Innovative project underwater drainage in progress in peat polders




The farmers of the Lange Weide polder in Driebruggen are installing a 450 km long subterranean pipe system, with which they will keep their pastures moist and prevent the degradation of peat. The province enables this project financially.

Amid great interest, Regional Minister Rik Janssen, member of a water authority board Bert de Groot (Stichtse Rijnlanden) and Mayor Christiaan van der Kamp (Bodegraven-Reeuwijk) placed the first pipe on Thursday 30 August 2018. Regional Minister Rik Janssen: “The degradation of peat leads to considerable social costs. Large amounts of greenhouse gas are emitted in the process, which increase the global warming, and the cost of keeping the peatland pastures fit for agriculture is rising all the time. Taking no action is not an option. It is good that the entrepreneurs of the Lange Weide polder themselves have taken the initiative to slow down the subsidence, and we gladly support this initiative.”

Greenhouse gas

Many pastures in Zuid-Holland are located in peat areas. To be able to work the land properly and to have cattle graze, the groundwater level there may not be too high. A disadvantage of a low water level, however, is that the peat degrades, during which large amounts of the greenhouse gas carbon dioxide (CO2) are emitted. Dutch peat areas currently emit around seven megatons of CO2 annually – about four percent of the total emissions in our country.

Subsidence

By means of the subterranean pipes currently being installed in the Lange Weide polder, water can be introduced into the soil in a targeted manner. The soil will then always be sufficiently moist, and yet remain solid enough for agricultural purposes. It is the first time that this technique is used on such a large scale. Earlier tests showed underwater drainage slows down subsidence. That allows for more time to develop other techniques and possible solutions to withstand the degradation of peat and of subsidence. The ultimate approach requires customization and will vary for each area.

Subsidy

The construction of this ‘underwater drainage’ system is an initiative of 28 landowners – of which 13 are farmers – united in the farmers’ collective Lange Weide. They collaborate on this project with water authority De Stichtse Rijnlanden.  The province enables this project financially by granting 1.1 million Euro in subsidy from the European Rural Area Development Fund POP3.