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Water Solutions

Close-up: the Freshmaker’s value during the late Summer drought of 2016

Related Work Package: 1.2
Keywords : Freshmaker, SWS, Subsol, Ovezande, 2016

Construction of the river bed filtration system in 2014

 

Production of the Freshmaker in 2016.

 

It was a typical El-Nino summer in The Netherlands, this year: a wet spring and wet start of the summer, but a magnificent late summer with high temperatures and hardly any rainfall. Not a perfect late summer for the Rijk family, however, since their fruit (apples, pears) require the most irrigation water in this period, in order to attain an optimal size for their buyers.

 

Valuable

However, their Freshmaker proved itself valuable during August and September by recovering fresh groundwater from a thin freshwater lense for irrigation of their orchard. This fresh groundwater was infiltrated as treated stormwater in the winter before (November 2015 - April 2016) and was taken from the drainage canal running through their orchard. This intake was integrated with riverbed filtration (see photo), in order to remove suspended solids from the stormwater. Via a 3 m high standpipe, the water infiltrated via a 70 m long horizontal well at 7 m  depth into the freshwater lens in the subsurface. Meanwhile, brackish water was abstracted with a low rate just below the freswhater lens with a second horizontal well. The result: thickening of the freshwater lens and thus freshwater storage.

Hardly any of this stored freshwater was required during the next spring. However, in August and September, virtually all of the stored water was required for irrigation of the 15 hectares orchard of the Rijk family. The water was recovered using again the horizontal well at 7 m depth and then direcly sent to the drip irrigation system or the aboveground reservoir of approximately 3.000 cubic meters. From this reservoir, the water could be sprinkled over the orchard, which also provided cooling on the hottest days. Meanwhile, the stormwater canals were severily salinized by the domination of brackish seepage over stormwater discharge. And there was no alternative freshwater supply...

For the Rijk family, having the Freshmaker therefore tripled their freshwater availiblity in the late Summer of 2016. In crucial phases of the growing season, this makes a big difference in their fruit production. For the Subsol team it showed that the Freshmaker smoothly operated for the fourth year on a row...

 

 

Illustration of the Freshmaker (by The Waterbuffer Foundation, 2015; http://www.waterbuffer.net)