Peter Dillon

A simple method using farmers’ measurements applied to estimate check dam recharge in Rajasthan, India

Since the 1960s more than 200,000 check dams have been constructed on ephemeral streams in India to enhance groundwater recharge and help sustain irrigation supplies. While many farmers, non-government- and government organizations attest to check dam effectiveness, very few (<30) have been quantitatively evaluated and results have been variable. The paper describes the application of a simple daily water balance calculation to four check dams near Udaipur in southern Rajasthan where farmers took daily measurements of check dam water levels and rainfall for 2 years. The farmer measurements were proven to be highly reliable. They revealed that the check dams augmented recharge by 33xa0mm in 2014, an “average” year, and by 17xa0mm in 2015, a “dry” year (where recharge is expressed as depth over the combined catchment area of the check dams). This corresponded to 2.0 and 1.0 times the combined capacity of these check dams in those years, and the average annual recharge volume, 743,000xa0m3, supports 16% of agricultural production in the rabi (winter) season from the surrounding villages. Total recharge was estimated to be 37% and 70% of combined runoff in 2014 and 2015, respectively. Mean dry weather infiltration rates averaged from the four sites over both years were 5–8 times the evaporation rate from check dams. Hence, based on farmer measurements, it is conclusive that the studied check dams are effective and efficient in recharging the local aquifer. The paper demonstrates that a simple method can be used by farmers with basic training to determine the need for desilting of check dams in the following dry season and to provide essential data to allow quantification of recharge from check dams. This opens the possibility of scaling up by orders of magnitude the number of check dams evaluated. With more check dams monitored over longer periods, quantitative data would become available to inform on sizing and placement of check dams in relation to local benefits, capital and maintenance costs and downstream impacts, and thereby to inform future investment in check dams.

Water Harvesting Potential of WSUD Approaches

Abstract This chapter provides an introduction to the role of stormwater and roofwater harvesting for beneficial use as part of an integrated water sensitive urban design approach to urban development. Stormwater harvesting provides a useful alternative water source as well as significant stormwater management benefits by reducing runoff volumes and the associated pollutants. The different types of harvesting and potential uses for the water are discussed, as are the important design considerations to be addressed in developing a successful scheme. Analytical tools for assessing potential stormwater yield are identified. Other related issues that may affect scheme development are discussed, including water treatment, validation and verification, and jurisdictional and governance issues.

Advances in multi-stage planning and implementing managed aquifer recharge for integrated water management

Managed aquifer recharge (MAR) is the umbrella term for a range of technologies that enable the integrated use and management of surface water and groundwater to achieve a wide and growing range of social, economic and environmental benefits. The extent and variety of its applications and benefits have mushroomed in recent years as demonstrated in the suite of papers contained within this Special Issue of Sustainable Water Resources Management. This paper introduces the Special Issue and draws together some insights arising from the findings of these papers. Managed aquifer recharge projects normally evolve through a development cycle that covers planning, investigations, pilot scale trials and then implementation of full-scale projects. This Special Issue starts with four papers that synthesize information from a large number of MAR sites, to demonstrate the scope and geographic distribution of international efforts in MAR, factors affecting the economics of MAR projects, and efforts to find metrics to compare their performance among sites and over time. Then there are four papers describing some significant and widely contrasting completed MAR projects in four continents covering their development, what has been learned and some operational issues. Given this context, the next five papers explore the implementation and evaluation of pilot projects in three countries. These papers address issues ranging from hydrogeological characterization, evaluating impacts on groundwater-dependent ecosystems to community participation. All papers to this point give context to the final five papers that show the planning and preliminary studies performed to select MAR sites, to design pilot projects or to explore the feasibility of large-scale MAR programs. Arranging the sequence of papers in this way is intended to yield an understanding of the need for the investigations and modelling to produce viable projects, and to help readers to consider some important practical questions. What steps are needed for any given project to: define objectives; build partnerships; engage with communities; assemble evidence of technical viability, sustainability and safety; secure funding; design and construct efficiently; streamline operations; and finally to monitor the extent to which a completed project met its goals? These papers were developed out of a broader selection of papers presented at the 9th International Symposium on Managed Aquifer Recharge (ISMAR9), Mexico City, June 2016. They are a companion to another Special Issue arising from ISMAR9, published in the journal Water on the complementary theme “Water Quality Considerations for Managed Aquifer Recharge Systems” edited by Prof. Dr. Pieter Stuyfzand and Dr. Niels Hartog (2017). These Issues are a contribution of the International Association of Hydrogeologists Commission on Managing Aquifer Recharge (IAH-MAR) to the advancement and dissemination of knowledge for wise application of MAR.

Sixty years of global progress in managed aquifer recharge

The last 60xa0years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10xa0km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies.AbstractIn den letzten 60 Jahren gab es sowohl eine beispiellose Grundwasserentnahme und Übernutzung als auch die Entwicklung neuer Wasseraufbereitungstechnologien, was die gezielte Grundwasseranreicherung (GWA, auch managed aquifer recharge, MAR) vorantreibt. Dieser Artikel ist der erste bekannte Versuch, den Umfang der GWA im globalen Maßstab zu quantifizieren, Fortschritte bei den drei Haupttypen der GWA zu veranschaulichen und diese in Beziehung zur Forschung und zur Entwicklung behördlicher Regelungen zu stellen. Angesichts des Klimawandels und einer zunehmenden Intensität der Klimaextreme ist die GWA eine zunehmend an Bedeutung gewinnende Wasserbewirtschaftungsstrategie, neben dem Verbrauchsmanagement, der Erhaltung, Pflege und Sicherung von Grundwasserressourcen und dem Schutz und der Verbesserung der Wasserqualität. In dieser Zeit bildete die wissenschaftliche Forschung zur hydraulischen Anlagenauslegung, zu Tracerversuchen, zum Kolmations-Management, zur Effizienz der Wasserrückgewinnung und zu Wasserbeschaffenheitsänderungen in Grundwasserleitern die Basis für die praktischen Fortschritte in der GWA, mit weiterem Nutzen für die Hydrogeologie. Infiltrationsbrunnen haben die GWA stark beschleunigt, insbesondere in urbanen Gebieten und im bergbaulichen Wassermanagement. In jüngster Vergangenheit wurde zu Führungsstrukturen, Betriebspraktiken, Zuverlässigkeit, Wirtschaftlichkeit, Risikobewertung und gesellschaftlicher Akzeptanz geforscht. Seit den 1960er Jahren ist die Anwendung der GWA um 5% jährlich gestiegen, hält jedoch mit der steigenden Grundwasserentnahme nicht mit. Zur Zeit hat die GWA einen Umfang von geschätzt 10xa0km3/a, ~2.4% der Grundwasserentnahme in Ländern mit GWA-Nutzung (oder ~1.0% der weltweiten Grundwasserentnahme). Gemäß Erfahrungen in Gebieten, in denen die GWA bereits fortgeschritten ist, wird die GWA voraussichtlich 10% der globalen Entnahme überschreiten, um die Quantität, Zuverlässigkeit und Qualität der Wasserversorgung zu sichern.RésuméLes 60 dernières années ont vu l’extraction et la surexploitation des eaux souterraines sans précédent, ainsi que le développement de nouvelles technologies pour le traitement de l’eau qui, ensemble, permettent une avancée dans la recharge intentionnelle des eaux souterraines, connue sous le nom de recharge maîtrisée des aquifères (MAR). Cet article est la première tentative connue de quantification du volume de MAR à l’échelle mondiale, et d’illustration de l’avancée de tous les principaux types de MAR et qui fait le lien avec la recherche et les avancées en matière de réglementation. Face à l’évolution du climat et à l’intensité croissante des phénomènes climatiques extrêmes, MAR est une stratégie de gestion de l’eau de plus en plus importante, à côté de la gestion de la demande, pour maintenir, améliorer et sécuriser les systèmes hydrogéologiques sous stress hydrique et pour protéger et améliorer la qualité de l’eau. Au cours de cette période, la recherche scientifique, sur la conception hydraulique des installations, les études de traçage, la gestion des colmatages, l’efficacité de la récupération et les changements de la qualité de l’eau dans les aquifères, a soutenu les améliorations pratiques de MAR et a été plus que bénéfique de manière générale pour l’hydrogéologie. Les puits de recharge ont considérablement accéléré la recharge, en particulier dans les zones urbaines et pour la gestion des eaux de mine. Ces dernières années, la recherche sur la gouvernance, les pratiques d’exploitation, la fiabilité, l’économie, l’évaluation des risques et l’acceptation par le public de MAR a été entreprise. Depuis les années 1960, la mise en œuvre de la MAR s’est. accélérée à un taux de 5% par an, mais elle n’est. pas en phase avec l’augmentation de l’exploitation des eaux souterraines. Actuellement, MAR a atteint environ 10xa0km3/an, soit environ 2.4% de l’exploitation des eaux souterraines dans les pays déclarant l’utilisation du MAR (ou ~1.0% de l’extraction mondiale des eaux souterraines). MAR est susceptible de dépasser 10% de l’extraction mondiale, basée sur l’expérience où MAR est plus développé, pour maintenir la quantité, la fiabilité et la qualité des approvisionnements en eau.ResumenEn los últimos 60 años se ha visto una extracción y un giro sin precedentes del agua subterránea, así como el desarrollo de nuevas tecnologías para el tratamiento del agua que en conjunto impulsan el avance en el reabastecimiento intencional de agua subterránea, conocido como gestión de la recarga de acuíferos (MAR). Este trabajo es el primer intento conocido para cuantificar el volumen de la MAR a escala global, y para ilustrar el avance de los principales tipos de MAR y relacionarlos con la investigación y los avances normativos. Frente a los cambios climáticos y la creciente intensidad de los extremos climáticos, MAR es una estrategia de gestión del agua cada vez más importante, junto con la gestión de la demanda, para mantener, mejorar y proteger los sistemas de aguas subterráneas, proteger y mejorar la calidad del agua. Durante este tiempo, la investigación científica sobre el diseño hidráulico de las instalaciones, los estudios de trazadores, la gestión de obstrucciones, la eficiencia de la recuperación y los cambios en la calidad del agua en acuíferos ha sustentado mejoras prácticas en la MAR y ha tenido beneficios amplios para la hidrogeología. Los pozos de recarga han acelerado enormemente la recarga, particularmente en áreas urbanas y para la gestión minera del agua. En los últimos años, se han llevado a cabo investigaciones sobre gobernanza, prácticas operativas, confiabilidad, economía, evaluación de riesgos y aceptación pública de la MAR. Desde la década de 1960, la implementación de la MAR se ha acelerado a una tasa de 5% por año, pero no está al mismo ritmo que el aumento de la extracción de agua subterránea. Actualmente, la MAR ha alcanzado un estimado de 10xa0km3/año, ~2.4% de la extracción de agua subterránea en los países que informan MAR (ó ~1.0% de la extracción mundial de aguas subterráneas). Es probable que MAR exceda el 10% de la extracción global, en base a la experiencia donde la MAR está más avanzada, para mantener la cantidad, confiabilidad y calidad del suministro de agua.الملخصشهدت ألـ 60 عاماً الماضية عمليات استخراج وسحب واستنزاف للمياه الجوفية لم يسبق لها مثيل ، فضلاً عن تطوير تكنولوجيا جديدة لتنقية ومعالجة المياه ، وهذا الوضع يُشجع التقدم في التجديد والتغذية المتعمدة للمياه الجوفية والمعروف بـ “التغذية المُتحكم فيها لطبقات المياه الجوفية (مار)”. هذه الورقة العلمية هي أول محاولة معروفة لتحديد حجم “مار” على نطاق عالمي ، ولتوضيح تقدم جميع الأنواع الرئيسية من “مار” وربطها بكلاً من التطور البحثي والتنظيمي. في مواجهة تغير المناخ وارتفاع كثافة تطرفات المناخ ، يعد “مار” إستراتيجية ذات أهمية متزايدة لإدارة المياه ، إلى جانب إدارة الطلب من المياه، للحفاظ وتعزيز أنظمة المياه الجوفية المجهدة وتعزيز وحماية جودة المياه وتحسينها. خلال هذا الوقت ، فإن البحث العلمي ، والتصميم الهيدروليكي للمرافق ، ودراسات التتبع ، وإدارة الانسداد ، وكفاءة الاستعادة ، وتغيرات جودة المياه في طبقات المياه الجوفية ، كل ذلك قد دعم أضاف تحسينات عملية في “مار” بالإضافة إلى فوائد أوسع في الهيدروجيولوجيا. وقد ساهمت آبار إعادة التغذية في تسريع عملية إعادة تجديد طبقات المياه الجوفية ، لا سيما في المناطق الحضرية وإدارة مياه المناجم. في السنوات الأخيرة قد تم القيام بإجراء بحوث في مجالات: الحوكمة ، ممارسات التشغيل ، والموثوقية ، الاقتصاد ، تقييم المخاطر ، القبول العام لطريقة “مار”. منذ ستينيات القرن العشرين ، تسارع تنفيذ طرق “مار” بمعدل 5% سنوياً ، لكن هذا لا يواكب زيادة استخراج المياه الجوفية. وحالياً وصل “مار” إلى ما يُقدر بنحو 10 كيلو متر مكعب /عام ، أي 2.4% من استخراج المياه الجوفية في الدول التي أبلغت عن استخدام “مار” (أي ما يعادل 1.0% من استخراج المياه الجوفية على مستوى العالم). من المرجّح أن يتجاوز معدل تجديد طبقات المياه الجوفية باستخدام طريقة “مار” بمقدار 10% من سحب المياه الجوفية علي مستوي العالم ، وذلك بناءاً على الخبرة في تقييم التقدم في تطبيق طرق “مار” للحفاظ على كمية وموثوقية وجودة إمدادات المياه.摘要在过去的60年,前所未有的地下水开采和超采以及水处理新技术的开发共同推动了有目的地下水补给的发展,称为可管理的含水层补给(MAR)。本文是首次尝试在全球范围内对可管理的含水层补给的量进行量化,并且阐述可管理的含水层补给的所有主要类型以及与其相关的研究和监管进展。面对气候变化和气候极端事件强度的加大,可管理的含水层补给是一项越来越重要的水管理战略,除了需求管理,还可以维持,改善及保护超采的地下水系统,而且还能提高水质。这段时间,对回灌设施的设计、示踪研究、堵塞管理、回收效率和含水层水质变化的科学研究支撑了可管理的含水层补给工程技术的改进,并丰富了水文地质学。特别是在城市地区和对矿井排水的管理,回灌井极大

Aspects of Water Quality Improvement during Aquifer Storage and Recovery

Aquifer storage and recovery is recognized in the USA as having a significant role for inter-season storage of drinking water, and in Europe and Australia also for its potential for water treatment. However a better knowledge of water quality changes during aquifer storage and recovery, along with better understanding of sustainable treatment processes in aquifers is necessary to enable water utilities to take advantage of this technique. The usefulness of aquifer storage and recovery to improve the quality of injected water is being investigated at several sites. Specific interest is on the attenuation rates of microbial pathogens and organic compounds (both natural and synthetic) in saturated groundwater at artificial recharge sites. Microbial pathogens of particular interest are enteric viruses and protozoa, while the organic chemicals being investigated include several disinfection-by-products and endocrine disruptors. The aim is to encapsulate the data obtained from this investigation into models for the prediction of changes in water quality, and which can be used by water utilities and regulators to evaluate pretreatment requirements for aquifer storage and recovery. This will also improve accuracy of information for the protection of the health of consumers and the environment.