Mathematical models for the arrangement and the cleaning of the river basin and surroundings of the river sandy grounds to its passage by the city of Salta (Argentina)

The province of Salta is located the Northwest of Argentina in the border with Bolivia, Chile and Paraguay. Its Capital is the city of Salta that concentrates half of the inhabitants of the province and has grown to 600000 hab., from a small active Spanish town well founded in 1583. The city is crossed by the Arenales River descending from close mountains at North, source of water and end of sewers. But with actual growing it has become a focus of infection and of remarkable unhealthiness. It is necessary to undertake a plan for the recovery of the river, directed to the attainment of the well-being and to improve the life?s quality of the Community. The fundamental idea of the plan is to obtain an ordering of the river basin and an integral management of the channel and its surroundings, including the cleaning out. The improvement of the water?s quality, the healthiness of the surroundings and the improvement of the environment, must go hand by hand with the development of sport activities, of relaxation, tourism, establishment of breeding grounds, kitchen gardens, micro enterprises with clean production and other actions that contribute to their benefit by the society, that being a basic factor for their care and sustainable use. The present pollution is organic, chemical, industrial, domestic, due to the disposition of sweepings and sewer effluents that affects not only the flora and small fauna, destroying the biodiversity, but also to the health of people living in their margins. Within the plan it will be necessary to consider, besides hydric and environmental cleaning and the prevention of floods, the planning of the extraction of aggregates, the infrastructure and consolidation of margins works and the arrangement of all the river basin. It will be necessary to consider the public intervention at state, provincial and local level, and the private intervention. In the model it has been necessary to include the sub-model corresponding to the election of the entity to be the optimal instrument to reach the proposed objectives, giving an answer to the social, environmental and economic requirements. For that the authors have used multi-criteria decision methods to qualify and select alternatives, and for the programming of their implementation. In the model the authors have contemplated the short, average and long term actions. They conform a Paretooptimal alternative which secures the ordering, integral and suitable management of the basin of the Arenales River, focusing on its passage by the city of Salta.

A Landscape-based Regionalization of Natural Flow Regimes in the Ebro River Basin and its Biological Validation. River Research and Applications

Regionalización de tipos de régimen natural de caudales en la cuenca del Ebro y validación biológica de los tipos de regímen natural.

River Restoration in Spain: Theoretical and Practical Approach in the Context of the European Water Framework Directive.

River restoration is becoming a priority in many countries because of increasing the awareness of environmental degradation. In Europe, the EU Water Framework Directive (WFD) has significantly reinforced river restoration, encouraging the improvement of ecological status for water bodies. To fulfill the WFD requirements, the Spanish Ministry of the Environment developed in 2006 a National Strategy for River Restoration whose design and implementation are described in this paper. At the same time many restoration projects have been conducted, and sixty of them have been evaluated in terms of stated objectives and pressures and implemented restoration measures. Riparian vegetation enhancement, weir removal and fish passes were the most frequently implemented restoration measures, although the greatest pressures came from hydrologic alteration caused by flow regulation for irrigation purposes. Water deficits in quantity and quality associated with uncontrolled water demands seriously affect Mediterranean rivers and represent the main constraint to achieving good ecological status of Spanish rivers, most of them intensively regulated. Proper environmental allocation of in-stream flows would need deep restrictions in agricultural water use which seem to be of very difficult social acceptance. This situation highlights the need to integrate land-use and rural development policies with water resources and river management, and identifies additional difficulties in achieving the WFD objectives and good ecological status of rivers in Mediterranean countries.

Hydromorphic change and biotic response challenge efficient river rehabilitation

From an extensive literature review and meta-analyses, this study has i) identified the most important hydromorphological process related to river degradation and rehabilitation, ii) conceptually linked it to evolutionary and functional response chains of aquatic biota, and iii) provided empirical evidence and ecological data for the respective hydromorphological requirements, preferences and limitations of aquatic plants, benthic invertebrates, lampreys, and freshwater fishes.

The Interactive Effects of Temperature and Osmotic Potential on the Growth of Aquatic Isolates of Fusarium culmorum.

The mycelial growth of 10 Fusarium culmorum strains isolated from water of the Andarax riverbed in the provinces of Granada and Almeria in southeastern Spain was tested on potato-dextroseagar adjusted to different osmotic potentials with either KCl or NaCl (−1.50 to−144.54 bars) at 10◦C intervals ranging from15◦ to 35◦C. Fungal growth was determined by measuring colony diameter after 4 d of incubation. Mycelial growth was maximal at 25◦C. The quantity and capacity of mycelial growth of F. culmorum were similar at 15 and 25◦C, with maximal growth occurring at −13.79 bars water potential and a lack of growth at 35◦C. The effect of water potential was independent of salt composition. The general growth pattern of Fusarium culmorum growth declined at potentials below −13.79 bars. Fungal growth at 25◦C was always greater than growth at 15◦C, at all of the water potentials tested. Significant differences were observed in the response ofmycelia to water potential and temperature as main and interactive effects. The number of isolates that showed growth was increasingly inhibited as the water potential dropped, but some growth was still observable at −99.56 bars. These findings could indicate that F. culmorum strains isolated from water have a physiological mechanism that permits survival in environments with low water potential. Propagules of Fusarium culmorum are transported long distances by river water, which could explain the severity of diseases caused by F.culmorum on cereal plants irrigated with river water and its interaction under hydric stress ormoderate soil salinity. The observed differences in growth magnitude and capacity could indicate that the biological factors governing potential and actual growth are affected by osmotic potential in different ways.

Underground dwellings in the Tajuña valley, Madrid, Spain and their bioclimatic adaptation

Underground dwellings are the maximum example of the vernacular architecture adaptation to the climatic conditions in areas with high annual and daily thermal fluctuations. This paper summarizes the systematic research about the energy performance of this popular architecture and their adaptation to the outdoor conditions in the case of the low area of the River Tajuña and its surroundings. Some considerations on their maintenance and renovation arise from the research.

Geomorphological analysis and evolution of an altered floodplain drainage system. The case of the Partido Stream (Spain)

The Partido Stream is a small torrential course that flows into the marsh of the Doñana National Park, an area that was declared a World Heritage Site in 1994. Before 1981, floods occurred, and the stream overflowed onto a floodplain. As an old alluvial fan, the floodplain has its singular orography and functionality. Fromthe floodplain, several drainage channels, locally called caño, discharged into themarsh. The Partido Streamhad themorphology of a caño and covered approximately 8 km from the old fan to the marsh. The stream was straightened and channelised in 1981 to cultivate the old fan. This resulted in floods that were concentrated between the banks in the following years, which caused the depth of water and the shear stress to increase, thus, scouring the river bed and river banks. In this case, the eroded materials were carried towards the marsh where a new alluvial fan evolved. Control measures on the old fan were implemented in 2006 to stop the development of the new alluvial fan downstream over the marsh. Thus, the stream would partially recover its original behaviour that it had before channelisation, moving forwards in a new, balanced state. The present study describes the geomorphological evolution that channelisation has caused since 1981 and the later slow process of recovery of the original hydraulic-sedimentation regime since 2006. Additionally, it deepens the understanding of the original hydraulic behaviour of the stream, combining field data and 2D simulations.

Responses of riparian guilds to flowalterations in a Mediterranean stream

Questions: Do Mediterranean riparian guilds show distinct responses to stream water declines? If observed,which are the most sensitive and resilient guilds and theirmost affected attributes? Location: Tie¿tar river below the Rosarito dam, central-western Spain. Methods: We identified riparian guilds based on key woody species features and species distribution within this Mediterranean river corridor, and evaluated similarity of their responses to long-term flow alteration (i.e. stream water declines since dam construction in 1959). Hierarchical cluster analysis was used to group surveyed vegetation bands according to species composition. The groups were designated as riparian guilds where each vegetation group comprising a guild: (1) contains species sharing similar features (using PCA); and (2) shares a similar environment (using DCA). Changes in several guild attributes (i.e. dominance and species composition, diversity and establishment patterns) during the regulated period were compared statistically. We used pre- and post-dam established vegetation bands identified based on old (1956) and modern (2006) aerial photographs and field measurements of woody species diameter. Results: Responses to flow alterations varied between guilds according to ecological requirements of their species. The ability to survive water stress (i.e. ?Xeric? guilds) and drag forces caused by floods (?Torrential? guilds) allowed certain pioneer shrub-dominated guilds (e.g. Flueggea tinctoria and Salix salviifolia) to spread on newly emerged surfaces downward to the main channel after flow alterations, although new shrubland had less species diversity than pre-dam shrubland. In contrast, new hydromorphological conditions following damming limited recruitment of native late-successional tree guilds sensitive to floods (to drag forces, inundation and anoxia; i.e. ?Slow-water? and ?Flood-sensitive?, respectively) and those with greater water requirements (i.e. ?Hydric?) (e.g. Alnus glutinosa and Celtis australis), although species diversity increased in this mature forest through co-existence of remaining riparian species and new arrival of upland species. Conclusions: Changes in several riparian attributes after flow alterations differed between guilds. Stream water declines after damming caused shifts in species-poor pioneer shrubland downwards to the watered channel, resulting in severe declines ofmaturenative forest.Understanding vegetation guild responses provides information about general trends in plant populations and assemblage structures expected to occur during river development and flow regulation, increasing our capacity to detect and synthesize complex flowalteration?riparian ecosystem response relationships, and anticipate irreversible impacts.

Optimización de la succión de sólidos sumergidos utilizando bombas centrífugas con velocidad variable

La acumulación de material sólido en embalses, cauces fluviales y en zonas marítimas hace que la extracción mecánica de estos materiales por medio de succión sea cada vez mas frecuente, por ello resulta importante estudiar el rendimiento de la succión de estos materiales analizando la forma de las boquillas y los parámetros del flujo incluyendo la bomba. Esta tesis estudia, mediante equipos experimentales, la eficacia de distintos dispositivos de extracción de sólidos (utilizando boquillas de diversas formas y bombas de velocidad variable). El dispositivo experimental ha sido desarrollado en el Laboratorio de Hidráulica de la E.T.S.I. de Caminos, C. y P. de la Universidad Politécnica de Madrid. Dicho dispositivo experimental incluye un lecho sumergido de distintos tipos de sedimentos, boquillas de extracción de sólidos y bomba de velocidad variable, así como un elemento de separación del agua y los sólidos extraídos. Los parámetros básicos analizados son el caudal líquido total bombeado, el caudal sólido extraído, diámetro de la tubería de succión, forma y sección de la boquilla extractora, así como los parámetros de velocidad y rendimiento en la bomba de velocidad variable. Los resultados de las medidas obtenidas en el dispositivo experimental han sido estudiados por medio del análisis dimensional y con métodos estadísticos. A partir de este estudio se ha desarrollado una nueva formulación, que relaciona el caudal sólido extraído con los diámetros de tubería y boquilla, caudal líquido bombeado y velocidad de giro de la bomba. Así mismo, desde el punto de vista práctico, se han analizado la influencia de la forma de la boquilla con la capacidad de extracción de sólidos a igualdad del resto de los parámetros, de forma que se puedan recomendar que forma de la boquilla es la más apropiada. The accumulation of solid material in reservoirs, river channels and sea areas causes the mechanical extraction of these materials by suction is becoming much more common, so it is important to study the performance of the suction of these materials analyzing the shape of the nozzles and flow parameters, including the pump. This thesis studies, using experimental equipment, the effectiveness of different solids removal devices (using nozzles of different shapes and variable speed pumps). The experimental device was developed at the Hydraulics Laboratory of the Civil University of the Polytechnic University of Madrid. The device included a submerged bed with different types of sediment solids, different removal nozzles and variable speed pump. It also includes a water separation element and the solids extracted. The key parameters analyzed are the total liquid volume pumped, the solid volume extracted, diameter of the suction pipe, a section of the nozzle and hood, and the parameters of speed and efficiency of the variable speed pump. The basic parameters analyzed are the total liquid volume pumped, the removed solid volume, the diameter of the suction pipe, the shape and cross-section of the nozzle, and the parameters of speed, efficiency and energy consumed by the variable speed pump. The measurements obtained on the experimental device have been studied with dimensional analysis and statistical methods. The outcome of this study is a new formulation, which relates the solid volume extracted with the pipe and nozzle diameters, the pumped liquid flow and the speed of the pump. Also, from a practical point of view, the influence of the shape of the nozzle was compared with the solid extraction capacity, keeping equal the rest of the parameters. So, a recommendation of the best shape of the nozzle can be given.

Risk-based methodology for parameter calibration of a reservoir flood control model

Flash floods are of major relevance in natural disaster management in the Mediterranean region. In many cases, the damaging effects of flash floods can be mitigated by adequate management of flood control reservoirs. This requires the development of suitable models for optimal operation of reservoirs. A probabilistic methodology for calibrating the parameters of a reservoir flood control model (RFCM) that takes into account the stochastic variability of flood events is presented. This study addresses the crucial problem of operating reservoirs during flood events, considering downstream river damages and dam failure risk as conflicting operation criteria. These two criteria are aggregated into a single objective of total expected damages from both the maximum released flows and stored volumes (overall risk index). For each selected parameter set the RFCM is run under a wide range of hydrologic loads (determined through Monte Carlo simulation). The optimal parameter set is obtained through the overall risk index (balanced solution) and then compared with other solutions of the Pareto front. The proposed methodology is implemented at three different reservoirs in the southeast of Spain. The results obtained show that the balanced solution offers a good compromise between the two main objectives of reservoir flood control management

Classification of natural flow regimes in the Ebro basin (Spain) by using a wide range of hydrologic parameters

Clasificación de tipos de régimenes naturales de caudales a partir de parámetros de tres componentes del régimen fluvial: magnitud, frecuencia y duración.

The MIS 5 palaeoenvironmental record in the SE Mediterranean coast of the Iberian Peninsula (Río Antas, Almería, Spain)

Se realiza un estudio detallado del episodio cálido MIS 5 en la zona sureste de la Península Ibérica. Se realiza la reconstrucción paleoambiental a partir del estudio polínico y biomarcadores de un sondeo perforado en la costa de Almería. La cronología se estableció a partir del método de racemizaciónd e aminoácidos.Landwards of a MIS5 bar, a borehole core (SRA) was analyzed to establish the relationship between the lagoonal record and the raised beach deposits in the surroundings of the Antas river mouth and to reconstruct the Pleistocene palaeoenvironmental evolution 5 of the southern Mediterranean coast of the Iberian Peninsula. 63 samples were recovered for amino acid racemization dating, 86 samples for sedimentological and paleontological determination, 37 samples for pollen identification and 54 for biomarker analysis. AAR revealed that the borehole record contains MIS11, MIS6 and MIS5 deposits, the latter extensively represented. During the end of MIS6 and MIS5, a sand 10 barrier developed and created a shallow lagoon with alternating terrestrial inputs this process being common in other Mediterranean realms. Litho- and biofacies allowed the identification of distinct paleoenvironments through time, with the presence of a lagoonal environment alternating with alluvial fan progradation. Biomarkers indicated constant input from terrestrial plants, together with variable development of aquatic 15 macrophytes. The palynological content allowed the reconstruction of the paleoclimatological conditions during MIS6 and 5, with evidence of seven scenarios characterized by alternating arid and relatively humid conditions

Estudio del estado de la vegetación de ribera en la España peninsular. Implicaciones de la alteración hidrológica y herramientas para su manejo y gestión

El objetivo general de este trabajo es explorar las potenciales interacciones entre la alteración hidrológica y el estado de la vegetación de ribera en diversas cuencas hidrográficas españolas. La mayor parte del área de estudio está dentro de la región Mediterránea, una región caracterizada por un particular comportamiento climatológico, ecológico y socio-económico. Las cuencas estudiadas son: Guadiana, Guadalquivir, Tajo, y Duero. Para complementar el estudio y comparar resultados con otras regiones climáticas españolas se estudiaron dos Demarcaciones atlánticas: Cantábrico y Miño-Sil. El funcionamiento fluvial, en las áreas mediterráneas, presenta grandes variaciones en el régimen hídrico, siendo uno de los principales controladores de la estructura, composición y distribución de la vegetación de ribera. Para investigar las interacciones mencionadas previamente, se presenta un nuevo índice, Riparian Forest Evaluation (RFV). El objetivo de este índice es valorar el estado de la vegetación de ribera en base a los principales controladores hidro-morfológicos responsables de la dinámica fluvial, y por tanto, relacionados con el desarrollo del corredor ribereño. RFV divide la evaluación del bosque de ribera en cuatro componentes: continuidad longitudinal, transversal, y vertical (dimensiones espaciales), y condiciones del regenerado (dimensión temporal). La clasificación final está basada en las mismas cinco clases fijadas por la Directiva europea Marco del Agua (DMA) (2000/60/CE) para valorar el estado ecológico de las masas de agua. La aplicación de este índice en 187 masas de agua ha mostrado su facilidad de aplicación y su consistencia desde un punto de vista legislativo y técnicocientífico. En paralelo al diseño del índice RFV, se ha desarrollado una nueva herramienta para dar apoyo a la evaluación del bosque de ribera (RFV) y la extracción de variables hidromorfológicas a escala de masa de agua en lugar de a escala local (muestreo de campo local). Se trata de Riparian Characterisation by LiDAR (RiC-DAR), que permite valorar el estado del bosque de ribera de una manera semiautomática, en un modo cuasi-continuo, usando LiDAR de alta resolución. Esto hecho permite mejorar significativamente la calidad y cantidad de información comparado con la toma de datos en campo, lo que permite reducir los recursos, particularmente cuando se trabaja a escala de masas de agua. Una de las potenciales causas de la degradación del bosque de ribera es la alteración hidrológica; así una vez se ha realizado la evaluación del bosque de ribera basada en elementos hidro-morfológicos ligados al régimen hídrico (RFV), se han identificado las potenciales relaciones entre la alteración hidrológica y la degradación de la vegetación riparia. Para ello, se requiere contar con series de aforos fiables y de una duración apropiada. Para satisfacer este requerimiento, se ha creado una nueva herramienta: el Servidor de Datos para el Estudio de la Alteración Hidrológica (SEDAH). Esta herramienta genera datos diarios y mensuales completados para más años, construyendo así bases de datos más aptas para el estudio de la alteración hidrológica. (http://ambiental.cedex.es/Sedah) Haciendo uso de las herramientas y métodos desarrollados previamente, se han calculado diferentes indicadores de alteración hidrológica en 87 masas de agua que han sido analizados conjuntamente con el estado de la vegetación de ribera. Los resultados estadísticos han mostrado relaciones significativas entre ellos: la degradación de la vegetación podría estar fuertemente ligada a la alteración del régimen hídrico en años secos y a las sequías en el entorno mediterráneo. A su vez se ha analizado la relación del estado del bosque de ribera con el estado ecológico basado en la DMA, mostrando una relación no significativa. Esta y otras potenciales relaciones son discutidas a lo largo del documento. Los resultados permiten proponer recomendaciones de gestión de la vegetación de ribera y de manejo del régimen de caudales para masas de agua reguladas. ABSTRACT The general objective of this work is to explore the potential interactions between hydrologic alteration and degradation of the riparian vegetation, mainly focused in the Mediterranean Environment. The majority of the study area is part of the Spanish Mediterranean region, a geographical environment characterized by a singular climatologic, ecological and socio-economical behavior. The basins analysed in this work are: Guadiana, Guadalquivir, Tagus, Douro. In order to complete the results and compare those to other climatic regions in Spain, two Atlantic Districts where selected: Cantábrico and Miño-Sil. The river functioning, in the Mediterranean areas, presents great variations in the flow regimes being one of the main drivers of the riparian vegetation development. To explore the interactions stated above, a new index is presented, Riparian Forest Evaluation (RFV). This index is aimed to assess the status of the riparian vegetation based on the main hydromorphological drivers responsible of the river dynamic, and so, related to the development of the riparian corridor. RFV split the evaluation of the riparian forest into four components: longitudinal continuity, transversal continuity, vertical (structure) continuity and regeneration (temporal) continuity. The final classification is based in the same five classes to those stated in the European Water Frame Work directive to assess the ecological status. The application of this index over 187 water bodies has shown to be easily applicable and consistent from a regulatory perspective. In parallel to the design of RFV, a new tool has been developed to enhance the evaluation of the riparian forest and river morphology (RFV and morphological parameters) at water body scale rather than at local scale, i.e. when field surveyed at different sites. The Riparian Characterisation by LiDAR, RiC-DAR allows to assess the status of the riparian vegetation semi-automatically in a quasi-continuous way using high resolution LiDAR. This improves significantly the quantity and quality of information gathered through field sampling methods, reducing resources when working at larger scales. One of the potential major causes of degradation of the riparian forest is the hydrologic alteration; hence, once the evaluation of the riparian forest is done consistently based on hydro-morphological features linked to the hydrological regime (RVF), this work has identified potential relationships between hydrologic alteration and degradation of riparian vegetation. In order to do this, it is required to count with reliable series of flow records describing both reference and altered regimes. To satisfy this need, a new tool has been created, SEDAH, data server for assessing hydrologic alteration. This tool has completed daily and monthly gaps in the flow series to build up an improved database to assess the hydrologic alteration. This application is available on line (http://ambiental.cedex.es). Making use of the tools and methods developed previously, this work uses these data to work out indicators of hydrologic alteration through 87 water bodies to be analysed against the riparian status. These indicators are statistically analysed exploring significant relationships with the status of riparian vegetation and ecological status, showing some potential significant relationships; hence it seems that the degradation of riparian vegetation, particularly the regeneration, is associated with the alteration of the hydrologic regimen in dry years and draughts in Mediterranean environments. Furthermore, the analysis of the status of the ecological status and the status of the riparian vegetation has shown the lack of significant influence of the riparian vegetation in the final ecological status using the WFD approach applied in Spain. This and other potential relationships are discussed in this work. The results allow giving guidance on the management of both riparian vegetation and environmental flows of water bodies affected by flow regulation.

La reutilización de efluentes depurados en España: retrospectiva, desarrollo del marco normativo, estudio de las tecnologías de regeneración frente a los biorreactores de membrana y sus costes en función del uso

La reutilización de efluentes depurados siempre ha sido una opción en lugares con déficit coyuntural o estructural de recursos hídricos, se haya o no procedido a la regulación y planificación de esta práctica. La necesidad se crea a partir de las demandas de una zona, normalmente riego agrícola, que ven un mejor desarrollo de su actividad por contar con este recurso. España es el país de la UE que más caudal reutiliza, y está dentro de los diez primeros a nivel mundial. La regulación de esta práctica por el RD 1620/2007, ayudó a incorporar la reutilización de efluentes depurados a la planificación hidrológica como parte de los programas de medidas, con objeto de mitigar presiones, como son las extracciones de agua superficial y subterránea, o mejoras medioambientales evitando un vertido. El objeto de este trabajo es conocer la situación de la reutilización de efluentes depurados en España, los diferentes escenarios y planteamientos de esta actividad, el desarrollo del marco normativo y su aplicabilidad, junto a los tratamientos que permiten alcanzar los límites de calidad establecidos en la normativa vigente, en función de los distintos usos. Además, se aporta un análisis de costes de las distintas unidades de tratamiento y tipologías de líneas de regeneración, tanto de las utilizadas después de un tratamiento secundario como de otras opciones de depuración, como son los biorreactores de membrana (MBRs). Para el desarrollo de estos objetivos, en primer lugar, se aborda el conocimiento de la situación de la reutilización en España a través de una base de datos diseñada para cubrir todos los aspectos de esta actividad: datos de la estación depuradora de aguas residuales (EDAR), de la estación regeneradora (ERA), caudales depurados, reutilizados, volúmenes utilizados y ubicación de los distintos usos, tipos de líneas de tratamiento, calidades del agua reutilizada, etc. Las principales fuentes de información son las Confederaciones Hidrográficas (CCHH) a través de las concesiones de uso del agua depurada, las entidades de saneamiento y depuración de las distintas comunidades autónomas (CCAA), ayuntamientos, Planes Hidrológicos de Cuenca (PHC) y visitas a las zonas más emblemáticas. Además, se revisan planes y programas con el fin de realizar una retrospectiva de cómo se ha ido consolidando y desarrollando esta práctica en las distintas zonas de la geografía española. Se han inventariado 322 sistemas de reutilización y 216 tratamientos de regeneración siendo el más extendido la filtración mediante filtro arena seguido de una desinfección mediante hipoclorito, aunque este tratamiento se ha ido sustituyendo por un físico-químico con decantación lamelar, filtro de arena y radiación ultravioleta, tratamiento de regeneración convencional (TRC), y otros tratamientos que pueden incluir membranas, tratamientos de regeneración avanzados (TRA), con dosificación de hipoclorito como desinfección residual, para adaptarse al actual marco normativo. El uso más extendido es el agrícola con el 70% del caudal total reutilizado, estimado en 408 hm3, aunque la capacidad de los tratamientos de regeneración esperada para 2015, tras el Plan Nacional de Reutilización de Aguas (PNRA), es tres veces superior. Respecto al desarrollo normativo, en las zonas donde la reutilización ha sido pionera, las administraciones competentes han ido desarrollando diferentes recomendaciones de calidad y manejo de este tipo de agua. El uso agrícola, y en zonas turísticas, el riego de campos de golf, fueron los dos primeros usos que tuvieron algún tipo de recomendación incluso reglamentación. Esta situación inicial, sin una normativa a nivel estatal ni recomendaciones europeas, creó cierta incertidumbre en el avance de la reutilización tanto a nivel de concesiones como de planificación. En la actualidad sigue sin existir una normativa internacional para la reutilización y regeneración de efluentes depurados. Las recomendaciones de referencia a nivel mundial, y en concreto para el uso agrícola, son las de la OMS (Organización Mundial de la Salud) publicadas 1989, con sus posteriores revisiones y ampliaciones (OMS, 2006). Esta norma combina tratamientos básicos de depuración y unas buenas prácticas basadas en diferentes niveles de protección para evitar problemas sanitarios. Otra normativa que ha sido referencia en el desarrollo del marco normativo en países donde se realiza esta práctica, son las recomendaciones dadas por la Agencia Medioambiente Estadunidense (USEPA, 2012) o las publicadas por el Estado de California (Título 22, 2001). Estas normas establecen unos indicadores y valores máximos dónde el tratamiento de regeneración es el responsable de la calidad final en función del uso. Durante 2015, la ISO trabajaba en un documento para el uso urbano donde se muestra tanto los posibles parámetros que habría que controlar como la manera de actuar para evitar posibles riesgos. Por otro lado, la Comisión Europea (CE) viene impulsando desde el 2014 la reutilización de aguas depuradas dentro del marco de la Estrategia Común de Implantación de la Directiva Marco del Agua, y fundamentalmente a través del grupo de trabajo de “Programas de medidas”. Para el desarrollo de esta iniciativa se está planteando sacar para 2016 una guía de recomendaciones que podría venir a completar el marco normativo de los distintos Estados Miembros (EM). El Real Decreto 1620/2007, donde se establece el marco jurídico de la reutilización de efluentes depurados, tiende más a la filosofía implantada por la USEPA, aunque la UE parece más partidaria de una gestión del riesgo, donde se establecen unos niveles de tolerancia y unos puntos de control en función de las condiciones socioeconómicas de los distintos Estados, sin entrar a concretar indicadores, valores máximos o tratamientos. Sin embargo, en la normativa estadounidense se indican una serie de tratamientos de regeneración, mientras que, en la española, se hacen recomendaciones a este respecto en una Guía sin validez legal. Por tanto, queda sin regular los procesos para alcanzar estos estándares de calidad, pudiendo ser éstos no apropiados para esta práctica. Es el caso de la desinfección donde el uso de hipoclorito puede generar subproductos indeseables. En la Guía de recomendaciones para la aplicación del RD, publicada por el Ministerio de Agricultura y Medioambiente (MAGRAMA) en 2010, se aclaran cuestiones frecuentes sobre la aplicación del RD, prescripciones técnicas básicas para los sistemas de reutilización, y buenas prácticas en función del uso. Aun así, el RD sigue teniendo deficiencias en su aplicación siendo necesaria una revisión de la misma, como en las frecuencias de muestreo incluso la omisión de algunos parámetros como huevos de nematodos que se ha demostrado ser inexistentes tras un tratamiento de regeneración convencional. En este sentido, existe una tendencia a nivel mundial a reutilizar las aguas con fines de abastecimiento, incluir indicadores de presencia de virus o protozoos, o incluir ciertas tecnologías como las membranas u oxidaciones avanzadas para afrontar temas como los contaminantes emergentes. Otro de los objetivos de este trabajo es el estudio de tipologías de tratamiento en función de los usos establecidos en el RD 1620/2007 y sus costes asociados, siendo base de lo establecido a este respecto en la Guía y PNRA anteriormente indicados. Las tipologías de tratamiento propuestas se dividen en líneas con capacidad de desalar y las que no cuentan con una unidad de desalación de aguas salobres de ósmosis inversa o electrodiálisis reversible. Se realiza esta división al tener actuaciones en zonas costeras donde el agua de mar entra en los colectores, adquiriendo el agua residual un contenido en sales que es limitante en algunos usos. Para desarrollar este objetivo se han estudiado las unidades de tratamiento más implantadas en ERAs españolas en cuanto a fiabilidad para conseguir determinada calidad y coste, tanto de implantación como de explotación. El TRC, tiene un coste de implantación de 28 a 48 €.m-3.d y de explotación de 0,06 a 0,09 €. m-3, mientras que, si se precisara desalar, este coste se multiplica por diez en la implantación y por cinco en la explotación. En caso de los usos que requieren de TRA, como los domiciliarios o algunos industriales, los costes serían de 185 a 398 €.m-3.d en implantación y de 0,14 a 0,20 €.m-3 en explotación. En la selección de tecnologías de regeneración, la capacidad del tratamiento en relación al coste es un indicador fundamental. Este trabajo aporta curvas de tendencia coste-capacidad que sirven de herramienta de selección frente a otros tratamientos de regeneración de reciente implantación como son los MBR, u otros como la desalación de agua de mar o los trasvases entre cuencas dentro de la planificación hidrológica. En España, el aumento de las necesidades de agua de alta calidad en zonas con recursos escasos, aumento de zonas sensibles como puntos de captación para potables, zonas de baño o zonas de producción piscícola, y en ocasiones, el escaso terreno disponible para la implantación de nuevas plantas depuradoras (EDARs), han convertido a los MBRs, en una opción dentro del marco de la reutilización de aguas depuradas. En este trabajo, se estudia esta tecnología frente a los TRC y TRA, aportando igualmente curvas de tendencia coste-capacidad, e identificando cuando esta opción tecnológica puede ser más competitiva frente a los otros tratamientos de regeneración. Un MBR es un tratamiento de depuración de fangos activos donde el decantador secundario es sustituido por un sistema de membranas de UF o MF. La calidad del efluente, por tanto, es la misma que el de una EDAR seguida de un TRA. Los MBRs aseguran una calidad del efluente para todos los usos establecidos en el RD, incluso dan un efluente que permite ser directamente tratado por las unidades de desalación de OI o EDR. La implantación de esta tecnología en España ha tenido un crecimiento exponencial, pasando de 13 instalaciones de menos de 5.000 m3. d-1 en el 2006, a más de 55 instalaciones en operación o construcción a finales del 2014, seis de ellas con capacidades por encima de los 15.000 m3. d-1. Los sistemas de filtración en los MBR son los que marcan la operación y diseño de este tipo de instalaciones. El sistema más implantado en España es de membrana de fibra hueca (MFH), sobre todo para instalaciones de gran capacidad, destacando Zenon que cuenta con el 57% de la capacidad total instalada. La segunda casa comercial con mayor número de plantas es Kubota, con membranas de configuración placa plana (MPP), que cuenta con el 30 % de la capacidad total instalada. Existen otras casas comerciales implantadas en MBR españoles como son Toray, Huber, Koch o Microdym. En este documento se realiza la descripción de los sistemas de filtración de todas estas casas comerciales, aportando información de sus características, parámetros de diseño y operación más relevantes. El estudio de 14 MBRs ha posibilitado realizar otro de los objetivos de este trabajo, la estimación de los costes de explotación e implantación de este tipo de sistemas frente a otras alternativas de tratamiento de regeneración. En este estudio han participado activamente ACA y ESAMUR, entidades públicas de saneamiento y depuración de Cataluña y Murcia respectivamente, que cuentan con una amplia experiencia en la explotación de este tipo de sistemas. Este documento expone los problemas de operación encontrados y sus posibles soluciones, tanto en la explotación como en los futuros diseños de este tipo de plantas. El trabajo concluye que los MBRs son una opción más para la reutilización de efluentes depurados, siendo ventajosos en costes, tanto de implantación como de explotación, respecto a EDARs seguidas de TRA en capacidades por encima de los 10.000 m3.d-1. ABSTRACT The reuse of treated effluent has always been an option in places where a situational or structural water deficit exists, whether regulatory and/or planning efforts are completed or not. The need arises from the demand of a sector, commonly agricultural irrigation, which benefits of this new resource. Within the EU, Spain is ahead in the annual volume of reclaimed water, and is among the top ten countries at a global scale. The regulation of this practice through the Royal Decree 1620/2007 has helped to incorporate the water reuse to the hydrological plans as a part of the programme of measures to mitigate pressures such as surface or ground water extraction, or environmental improvements preventing discharges. The object of this study is to gain an overview of the state of the water reuse in Spain, the different scenarios and approaches to this activity, the development of the legal framework and its enforceability, together with the treatments that achieve the quality levels according to the current law, broken down by applications. Additionally, a cost analysis of technologies and regeneration treatment lines for water reclamation is performed, whereas the regeneration treatment is located after a wastewater treatment or other options such as membrane bioreactors (MBR). To develop the abovementioned objectives, the state of water reuse in Spain is studied by means of a database designed to encompass all aspects of the activity: data from the wastewater treatment plants (WWTP), from the water reclamation plants (WRP), the use of reclaimed water, treated water and reclaimed water annual volumes and qualities, facilities and applications, geographic references, technologies, regeneration treatment lines, etc. The main data providers are the River Basin authorities, through the concession or authorization for water reuse, (sanitary and wastewater treatment managers from the territorial governments, local governments, Hydrological Plans of the River Basins and field visits to the main water reuse systems. Additionally, a review of different plans and programmes on wastewater treatment or water reuse is done, aiming to put the development and consolidation process of this activity in the different regions of Spain in perspective. An inventory of 322 reuse systems and 216 regeneration treatments has been gathered on the database, where the most extended regeneration treatment line was sand filtration followed by hypochlorite disinfection, even though recently it is being replaced by physical–chemical treatment with a lamella settling system, depth sand filtration, and a disinfection with ultraviolet radiation and hypochlorite as residual disinfectant, named conventional regeneration treatment (CRT), and another treatment that may include a membrane process, named advanced regeneration treatment (ART), to adapt to legal requirements. Agricultural use is the most extended, accumulating 70% of the reclaimed demand, estimated at 408 hm3, even though the expected total capacity of WRPs for 2015, after the implementation of the National Water Reuse Plan (NWRP) is three times higher. According to the development of the water reuse legal framework, there were pioneer areas where competent authorities developed different quality and use recommendations for this new resource. Agricultural use and golf course irrigation in touristic areas were the first two uses with recommendations and even legislation. The initial lack of common legislation for water reuse at a national or European level created some doubts which affected the implementation of water reuse, both from a planning and a licensing point of view. Currently there is still a lack of common international legislation regarding water reuse, technologies and applications. Regarding agricultural use, the model recommendations at a global scale are those set by the World Health Organization published in 1989, and subsequent reviews and extensions about risk prevention (WHO, 2006). These documents combine wastewater treatments with basic regeneration treatments reinforced by good practices based on different levels of protection to avoid deleterious health effects. Another relevant legal reference for this practices has been the Environmental Protection Agency of the US (USEPA, 2012), or those published by the State of California (Title 22, 2001). These establish indicator targets and maximum thresholds where regeneration treatment lines are responsible for the final quality according to the different uses. During 2015, the ISO has worked on a document aimed at urban use, where the possible parameters to be monitored together with risk prevention have been studied. On the other hand, the European Commission has been promoting the reuse of treated effluents within the Common Implementation Strategy of the Water Framework Directive, mainly through the work of the Programme of Measures Working Group. Within this context, the publication of a recommendation guide during 2016 is intended, as a useful tool to fill in the legal gaps of different Member States on the matter. The Royal Decree 1620/2007, where the water reuse regulation is set, resembles the principles of the USEPA more closely, even though the EU shows a tendency to prioritize risk assessment by establishing tolerance levels and thresholds according to socioeconomic conditions of the different countries, without going into details of indicators, maximum thresholds or treatments. In contrast, in the US law, regeneration treatments are indicated, while in the Spanish legislation, the only recommendations to this respect are compiled in a non-compulsory guide. Therefore, there is no regulation on the different treatment lines used to achieve the required quality standards, giving room for inappropriate practices in this respect. This is the case of disinfection, where the use of hypochlorite may produce harmful byproducts. In the recommendation Guide for the application of the Royal Decree (RD), published by the Ministry of Agriculture and Environment (MAGRAMA) in 2010, clarifications of typical issues that may arise from the application of the RD are given, as well as basic technical parameters to consider in reuse setups, or good practices according to final use. Even so, the RD still presents difficulties in its application and requires a review on issues such as the sampling frequency of current quality parameters or even the omission of nematode eggs indicator, which have been shown to be absent after CRT. In this regard, there is a global tendency to employ water reuse for drinking water, including indicators for the presence of viruses and protozoans, or to include certain technologies such as membranes or advanced oxidation processes to tackle problems like emerging pollutants. Another of the objectives of this study is to provide different regeneration treatment lines to meet the quality requirements established in the RD 1620/2007 broken down by applications, and to estimate establishment and operational costs. This proposal has been based on what is established in the above mentioned Guide and NWRP. The proposed treatment typologies are divided in treatment trains with desalination, like reverse osmosis or reversible electrodialisis, and those that lack this treatment for brackish water. This separation is done due to coastal facilities, where sea water may permeate the collecting pipes, rising salt contents in the wastewater, hence limiting certain uses. To develop this objective a study of the most common treatment units set up in Spanish WRPs is conducted in terms of treatment train reliability to obtain an acceptable relationship between the required quality and the capital and operational costs. The CRT has an establishment cost of 28 to 48 €.m-3.d and an operation cost of 0.06 to 0.09 €.m-3, while, if desalination was required, these costs would increase tenfold for implementation and fivefold for operation. In the cases of uses that require ART, such as residential or certain industrial uses, the costs would be of 185 to 398 €.m-3.d for implementation and of 0.14 to 0.20 €.m-3 for operation. When selecting regeneration treatment lines, the relation between treatment capacity and cost is a paramount indicator. This project provides cost-capacity models for regeneration treatment trains. These may serve as a tool when selecting between different options to fulfill water demands with MBR facilities, or others such as sea water desalination plants or inter-basin water transfer into a water planning framework. In Spain, the requirement for high quality water in areas with low resource availability, the increasing number of sensitive zones, such as drinking water extraction, recreational bathing areas, fish protected areas and the lack of available land to set up new WWTPs, have turned MBRs into a suitable option for water reuse. In this work this technology is analyzed in contrast to CRT and ART, providing cost-capacity models, and identifying when and where this treatment option may outcompete other regeneration treatments. An MBR is an activated sludge treatment where the secondary settling is substituted by a membrane system of UF or MF. The quality of the effluent is, therefore, comparable to that of a WWTP followed by an ART. MBRs ensure a sufficient quality level for the requirements of the different uses established in the RD, even producing an effluent that can be directly treated in OI or EDR processes. The implementation of this technology in Spain has grown exponentially, growing from 13 facilities with less than 5000 m3.d-1 in 2006 to above 55 facilities operating by the end of 2014, 6 of them with capacities over 15000 m3.d-1. The membrane filtration systems for MBR are the ones that set the pace of operation and design of this type of facilities. The most widespread system in Spain is the hollow fiber membrane configuration, especially on high flow capacities, being Zenon commercial technology, which mounts up to 57% of the total installed capacity, the main contributor. The next commercial technology according to plant number is Kubota, which uses flat sheet membrane configuration, which mounts up to 30% of the total installed capacity. Other commercial technologies exist within the Spanish MBR context, such as Toray, Huber, Koch or Microdym. In this document an analysis of all of these membrane filtration systems is done, providing information about their characteristics and relevant design and operation parameters. The study of 14 full scale running MBRs has enabled to pursue another of the objectives of this work: the estimation of the implementation and operation costs of this type of systems in contrast to other regeneration alternatives. Active participation of ACA and ESAMUR, public wastewater treatment and reuse entities of Cataluña and Murcia respectively, has helped attaining this objective. A number of typical operative problems and their possible solutions are discussed, both for operation and plant design purposes. The conclusion of this study is that MBRs are another option to consider for water reuse, being advantageous in terms of both implementation and operational costs, when compared with WWTPs followed by ART, when considering flow capacities above 10000 m3.d-1.