Preserving good water quality is vital to our coastal environments. Every year poor water diagnosis causes hundreds of beach closures and restricted ocean access. To keep our littoral playgrounds open, healthy and clean, Surfrider Foundation Europe is launching a new program, Sea Smart Land, to reduce water pollution at the source.
Surfactants in the ocean: a major pollution, mostly invisible, except in large disgorgements, like on this photo taken in the South West of France
Upstream of pollution, the catchment area
We generally understand the water cycle at a global scale, a cycle that moves water between land and sea, up through clouds, and returning back as rainfall caught by rivers and streams. This cycle is disrupted and polluted by human activities, such as agriculture and industry, whose emissions lower water quality in downstream catchment areas. A catchment area is an area from which rainfall comes together at a single point, before joining another body of water, such as a river or lake.
An important aspect that often remains unknown is that, at the local level, the water cycle takes place within a much more concentrated space. The water cycle at the local level is characterized by the infiltration of rainwater into the soil. A process called evapotranspiration means that part of this water immediately goes back into the cloud layer that it came from, as water evaporates directly from the soil and is taken up and then evaporated by plants. The other part will go deep into the soil, where it will join the aquifers underground.
Good functioning of the water cycle on this local scale is essential. The infiltration process in the soil allows the water to be naturally filtered and purified. Once contained in the earth, groundwater acts as an essential resource for plants and humans. Additionally, the perspiration of plants has the advantage of refreshing the air and increasing its humidity.
Excessive use of concrete and asphalt in urban spaces disrupts natural cycles
Unfortunately, strong urbanization in certain areas has had a particularly negative impact on the local water cycle. The excessive use of concrete and asphalt in cities makes it increasingly difficult for water to penetrate the soil. Instead of being absorbed into the ground, rainwater is redirected along the surface of the land, taking all the pollution of our cities with it. This contaminated runoff makes its way into urban drainage systems, is moved through manmade water ways, and eventually enters the natural environment via rivers that lead to the ocean.
Water management at the local cycle level is made even more difficult during events of heavy rainfall or flood events. Overflow of sewer networks, a lack of stormwater basins (considered too expensive or too cumbersome), and insufficient functioning of water treatment plants are quick to show the limits of these water management systems. In turn, this malfunctioning significantly increases the risk of flooding and pollution in low sea level areas.
Rain gardens in an urban environment
Surfrider Foundation Europe, building on years of active interest in water quality and its flow-on effects, now takes action by launching Sea Smart Land in partnership with the NGO Bleu Versant, a team of landscapers from La Rochelle committed to improving water quality. This new project will focus on raising awareness around local water quality and the creation of urban “rain gardens”, green spaces built with strategic landscaping design to reduce soil sealing, trap polluted runoff, and restore natural local water cycles in the city.
The benefits of green spaces are numerous. They enable better infiltration of water into the ground, water basins and valleys, improve water retention, and help avoid floods during heavy rains. They also support water purification and filtration. By engaging communities in the construction and use of rain gardens, Sea Smart Land also aims to raise awareness on the importance of taking a holistic approach to water management. By working at the source with land design improvements that consider and respect catchment areas and our coastal environments, we can help to improve water quality and keep our playgrounds open for all to enjoy!
