The Drenthe AA

Meandering streams along heathlands, hay meadows and esd villages color the iconic and historic landscape of the Drentsche Aa. A unique and extensive network of streams and tributaries in the provinces of Groningen and Drenthe. Due to the diversity in the ecosystem, the area is home to many different species of flora and fauna. Due to persistent drought and hot weather, the area suffers from desiccation in summer and nature deteriorates.

To improve the ecological quality and strengthen vulnerable nature, the bottom of the stream has been raised at three different locations in the Drentsche Aa – Zeegscherloopje, Anloërdiep and Taarlosche diep. The measures aim to improve water collection and storage for times of extreme precipitation and dry periods. Knoop BV, as a specialized contractor for natural and hydraulic engineering, was asked to come up with an innovative working method.

The challenge was in ecological vulnerability: preventing damage from transport. Consideration was also given to nearby residents and landowners, among others. The challenge was mainly in the limited bearing capacity of the soil and limited accessibility of banks. This called for an adapted implementation method to put little or no strain on the vulnerable nature. To achieve this, we developed a method especially for this project in which sand is mixed with water and spread through the stream by means of a pressure pipeline. A unique system that was the first in the Netherlands to raise the brook bed in this way. This also minimally preserved and even improved the ecological quality.