"The expanse of groundwater in these deposits when they are well developed can constitute a large reserve which absorbs the variations of water flow. Alluvial deposits act rather like sponges which absorb surplus water before releasing it later. In these alluvial areas part of the water follows the course of the river: this drainage can represent a large volume. This water has been filtered, has a more constant temperature and constitutes a reserve of good quality water."
Now people are trying to save and protect wetlands because we understand why they are important."
- Many animals depend on wetlands for some part of their life cycle, like fish, frogs and mosquitoes.
- Wetland plants are very productive and support a rich web of life, from simple molds to mammals.
- Wetlands provide shelter and food for fish.
- Wetlands provide flood control by soaking up the water that falls as rain. Wetlands also slow the spring snow-melt run-off.
- Wetlands make the water clearer and filter out things that make the water impure, like chemical pollution.
- Wetlands are a wonderful place to visit, look, and listen, learn and experience life.
"Wetlands improve water quality as they are very good natural filters, trapping sediments, nutrients (e.g. nitrogen and phosphorus), and even pathogenic (disease-causing) bacteria. In addition, pollutants such as heavy metals (e.g. mercury, lead) and pesticides, may be trapped by chemical and biological processes. In other words, the water leaving the wetland is cleaner than the water entering it."
"Wetlands are filters where sediments and nutrients accumulate, so many plants grow there, e.g. bulrushes, grasses, reeds, waterlilies, sedges and trees. The plants, in turn, provide food and a place for attachment and shelter for many creatures. There is more life, hectare for hectare, in a healthy wetland than in almost any other habitat. These productive places support huge numbers of insects, fish, birds and other animals. Some animals are completely dependant on wetlands, whilst others use wetlands for only part of their lives. The wattled crane, for example, is dependant on wetlands for breeding. The rich diversity of waterbirds in southern Africa (totalling 130 species) is possible because of the many wetlands spread across the sub-continent. The wetlands of southern Africa are of international importance as they are the southern destination for many migratory wading birds."
"Wetlands have been used for centuries as grazing for domestic stock, and as a source of reeds used for thatching, hut construction and basket weaving. They are provide fishing, hunting and the opportunity to observe wildlife, especially birds. Wetlands are appreciated for their beauty as open spaces and also for their educational value."