015 damaged headworks structures - formed a cavern of 56.6 m3 below gravel trap, collapsed entire powerhouse building and damaged newly installed electromechanical equipment, created several landslides along water way alignment and damaged about 900 m of penstock alignment. Some innovations in designs were introduced such as construction of sliding type saddle supports, bio-engineering combined with civil engineering structures to stabilize landslides, retrofitting of powerhouse building, use of crackamite and rock drill and avoidance of heavy masonry wall and gable wall in powerhouse. After rehabilitation works, the power plant re-operated since 4 January 2016 - after about 18 months. However, the plant was again affected by a Glacier Lake Outburst Flood (GLOF) in Botekoshi River on 5 July 2016.

The results of author’s method for evaluation of water levels (and discharges) instability as the function of time are described and new Environmental Classification of water headworks is proposed, based on water flow velocity criterium and application the “instability factors” for determination save water levels elevations (and outlet works discharge conveyance capacity), accepted for design and valid for the whole project life period. The classification is based on the assumption, that local channel processes and risks (biological, erosion, sedimentation, ice control and other”s) within the environment of hydraulic works will be eliminated or negative impacts limited. The main aim of applied classification is to protect the hydrauulic water-head structures from degradation, aggradation and deterioration. The general specification for design of discharge capacity of spillways and outlet works determination are given, as well as the main principle of the investments management. The general and particular technical requirements are specified for mitigation the negative impacts on the hydraulic headwater structures, as well as structures influences on the environment.. The scope of required changes in regulations and specifications are given to include in the present polish regulations and standards, including European EC7 Standard.

The supply of safe drinking water in rural developing areas is still a matter of concern, especially if surface water, shallow wells, and wells with non-watertight headworks are sources for drinking water. Continuously changing raw water conditions, flood and extreme rainfall events, anthropogenic pollution, and lacking electricity supply in developing regions require new and adapted solutions to treat and render water safe for distribution. This paper presents the findings of a pilot test conducted in Uttarakhand, India, where a river bank filtration (RBF) well was combined with a solar-driven and online-monitored electro-chlorination system, treating fecal-contaminated Ganga River water. While the RBF well provided nearly turbidity- and pathogen-free water as well as buffered fluctuations in source water qualities, the electro-chlorination system provided disinfection based on the inline conversion of chloride to hypochlorous acid. The conducted sampling campaigns provided complete disinfection (&gt, 6.7 log) and the adequate supply of residual disinfectant (0.27 &plusmn, 0.17 mg/L). The system could be further optimized to local conditions and allows the supply of microbial-safe water for river bound communities, even during monsoon periods and under the low natural chloride regimes typical for this region.

This article is a case study for an energy savings performance contract (ESPC) at the wastewater treatment plant for the City of Riverbank in California. The existing plant has an average of 1.67 million gallons per day (MGD) flow and consists of the headworks, four treatment ponds, and seven percolation ponds. Prior to the project, the treatment ponds used surface aerators to provide oxygen for the biologic process. The plant was primarily operated manually with limited dissolved oxygen control. The utility bills showed excessive energy use—annual usage was 5,673 kWh/MG/yr. Schneider Electric and the City of River-bank entered into a construction contract to retrofit the treatment ponds with blowers and fine-bubble diffusers for more efficient oxygen transfer. Additionally, a control system was installed to maintain a dissolved oxygen set point. This scope of work is estimated to save 75% of the electricity consumption at the wastewater treatment plant and will save the city 65% of their electric...

The SHAFDAN is the largest wastewater treatment plant in Israel and currently treats 360,000 m3/day of municipal wastewater, about 92% of its treatment capacity. Waste sludge from the plant is discharged to the Mediterranean Sea through a marine outfall. The SHAFDAN is committed to ending the disposal of its sludge to the sea by the end of 2016 by providing a land-based biosolids management program that produces a Class A biosolids for agricultural use. In order to implement this strategy, a number of large-scale construction projects were undertaken. These projects include a new sludge thickening and dewatering facility, updated headworks, a new primary treatment facility, and a new 3-stage thermophilic anaerobic digestion facility. The total capital cost of these projects is estimated to be US $300 million. This paper describes the principal components of these projects and their design parameters.

Large numbers of perennial rivers flowing through steep gradient has made Nepal an ideal place for hydropower development. Development of hydropower project in most economical way possible is the first prerequisite to get maximum benefit from harnessing water resources. The maximum benefit can be achieved only through optimal design of the project. Each project component must be designed considering the required level of factor of safety, performance standards of each component and economy. On this backdrop, this paper intends to optimize the location of cutoffs in headworks to get maximum benefits from use of it in terms of safety and economy. Improper placement of cutoff not only reduces the factor of safety against piping but also curtails the project benefits due to excessive seepage flow. Piping (internal erosion of soil particles under structure) is associated with high exit gradient. It threatens the structural stability and ultimately leads to failure of structure while as excessive seepage flow limits the availability of flow for power generation and reduces the project benefits. So, the optimal design of headworks is an attempt to identify the best location of cutoff to control seepage flow and reduce exit gradient. Five different cases representing different location of cutoff were analyzed and their roles in controlling seepage flow and reducing exit gradient was evaluated to optimize the cutoff location. 2D Finite Element Method (FEM) was used for the seepage analysis. The analysis showed that cutoffs are essential to control seepage flow when dam/weir is founded in pervious soil. However, the best location to place cutoff must be adroitly identified to reap maximum benefit from use of cutoff. The analysis reveals that the role of central cutoff in controlling seepage flow and reducing exit gradient is very limited. Likewise, the u/s cutoff has minimum effect in reducing exit gradient but the d/s cutoff seemed very effective in reducing exit gradient resulting increased factor of safety against piping. Hence, this paper concludes that the d/s end is the optimal location to place cutoff to improve safety and economy of the project. In addition, the use of both u/s and d/s cutoffs extend positive roles both in controlling seepage flow and reducing exit gradient. However, in author’s opinion the construction cost of two cutoffs must be compared with benefit added by use of two cutoffs over use of single d/s cutoff. HYDRO Nepal Journal Journal of Water Energy and Environment Issue: 21, July, 2017 Page: 42-44 Upload Date: July 18, 2017

There is a serious concern regarding freshwater resources of Pakistan which have been mismanaged and now are depleting extensively due to other reasons like intensive application of agricultural pesticides and insecticides. The present study was conducted to determine the concentrations of cypermethrin, deltamethrin, permethrin, and bifenthrin in the samples of water, sediments, and fish collected from various locations of River Chenab, Pakistan, during summer and winter seasons. These locations include namely Marala, Khanki, Qadirabad, and Trimu Headworks. High-performance liquid chromatography (HPLC) was deployed for analysis and determination of pyrethroid concentrations in these samples. The analytics show the order of pyrethroid concentrations in river as fish> sediment>water. Whereas maximum concentrations of 0.472 μg g−1 found in fish and minimum concentrations were determined in water, i.e., 0.087 μg L−1 at the sampling locations of Trimu and Marala headworks, respectively. Moreover, highest mean concentrations of pyrethroid, i.e., 1.248 μg g−1 in fish were detected in winter season as compared to summers, i.e., 0.087 μg L−1. However, all the values of pyrethroid were found to be lower than the maximum permissible levels specified by EU and WHO-FAO. Whereas the levels of deltamethrin and permethrin in water were found much higher than the specific limits set by EU.

Grit is a nuisance material that causes abrasive wear to mechanical equipment increasing maintenance and operational costs while reducing equipment performance and useful life. Grit that is not captured in the headworks accumulates in processes throughout the plant, reducing capacity and detention time, and adversely influencing flow and circulation patterns 2 . Deposited grit must be manually removed, handled, hauled and disposed. Abrasive wear, process inefficiencies and basin cleaning operations increase treatment plant operating expenses. Choosing a grit removal technology has often been based on equipment price with little regard for device efficacy and consequent grit removal efficiency. The industry has lacked an unbiased side-by-side comparison of the currently available technologies. As a result, owners and engineers are forced to navigate a field of, what can be conflicting, performance claims made by various equipment manufacturers. This situation is perpetuated by the fact that there is no accepted, peer reviewed test standard for grit sampling and analysis. The purpose of this paper is to encapsulate various grit removal system performance data generated by a consistent and repeatable sampling and analysis methodology for the purpose of comparing virtually all grit removal technologies in terms of their effectiveness. Results determined with this sampling method corroborates with the operating history and performance at the tested plants with respect to grit removal, suggesting the accuracy of the test method 6. The data provides an unbiased side-by-side comparison of the actual performance of grit technologies based on a repeatable sampling and analysis methodology that owners and engineers can utilize to protect plants from deposition, abrasive wear and associated costs from this nuisance material.

This study aims to review previous studies and projects on hydropower generation using irrigation canals in Japan, and discusses their future perspectives. The Japanese agricultural sector uses around two thirds of the total water abstracted, which is channeled through dams, headworks, as well as 40,000 km of canal networks. Although such infrastructure would collectively have significant hydropower generation potential, it has attracted scant attention, due to the relatively low individual potential at each site. To effectively utilize such small and diffuse potentials, we would need to: (1) develop small waterwheels operable with small water heads and low flow rates; (2) develop techniques to identify suitable waterwheel sites within an existing canal system taking channel slopes and sidewall heights and seasonal variations in flow rates into consideration; (3) investigate the possibility of locally utilizing electricity on a micro-scale of a few kW, rather than selling it to the grid; and (4) modify the water management scheme where possible by, for instance, smoothing out flow rates across seasons and thus increasing the cost-effectiveness of power generation.

Estimation of flooding is indispensable for the design of hydraulic structures such as dams, especially when there are many potential small dam sites available, but no flow data is being measured at these sites. If stream gauging stations are present upstream and downstream of the proposed dam site, empirical relationships can be developed for the site. The equation development process becomes more difficult when lateral flow releases are considered at various locations in a river reach. This issue is addressed in the present study, in which empirical equations are developed for flood prediction in the upper reaches of the Chenab River, between Marala Headworks and Qadirabad Headworks. The purpose is to predict flood magnitudes within selected reaches of the Chenab River. The selected gauging stations are Marala Headworks, Alexandra Bridge, Khanki Headworks and Qadirabad Headworks. To develop the equations, a multiple nonlinear regression analysis is used. Average river and watershed slopes for four watersheds are extracted from a digital elevation model, using geographic information systems software. The developed peak flood equations for the region are tested with observed flood data, and results show that these equations estimate peak floods within an acceptable range of accuracy. The developed empirical equations are region-specific, so their application to other areas requires discretion. However, these equations can be used to approximate floods in other regions with similar climatic and physiographic characteristics.

Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system, where flows in the main canal are automatically controlled and secondary canals manually operated. The main canal headworks have been equipped with the SCADA system with proportional integral (PI) discharge controllers and the canal itself has been provided with self-regulating AVIS/AVIO downstream control gates for flow regulation in the canal. The secondary canals have manually operated sliding gates, which are opened or closed as per crop water requirements of the command area following a crop-based irrigations operation (CBIO) schedule under which they remain closed for one week after one or several weeks open, depending upon water needs. The flow in the main canal is then automatically adjusted according to the number of open or closed secondary offtakes. These operations result in fluctuating flows in the main canal and if not properly planned can cause serious implications for canal safety and its hydrodynamic performance. The PI discharge controllers regulate discharge releases to the canal in order to satisfy demands. The proper selection of PI coefficients ensures system safety and efficient water delivery. The operation of the secondary canals also plays a key role in defining the performance of the automatic operations. The planned opening and closure of a cluster of offtakes ensures safety of the self-regulating structures and stability of the flows in the main canal. In this paper various options have been tested using hydrodynamic modelling and we found some optimal values of PI coefficients and defined some rules for secondary canal operations to enhance the operational performance and sustainability of downstream-controlled irrigation canals.

This paper presents the application of a long-term streamflow forecasting model developed using artificial neural networks at a stream gauging station in the Awash River Basin, Ethiopia. The gauging station is located above the headworks of a large irrigation scheme called the Middle Awash Agricultural Development Enterprise (MAADE). Based on the forecasted streamflow time series and water requirements for irrigation and environmental purposes, appropriate agricultural water management strategies have been proposed for the irrigation scheme (MAADE). The water management strategies which were evaluated in this study are based on different scenarios of abstraction demands. These demands were formulated based on a range of options for agricultural development and change in MAADE. The scenarios evaluated were based on such factors as the existing planting patterns, changing planting dates, changing crop varieties and reducing the area under cultivation. An appropriate scenario of agricultural development was decided on the basis of the modified flows in the river vis-a-vis the trigger/threshold value established at the Melka Sedi stream gauging station. Considering all the scenarios, it is suggested that a 1–24% reduction in the area currently irrigated in the scheme will ensure a reliable supply of water to the scheme throughout the growing season and will provide sustainable environmental flow in the river.

The objective of the present study was to demonstrate the effect the environment's entitlement configuration has on the volume of water supplied to the environment, and the overall efficiency of the water supply system under the historic climatic sequence and climate change. The modelling work is undertaken using the REALM simulation package, with the results presented in case study form based on the Wimmera-Mallee system, outlining the changes in the total system water balance post-Wimmera Mallee Pipeline, changes in the environment's reliability of supply, and exceedance plots for environmental flows and headworks loss. The outcomes of this study demonstrate the need to consider the trade-offs between large entitlements of low reliability and small entitlements of high reliability as part of the system reconfiguration process, given the effect it has on total system efficiency, particularly in an uncertain climate future.

The last 12 years has seen extreme drought in western Victoria. This has impacted on the area in many ways, but none more so than in the provision of basic water supplies to people. To meet the challenge of drought, headworks storages have had to be operated at record low levels, severe water restrictions imposed, water carting programs established, alternative sources of water, and new technologies developed and used. Significant changes have also been made to the water supply infrastructure in the region, most notably the Northern-Mallee and Wimmera-Mallee Pipelines. This paper relates the story of how water resources were managed and bulk water was delivered to around 70,000 customers over a geographic spread of 62,000 km2, or about 30% of Victoria. Discussion on the social, environmental and economic impacts on the region are also provided.

The paper reviews the problems being faced by the Upper Chenab Canal (UCC) and reports on the existing conditions assessed during various site visits. The water availability in the River Chenab at the Marala Barrage has been analysed based on the previous 20 years of recorded data in order to explore possible options for remodelling this canal. The visit report indicated that the UCC is faced with numerous problems such as bank erosion, bed scouring, side embayment, inadequate freeboard, abnormal behaviour and the deterioration of old hydraulic structures. Deferred maintenance and lack of proper and timely monitoring seem to be the main factors in the continuation of these problems in the canal. The water requirements at the head of the canal have been worked out as 562 m3 s−1, nearly 20% higher than the present capacity (477 m3 s−1). The study shows that the required amount of water is available for more than 90 days during the peak demand at 80% reliability for irrigation, hydropower generation and inter-river transfer to the River Ravi upstream of Balloki headworks for feeding its offtaking channels. The analysis also shows that the existing canal section is insufficient to pass the required discharge and needs to be remodelled to meet the requirements. This can be achieved by revising the canal section using a comprehensive design approach best suited to the local conditions. Copyright © 2010 John Wiley & Sons, Ltd. RESUME Le document passe en revue les problemes rencontres par Upper Chenab Canal (UCC) et rend compte des conditions existantes evaluees lors des visites d'inspection. La disponibilite de l'eau dans la Riviere Chenab au Barrage de Marala a ete analysee sur la base des vingt dernieres annees de donnees pour explorer les options possibles pour le remodelage de ce canal. Les rapports d'inspection montrent que l'UCC est confrontee a de nombreux problemes tels que l'erosion des berges, sedimentation importante, recul et echancrure des berges, insuffisance des franc-bords, un comportement anormal et la deterioration des anciennes structures hydrauliques. Le defaut d'entretien et l'absence de surveillance adequate semblent etre les principaux facteurs explicatifs des defauts constates. Les besoins en eau a la tete du canal sont estimes a 562 m3 s−1, soit un excedent de pres de 20% par rapport a la capacite actuelle (477 m3 s−1). L'etude fait ressortir que la quantite d'eau necessaire est disponible pour plus de 90 jours au cours de la demande de pointe a 80% de fiabilite pour les differents usages que sont l'irrigation, la production hydroelectrique et un transfert inter-fleuve vers l'amont de la riviere Ravi Balloki. L'analyse montre egalement que la section du canal actuel est insuffisante pour passer le debit requis et doit etre remodele afin de satisfaire aux exigences. Ceci peut etre realise par la revision de la section de canal en utilisant une approche de conception adaptee aux conditions locales. Copyright © 2010 John Wiley & Sons, Ltd.

In Indonesia, water is public goods so it is necessary to control water allocation. Inequity of water allocation between water users is expanding largely, including irrigation as the largest user, while the density of headworks in the river are getting higher. Considering that water is limited, the practice of irrigation water allocation needs to be refined, from the traditional equity to volumetric equity. MEQAA (Model Equalisasi Alokasi Air/Equalization Model of Water Allocation) plays a role in determining water sharing between headworks in order to meet the maximum-equal K-factor in river. MEQAA-Generic is a calculation machine with: analog-deterministic dynamic model; network equation according to mass balance and linear optimization; independent-based system; sustainability-efficiency-equity constraints; Ms. Excel-VBA. The inputs are: scheme system, local inflow, and irrigation demand. The outputs are: K-factor, release and ecosystem quote. The model performance is identified by comparing the output to the class of K-factor based on treatment of water distribution. The model test is performed in an uncontrolled and complicated system in Kukusan Tanggek watershed with 24 headworks in Lombok river basin. As long as it is adequate for water sharing, MEQAA-G can always produce maximum-equal K-factor. The output model is used to operation control.

A recently completed $120-million headworks is helping Columbus, Ohio, make significant progress in reducing sewer overflows. The innovative facility includes what are believed to be the largest self-cleaning trench-type wet wells in the United States, selected because they reduce space requirements and costs, minimize odors and corrosion potential, and make the facility easier to operate and maintain.

Urban water supply headworks systems are usually designed to provide high security against drought. The best way to evaluate this security is to use Monte Carlo simulation which is computationally expensive. The advent of parallel computing technology in conjunction with genetic algorithms has made it practicable to optimize operation for drought security. Nonetheless, computation turnaround times remain long. This paper presents a simple heuristic called replicate compression to improve Monte Carlo efficiency. It exploits the well known concept of a critical period. In a high reliability system there should be few critical periods. Therefore, restricting simulation to such periods should bring about substantial savings in computational effort. It was found for problems where the objective function evaluation is only affected by what happens during critical periods, replicate compression provides an effective means for substantially reducing simulation effort. The case study involving a nine-reservoir urb...

An 8800 km pipeline is currently being constructed in western Victoria to replace 17,500 km of open channel system. This Wimmera Mallee Pipeline Project (WMPP) will provide reticulated water to 36 towns and about 6000 farms across an area of approximately 2 million hectares. With this pipeline will come vastly improved efficiencies in the supply of water, with an estimated water saving of 103,000 ML being returned to the environment, existing consumptive use, new development and for recreation. The main source of supply to the WMPP will be from the headworks system located in and around the Grampians National Park, with the northern (Mallee) area supplied direct from the River Murray. The Grampians headworks system consists of 11 storages, each with their own unique hydrologic, environmental and socioeconomic attributes. The number of storages and their range of attributes enable a degree of flexibility with regards to the future configuration and operation of the headworks systems to meet the var...

This paper derives the efficiency price patterns for a comprehensive spatial and dynamic model of conjunctive water use incorporating conveyance losses, canal return flows, and groundwater recharge. The first-best shadow price of surface water is composed of a charge for water that flows into the farm and differential credits for water that flows to other uses. The shadow prices can be used as the basis of water pricing schemes or for exchange rates to facilitate water trading. We show that farmers near the headworks use irrigation water in the optimal program, and only farmers more distant from the headworks extract groundwater. We also illustrate the possibility of reswitching in the sequence of resource use. It may be efficient for some farms to switch from one source to another and then switch back again, e.g. groundwater to surface water to groundwater.

The Dujiangyan Irrigation Scheme is located in the middle reach of the Mingjiang River in Sichuan Province. It was initiated by Li Bing, the governor of Shu Prefecture, in the Qin Dynasty in 256 BC. It is a great scheme with a long history of 2260 years in ancient China, and has been very well operated until today. The headworks of the Dujiangyan Irrigation Scheme are composed of three major parts, i.e. Dujiang Yuzui (fish mouth), Feishayan, and Baopingkou. Dujiang Yuzui is a diversion dam, dividing the Mingjiang River water into two rivers, the Outer River and the Inner River. Feishayan is a spillway used for removing sand and excess water from the Inner River into the Outer River during flood. Baopingkou is an intake of the irrigation system, which automatically controls for a steady flow. These three parts are combined as an organic and complete whole with multiple functions of diverting water, spilling flood, releasing sediment, silt sedimentation, and automatic control of irrigation water. The whole headworks are reasonably planned and ingeniously coordinated with obvious effectiveness. In particular, this scheme has successfully treated the silt problem, therefore the possibility of being damaged by silt sedimentation is to a great extent avoided, and thus it can continue to flourish. In addition, the system of yearly maintenance also has its specialty: the construction technique is easily mastered by farmers, and all the construction materials came from local places. Therefore, the Dujiangyan Irrigation Scheme can normally be operated generation after generation. The Dujiangyan Irrigation Scheme encapsulates the scientific intelligence and civilization of Chinese nationality, and it still plays a vital role in the economic, social, ecological and environmental benefits for Sichun Province nowadays. It is a model of harmonious coexistence between mankind and nature, and is also included as a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization (UNESCO) as the first water project in the world. Copyright © 2006 John Wiley & Sons, Ltd.

The Mekele Plateau, located in the semi-arid northern highland region of Ethiopia, is a drought-prone, highly degraded area. It has long been neglected by policymakers and thus recurring famine, widespread poverty, armed conflicts and mass outmigration have contributed to the near collapse of the farming systems and the livelihoods of the population. Traditional stream diversion irrigation has been practised in this area for several centuries. The systems of water management in particular may be considered inappropriate owing to the need for thriftiness in water use imposed by the local environment. The systems of headworks and canals are crude and wasteful on water. Recent interventions to improve the small-scale irrigation systems of the area have not been successful. Most interventions have preferred to introduce rainwater harvesting systems using micro-dams rather than trying to upgrade the traditional diversion schemes. Evaluation of irrigation structures in the field, interviews with key informants in government, analysis of documents and discussions with irrigators indicate that both the Ministry of Agriculture and SAERT-Commission's rainwater harvesting programmes have generally failed. The case of the most recent intervention by SAERT has failed because of myopic project planning, inadequate engineering studies, unsound designs, too short a time for implementation, and lack of full farmer involvement at different levels of project planning and implementation.

Simulation models in conjunction with synthetic multiple hydro-climate replicates provide the most realistic assessment of the performance of urban water supply headworks systems. However, optimization using such models is computationally very demanding. To appreciate the challenge, a simple case study system is presented. The system consists of one reservoir, has three decision variables to be optimized, and uses an objective function based on reservoir costs and economic penalties for water shortages. Enumeration revealed that the objective function surface has piecewise flat regions that arise from operating rule thresholds and the infrequent sampling of severe droughts. Two search methods capable of dealing with such flat regions, the genetic algorithm (GA) and the shuffled complex evolution (SCE) method, were investigated. For the GA to be robust (i.e., avoid premature convergence on flat regions), it was necessary to employ two lesser-known genetic operators, inversion and population selection strategy. The SCE method was found to have comparable robustness, but required fewer evaluations. Nonetheless, the GA method was preferred because of its inherent advantage in parallel computing.

The ascending route of the fish and the flow characteristics at the wall were demonstratively carried out in the ice-harbor type fishway (width: 2.6m, drop: 0.15m, pool-length: 3.0m, gradient: 1/20) of Akaishi the number 2 headworks on the Akaishi River in Aomori Prefecture. It was found that the swimming fishes swum up rectilinear for the flow in lower layer division (which the velocity was about 200cm/s) of disturbing overflow on the notches at the wall in the fishway canal. On the other hand, it was found that on the orifices of the wall in the fishway canal the fishes swum through in the each basal plane corner part as well as on the orifices of the uppermost stream division wall.

Source control measures include rainwater tanks, infiltration trenches, grassed swales, detention basins and constructed wetlands that can be used in housing allotments and subdivisions. A methodology for evaluating the regional economic benefits due to implementation of source control measures is presented and illustrated for two case studies in the Lower Hunter and Central Coast regions of New South Wales, Australia. It is demonstrated that use of rainwater tanks to supplement mains water supply for toilet, hot water and outdoor uses can very significantly reduce demand on mains water supply. Reductions in regional water demand will enable deferment of water supply headworks augmentation, while reductions in peak mains water demand will extend the life of water supply distribution infrastructure. In addition, substantial reduction of stormwater discharge from allotments can be realised. For the Lower Hunter region with an urban population of about 450,000 it is shown that construction of new water supply headworks infrastructure can be delayed by up to 34 years. Compared with the traditional provision of mains water and stormwater disposal, the use of rainwater tanks along with other source control measures can produce present worth savings to the Lower Hunter region conservatively estimated to be up to $67 million. Similar results were found for the Central Coast region.

The irrigation systems for the Red River Delta usually get water by pumping and gravity.The results determine the possible minimum water level line in the dry-season months under climate change scenarios (B2, SC5 and SC6 and current scenario is B2, SC4) on the river system of the Red River – Thai Binh River in study areas of project as below: Water levels on the Red River in the dry season under climate change scenarios significantly reduced compared with 2010. At Ha Noi station on Red River, the water levels reduce in 2050 about 6.5cm (B2) and 7.5cm (A2) and 6cm (B1). At Nam Dinh station on Dao River, the water levels reduce in 2050 about 4cm (B2) and 5cm (A2) and 3cm (B1). At Cat Khe on Thai Binh River, the water levels reduce in 2050 about 2cm (B2) and 3cm (A2) and 1.5cm (B1). At An Bai on Kinh Thay River, the water levels reduce in 2050 about 5cm (B2) and 6cm (A2) and 4cm (B1). At Truc Phuong on Ninh Co River, the water levels reduce in 2050 about 6.5cm (B2) and 7.2cm (A2) and 5.8cm (B1). In the scenario in which 50% of the socio-economic development plans are achieved (SC6), the water demand is lower than the scenario of full development (SC5). The decrease in the average water level in the whole Red River system is about 1.3-1.8 cm less than in SC5, and in Thai Binh river this figure is about 1.4-2.1cm. The lowering of the water level under climate change in the river has caused problems for irrigation during the dry season, in order to reach the target level in Hanoi.

The present study investigated the presence and potent source of pesticides and specific pesticide bearing effluent release points on the River Ravi, between the Shahdara and Balloki Headworks. Pakistan has banned the use of organochlorine and nitrogen containing pesticides, yet no attention has been paid to the continuous monitoring and assessment of these banned pesticides to make sure that they are not being used in practice. Levels of selected organochlorine and nitrogen containing pesticide residues were assessed in water collected from 18 sampling sites on the River Ravi and its tributaries using a gas chromatograph equipped with an electron capture detector (GC-ECD). All water samples were found to be contaminated with varying concentrations of pesticide residues. However, levels of pesticides were below the tolerance limits suggested in national and international standards. Pesticide concentrations in the water of river sites ranged from 0.034 to 0.045 microg/L for DDT, 0.033 to 0.046 microg/L for DDE, 0.108 to 0.123 microg/L for endosulfan and 0.028 to 0.040 microg/L for carbofuran. In tributaries, pesticide concentrations ranged from 0.0468 to 0.0685 microg/L for DDT, 0.0390 to 0.0637 microg/L for DDE, 0.111 to 0.147 microg/L for endosulfan and 0.0396 to 0.0631 microg/L for carbofuran. The results show pesticide concentrations in river water in the order: endosulfan > DDE > DDT > carbofuran. Pesticide concentrations in tributary waters decreased in the order: endosulfan > DDT> DDE > carbofuran. After Degh Fall and After Hudiara Nulla Fall river sampling sites were severely contaminated while, among the tributaries, Degh Fall and Hudiara Drain were severely contaminated with DDT, DDE, endosulfan and carbofuran. Constant monitoring programs should to be initiated to reform the present situation.