General National Id Spain_03 Site name Segovia province, left bank of Voltoya and Eresma Rivers. Summary Managed Aquifer Recharge in Los Arenales (Segovia, Spain). As showed by data obtained after 8 effective recharge cycles carried out in an experimental area (Cubeta de San Tiuste) at Los Arenales Aquifer (Segovia, Duero River Basin, Spain), Managed Aquifer Recharge can be more than an effective measure for storing large quantities of water in underground aquifers to naturally increase the quantity of groundwater in times of shortage: it can also result in an enhanced natural condition of aquifers and water availability. Also, the natural cleaning process of water percolating through the soils when entering the AGR showed its potential for providing improved water quality Light or indepth? Light NUTS Code Castilla y León RBD code ES020 Transboundary 0 Data provider Estefanía Ibáñez (IMDEA Water) in close cooperation with Enrique Fernández Escalante (TRAGSA-SEPI) whose valuable contribution is acknowledged and very much appreciated. Source(s) La recarga artificial de acuíferos. Marco legal que regula sus aplicaciones. 2002-2012, una década de recarga gestionada. Acuífero de la Cubeta de Santiuste (Castilla y Leon) DINA-MAR. La gestión de la recarga artificial de acuíferos en el marco del desarrollo sostenible. Desarrollo tecnológico. Rechargable sustainability: the key is the storage Recarga artificial de acuíferos en cuencas fluviales. Aspectos cualitativos y medioambientales. Criterios técnicos derivados de la experiencia en la Cubeta de Santiuste (Segovia) Proposicion de un sistema de caracterizacion de humedales degradados susceptibles de regeneracion hídrica mediante operaciones de recarga artificial de acuíferos Cinco anos de recarga artificial en el acuífero de la Cubeta de Santiuste (Segovia) Contribution to the hydrogeological knowledge of an artificial recharge area based in hydrochemical investigation. Los Arenales site, Duero basin, Spain. Hydrogeological studies previous to the artificial recharge of Los Arenales aquifer, Duero basin (Spain) NWRM(s) implemented in the case study Restoration of natural infiltration to groundwater Longitude -4.572 Latitude 41.1445 Site information Climate zone cool temperate moist Mean rainfall 460,709991455078 Mean rainfall unit mm/year Average temperature 11,1599998474121 Mean evaportranspiration 378,779998779297 Mean evaportranspiration unit mm/year Type Actual Test Site Water quality inflow unit mg/L Average slope range 0-1% Monitoring maintenance Monitoring impacts effects 1 Monitoring location Catchment outlet Monitoring upstream station Dina-Mar ZNS-1 (Sig-Pac plot 40:221:0:0:1:6244; Coord 369694:4557512) Monitoring downstream station Dina-Mar ZNS-2 (Sig-Pac plot 40:65:265:0:7:5372:2; Coord 369246:4561559) Performance Performance impact estimation method Laboratory Performance impact estimation information Changes in water table have been studied with the Water Table Fluctiation Method (Healy and Cook, 2002). Studies of the non-saturated zone were carried out with control stations, which measured humidity, temperature and pressure (or tension). The latest monitoring technique is the use of a thermal camera to study the evolution of silting Design & implementations Application scale Plot Installation date 2002 Age 12 Performance timescale < 1 year Area (ha) 4800 Area subject to Land use change or Management/Practice change (ha) 7,55819988250732 Size 27960 Size unit m2 Design capacity description The system was designed for a maximum water flow of 1000 l/s (or 1 m3/s) and a maximum annual volume of 8 hm3. Basis of design Peak flow (for a standard return period of 5 years) = 100 m3/s Peak flow (for a return period of 500 years) = 560 m3/s Constraints In winter, water freezing reduce infiltration to the aquifer. This might be relevant considering that the concesion of water for this propose goes from November to April. Some years have not been successful due to silting up in soakways and pond. The water transfer from Voltoya River to the recharge channel needed to be stopped during heavy rain days in order to avoid flooding. Additionally, the Lisse effect (excess of air trapped in to the aquifer reduces the infiltration capacity) has been a problem during the implementation, having to modify the design and structure of the devices. Erotion of soakways/channels banksides, jeopardising stability. The transfer of water to the recharge system was only allowed is the flow in Voltoya river was be above 600 l/s (in order to guarantee the ecological flow. Favourable preconditions The channel was designed to take advantage of the former route of the Ermita strem to enhance infiltration. Essays and monitoring in the site of study showed that in areas were the aquifer was more than 3m deep, infiltration was more effective. Literature lists favourable conditions for aquifer recharge: scant vegetation, permeable or fractured soil, high water table level, and aboundant rainfal (De Vries and Simmers, 2002). Inflow volume 0,379999995231628 Inflow volume unit m3/sec Design contractual arrangement Arrangement type Responsibility Role Comments Name Design consultation activity Activity stage Key issues Name Comments Design land use change Land use change type Design authority Authority type Role Responsibility Name Comments Other Initiation of the measure Ministry of Agriculture, Food and Enviromental Affairs, Spain The ministry responsible for environmental affairs. Other Initiation of the measure Castilla y León Regional Government (Agriculture and Livestock Office) Is the regional authority for agricultural affairs. Other Tragsa Type: Public Company Role: Tragsa has been involved since the begining is most of the stages: Initiation of the measure; Determination of design details of the measure, Implementation, Financing (from 2007 to 2010) and Monitoring. Local water authority Other Duero River Basin Authority Supporting tragsa withdata collection and providing information. Other Universidad Complutense de Madrid Type: education and research institution Role: monitoring and field research Farmers Monitoring Irrigators Community Framers were actually involved in all the process. They were responsible for opening and closing the recharge devices following Tragsa instructions. Lessons, risks, implications... Key lessons - It is important to involve irrigators in the process and the implementation of measures, especially to those Communities that use underground waters, since the withdrawal control is lower than for those using surface waters. - It is important to improve economic and geopolitical indicators, apart from the hydrogeological ones, prior to the implementation of new devices. - Monitoring is key to improve effectiveness, to improve the devices and to increase infiltration rates and the total volume infiltrated to the aquifer. - Some key actions to ensure the proper functioning of the measure is the pre-treatment of water, the inflow regulation, reduction of suspended soils and air in water. Is advisable to avoid whipping of recharge water. Low flow speed is preferred. - Some of the most common limitations are soil silting and increase of trapped air in the aquifer, which can be avoided with SAT techniques and the proper design of the channel. Success factor(s) Success factor type Success factor role Comments Attitude of relevant stakeholders main factor Public participation secondary factor Attitude of decision makers secondary factor Successful coordination between authorities secondary factor Communication activities secondary factor Existing staff and consultant knowledge main factor Financing Financing type Comments National funds The Ministry of Agriculture, Food and Environmental Affairs. Sub-national funds Castilla y León Regional Government (Agriculture and Livestock Office) Other European Agricultural Guarantee Fund Other Trasgsa (public company) financed an RTD programme (2007-2010) to continue the research activity regarding aquifer management activities. SEPI Group (Spanish Society of Industrial Participations) was the main shareholder Barrier Barrier type Barrier role Comments Lacking financing sources main barrier The lack of financing actually became a barrier during the recharge cycles 2010/2011 and 2011/2012, when maintenance, new infraestructures and expansions were not possible, and the little activity that remained was thanks to private efforts (of researchers and irrigators) Existing technical standards secondary barrier During the progress of the implementation silting was one of the major problems which reduded efective infiltration of water into the aquifer. Several studies were carried out in order to define best solutions and improve effectiveness of the measure. Legal obligations / restrictions secondary barrier A "spill" authorization is needed to implement this measures in Spain (despite the fact that most activities result in an increased groundwater quality) Driver Driver type Driver role Comments Balancing different objectives main driver A group of groundwater users posed their concern about the aquifer degradation to the local authorities, which enabled a serie of interventions. Public pressure main driver Organisation committed to it secondary driver Financing share Financing share type Share Comments Policy, general governance and design targets Policy description The exploitation of the superficial aquifer, mainly for irrigated agriculture, has led to a 10 m fall of the water table, which has led to related salinization and pollution processes. [WFD pressure: 3.1 Abstraction, Agriculture] Part of wider plan 0 Policy target Target purpose Groundwater Recharge Increase Water Storage Policy pressure Pressure directive Relevant pressure Policy area Policy area type Policy area focus Name Comments Policy impact Impact directive Relevant impact Policy wider plan Wider plan type Wider plan focus Name Comments Policy requirement directive Requirement directive Specification Socio-economic Costs investment information See total cost Costs operation maintenance 3000 Costs operation maintenance Each recharge cycle had maintenance works of the channel and basins depending on the results of the previous year. However, there is not a specific budget with details on these specific costs. Costs total 4608946 Costs total information Initial investmentuntil 2006: Water intake: 409657 € Transfer conveyance: 2641615 € Recharge channel 1: 289940 € Recharge channel 2: 606867 € Investment in the second period: 660867€ (The amount was devoted to maintenance, studies and projects) Compensations annual information There is no specific records of compensation payments to landowners or irrigators affected by the measure. In fact, the implementation of the measure was originated from a social claim to recover a damage aquifer, and irrigators and landowners were involved in the petition. Information on Economic costs - income loss In very wet years, agricultural fields (generally with potato crops) have been occasionally flooded after the groundwater level reached the limit that should not be exceeded in aquifer managment and recharge practices (defined in 1.5m by Fernández Escalante, 2005). Ecosystem improved biodiversity 1 Information on Ecosystem improved biodiversity The implementation of the measures also included the restoration of La Iglesia lagoon, which has served as a refuge for bird life and as a nesting area. Ecosystem impact climate regulation No information available Information on Ecosystem impact climate regulation Not specific impacts are described in the literature on the case study. Biophysical impacts Retained water 2555000 Retained water unit m3/year Information on retained water Average value per recharge cycle calculated on the basis of the data obtained after 8 effective recharge cycles. Of the total volume derived to the infiltration devices, that is the volume that was actually infiltrated into the aquifer in each of the cycles in which the measure was working. Values obtained per cycle: 1300000 m3 (cycle 1; 2002/03); 1800000 m3 (cycle 2; 2003/04); 970000 m3 (cycle 3; 2004/05); 3560000 m3 (cycle 4; 2005/06); 12190000 m3 (cycle 5; 2007/08); 460000 m3 (cycle 6); 2500000 m3 (cycle 7; 2008/09); 640000 m3 (cycle 8; 2009/10); 2130000 m3 (cycle 9; 2010/11); 0 m3 (cycle 10; 2011/12). Information on increased water storage For each cycle of recharge was calculated the volumen of water devoted and the actual recharged volume. The following are the percentage of used volume vs recharged volume: 37,14% (cycle 1); 80% (cycle 2); 76,98% (cycle 3); 69,67% (cycle 4); 96,13% (cycle 5); 87,41% (cycle 6); 64,50% (cycle 7); 90,46% (cycle 8); 68,03% (cycle 9); 0% (cycle 10). Increased groundwater level 1,23000001907349 Information on Increased groundwater level Average value per recharge cycle on the basis of the the data obtained after 10 recharge cycles (and excluding cycle 6 value -see later-). These values show the variation in the groundwater level in the monitoring network. The value of the Cycle 6 cannot be only attribuible to the recharge as there was also abundant precipitation that year, and measurement could not differ between sources. Values obtained per cycle: 2,30 m (cycle 1); 2,10 m (cycle 2); 1,17 m (cycle 3); 3,36 m (cycle 4); 0,31m (cycle 5); 3,57*m (cycle 6); 0,62 m (cycle 7); 0,41 m (cycle 8); 0,54 m (cycle 9); 0,28 m (cycle 10). Information on Water quality overall improvements The hydrochemical evolution of groundwater has shown improvement in nitrate concentrations (which were very high at the beginning: 274 mg/L in the NE of the aquifer). On the other hand, some negative impacts occurred like the increased concentration of diluted iron in central-eastern areas of the aquifer, the creation of a reducing environment with calcium carbonate precipitation, and formation of imprevious crust. Soil quality overall soil improvements Not relevant for this application Information on Soil quality overall soil improvements Soil is relevant for this applicationonly regarding infiltration rates. Once the recharge has began, silting is one of the major constrains in terms of infiltration reduction. This is why Soil Aquifer Tecniques are applied in the channel /soakways and in the infiltration basins. Full Context Collection(aka Doorway or Gallery) Case Studies Pathway(aka Context) Default view Area(aka Level or Site) ALL