8. Case studies

Netherlands

The Netherlands rely by 60% on groundwater for drinking water supply and 100% in dry periods for irrigation needs (NWP. 2007). Despite this increased reliance of the Dutch water sector to groundwater resources, groundwater bodies were reported to have a good quantitative status in all four Dutch River Basin Management Plans. The country’s main response to decreasing groundwater resources is the recharge of river water in dune infiltration ponds and wells. This measure has been in place for the past 50 years for securing drinking water supply to Amsterdam, The Hague and many other cities (NWP. 2007).

In the water management district "Waterschap Groot Salland" (82,000 ha) located in the Dutch part of the Rhine river basin, the quantitative status of two groundwater bodies was assessed with the use of four tests : water balance, saline intrusion, aquatic ecosystems and terrestrial ecosystems.

In these water bodies are situated two major groundwater dependent terrestrial ecosystems, designated as Natura 2000 sites, the ‘Boetelerveld’ (173 ha) and the ‘Olde Maten and Veerslootlanden’ (993 ha). These natural ecosystems mainly consist of marshland, the development of which is due to the impermeable layers of underground geologic formations that block the drainage and form wet land.

The research on the quantitative status of the two Groundwater bodies led to the following conclusions:

• In terms of water balance the good status of the Groundwater bodies is not affected because of a surplus of net precipitation.
• Salt water intrusion in the Groundwater bodies is controlled and thus prevented by permanent ‘early warning’ monitoring systems and therefore does not affect the good status of the Groundwater bodies.
• The surface water bodies in the Groot Salland district, mainly man made watercourses for purposes of drainage and flood protection, were formed during the 1960s and 1970s and their ecological objectives (MEP/GEP) are determined by the quality of the Rhine water led in during dry periods. Thus, the quality of surface waters in the area is not significantly dependent on the supply of groundwater and so the good status of the Groundwater bodies is not affected.
• In both groundwater dependent terrestrial ecosystems measures in order to raise the groundwater table have been taken, e.g. the filling of the ditches and the construction of a canal in 2000 with high water level in the Boetelerveld in order to retain more precipitation. It was confirmed that drinking water abstractions elsewhere in the Groundwater bodies did not have an important influence on the groundwater table in these two Natura 2000 areas. Concluding, since 2000, when the WFD came into force, the hydrological conditions in the two areas remain stable and are considered to be sufficient for preserving the two Groundwater bodies in a good status.

Spain

Catalonia is divided in two river basin districts which include a total of 53 groundwater bodies. According to the Catalan Water Agency, 21% of groundwater bodies are at risk of non-compliance with the Directive objectives for groundwater quantitative status. These groundwater bodies are mainly affected by overexploitation for domestic public water supply in densely populated areas. This overexploitation creates an imbalance between the available and required water and allows saline intrusion in many groundwater bodies of the region. For addressing this issue, the Catalan Water Agency promotes the substitution of groundwater abstraction with other sources, such as water discharged from tertiary waste water treatment plants and desalination plants. In addition, the Catalan Water Agency is also considering the use of treated and desalinated water for artificially recharging groundwater bodies. This response has reversed the effect of overexploitation in the two pilot groundwater bodies where it was implemented. (Ninerola and Ortuno, 2008). 

Italy

The reported River Basin Management Plans, for Italy’s six River Basin Districts, identified that 53% present a good quantitative status, 16% a poor quantitative status and the status is unknown for the remaining 31% of Italy’s groundwater bodies. Italy’s groundwater bodies quantitative status is mainly caused by overexploitation, failure to achieve environemental objectives for surface waters and saline intrusion. Overexploitation of groundwater resources occurs mainly in the large urban areas of northern Italy, the tourist areas of the coasts of Romagna and Toscana, large industrial areas and densely cultivated areas such as the valley of the river Po. Italian authorities’ main response to overexploitation is the monitoring of all groundwater abstractions and the prohibition of abstraction to all unmetered abstraction points. Furthermore, Italian authorities have initiated pilot programmes of groundwater recharge in areas of Piedmont and planned for areas in Toscana and promote the replacement of groundwater with re-used and treated water mainly for industrial and irrigation purposes (EASAC, 2010b).