Thanks to this rigorous plan, you will soon no longer be bothered by blue-green algae at the Noord Aa

Want to take a refreshing dip in the water at the Noord Aa every summer without any problems? That sounds like music to your ears! That dream could easily become reality in the coming years. The municipality of Zoetermeer and the Rijnland Water Board have big plans to improve water quality with a reverse water system. Blue-green algae can therefore disappear like snow in the sun.

Every year the question is how long we can enjoy the beach and the refreshing water at the Noord Aa. Blue-green algae regularly ruins Zoetermeer residents’ summer outings. With a new plan, the municipality and the water board not only want to reduce blue-green algae, but also work on vibrant banks with diverse plants and animals.

Blue derriere

Blue-green algae is a bacterium that develops in poorly flowing water with many nutrients and in persistently warm weather. It makes water cloudy, making it difficult for animals and plants to live in it. The bottom layer of accumulating floating layers of blue-green algae will rot, turn blue and cause a bad smell. Swimmers and water sports enthusiasts should not go into the water because the bacteria causes skin irritations and stomach complaints, among other things. The blue-green algae regularly occurs every summer in the Zoetermeerse Plas, which means we cannot swim at the Noord Aa.

Bathtub thirty meters deep

To understand the origins of blue-green algae in Zoetermeer, we simply explain how it works. De Leyens pumping station pumps the water from the city, and from agricultural areas, to the Zoetermeerse Plas. This water contains many nutrients, such as phosphates. The pool is shaped like a bathtub into which the nutrients sink up to 30 meters. It just so happens that the blue-green algae love those phosphates. Conclusion: too many nutrients enter the lake, causing the blue-green algae to live in a nutrient-rich environment. In the meantime, the water quality is deteriorating, meaning that animals and plants have little to do there and we cannot swim there in the summer.

Blockages under your feet

In addition, there are underground water connections on the street beneath your feet. These connect Zoetermeer ditches and ponds with each other. Some connections are up to 400 meters long! Dredged material and dirt cause blockages, turning the water into a dark, cloudy and oxygen-poor mess through which fish cannot swim. The water quality here is downright awful.

We’re turning things around

As a solution to this blue-green algae problem, the municipality and Rijnland have come to a rigorous decision: to improve the water quality in Zoetermeer, they turn around the water system. This means that the water no longer goes to the Zoetermeerse Plas but to the Nieuwe Driemanspolder. This relieves the water at the Noord Aa and the water quality improves over time. Due to this choice, the Driemanspolder pumping station has to work hard, but the De Leyens pumping station is going to take it easier. Only during heavy rainfall does the De Leyens pumping station pump away the excess water.

Two new waterways

To reverse the water system, two additional waterways are needed. The open waterways will be located in the Westerpark and the Bossenpark in the Meerzicht district. Rijnland will start work on the culverts, bridges, cables and pipes at both locations in the spring. The municipality is planting new plants and trees around the new banks. Nature must develop slowly, so that more and more insects and animals will find their place along the banks. With a lot of patience, the water quality will improve and we will eventually be able to swim at the Noord Aa without any problems.

Source: onsblauwgoud.nl