Drought in Flanders – Challenges and new opportunities for water reuse
For the fourth consecutive year, Flanders, The Flemish Region of Belgium, is suffering from the consequences of a drought that affected the region from mid-March to mid-June. The availability of water during the spring season is very important for nature and for agriculture, as this corresponds to the period of crops germination. The analysis of precipitation data in the region over the past 15 years reveals that climate change is increasingly affecting the region with ever dryer spring seasons, with periods of low rainfalls lasting until September, while the rest of the year sees higher precipitation. This increase of drought periods presents major challenges to the regions’ drinking water companies. The groundwater levels are declining and surface water intake can be problematic. Additionally domestic rainwater reservoirs are getting empty, causing an increase of drinking-water consumption, especially when drought coincides with warm periods.
Over the years, water reuse proved to be an effective solution for the Intermunicipal Water Company of the Veurne Region (I.W.V.A) to preserve the region water resources and overcome these drought periods. Through the recycling of municipal wastewater at the Torreele Water Production Centre (WPC) where effluent from the Wulpen wastewater treatment plant (managed by Aquafin) is extensively purified, and subsequently infiltrated into the dune aquifer of St-André at Koksijde, the groundwater levels could be kept at a sufficient level to supply drinking-water to customers. This solution also preventively counteracts the effects of the expected sea level rise. In recent years the infiltration capacity of the site increased and the efficiency of the Torreele WPC was enhanced by reusing the backwash water from the ultrafiltration process. The additional treatment of the concentrated effluent from the WPC is also planned. For this a natural system, based on willows, will be used. This project, part of the EU project FRESH4Cs (2S06-028), is co-financed in the framework of the Interreg 2 Seas Mers Zeeën 2014-2019 Programme.
In view of the Torreele WPC success, last March, the neighbouring company Farys have launched a new WPC in Oostende. The site treats brackish surface water from the canal Brugge-Oostende. The techniques used are similar to those used at the Torreele WPC, including ultrafiltration followed by reverse osmosis, but with the addition of an activated carbon treatment barrier followed by a marble cascade to adjust hardness and pH.
Oostende Water Production Centre (WPC) – Pictures courtesy of Farys, Belgium.
Currently all Flemish companies are collaborating on different water reuse projects to ensure the production of drinking-water under all circumstances. These projects include the desalination of river water in Antwerpen by Water Reuse Europe member Water-link. IWVA and De Watergroep, also members of Water Reuse Europe, are collaborating with Farys in the Nieuwpoort area. In the lock complex of the Ganzepoot in Nieuwpoort, water is drained to the sea. In winter and during wetter periods, fresh water will be available and treated to drinking-water quality. This will be combined with aquifer storage recharge (ASR). In the summer, brackish water will be used as a source to produce drinking-water and supplied together with the ASR water. On a smaller scale the Municipality of Koksijde and the IWVA are collaborating to send a mixture of UF and RO filtrate to the local Golf course for irrigation purposes. This will avoid the usage of drinking-water for turf irrigation.
Emmanuel Van Houtte
Geologist, Intermunicipal Water Company of the Veurne Region (I.W.V.A)