Lakes, pounds and rivers
Champagne Humide, with it's mainly clay subsoil, offers a very large diversity of aquatic millieu and wetlands. There are two large groups : stagnant water and running water.
The lake reservoirs (4,500 ha ) are intended for the protection of the Paris region against flooding and a support for the minimum water level of the Seine in periods of drought. The creation of these totally artificial millieu has however allowed the installation of a large numbers of species of animals and plants whose lives are entirely influenced by variations in the water level.
In the Middle Ages, Champagne Humide, the heart of the Park, was an unhealthy marshy area. Important work was undertaken by Cistercian monks in these uninhabitaed areas. They built many chains of ponds that allowed them to drain the marshes and breed fish. The ponds here now are those that survived the campaign of draining undertaken at the time of the French Revolution.
Today there are about a hundred ponds all in private hands in the Park. They cover about 400 ha.
Forest and prairie pools were very often used in Champagne Humide for watering livestock. In Champagne Crayeuse, their presence provided water reserves in case of fires. Many pools were created for industrial needs such as the extraction of peat or clay, or were used by hemp and flax makers. Today, technical progress and changes in agriculture make them often useless or a nuisance so they are abandoned or filled in .
However there are still more than 300 pools in the Park with uses that have evolved generally towards pleasure .
The Forêt d'Orient Regional Nature Park is included in the upstream stretch of the catchment basin of the Seine.
In the Park, running water includes springs and forest brooks that can be permenant or temporary, as well as rivers of different sizes.
The valleys of the Aube and the Seine have brought with them sand and gravel that's very useful in building work. They've been extracted commercially for about fifty years.Gravel pits are the result of their extraction in these alluvial valleys. The water table has been reached and the pits have been flooded.Today most of the gravel pits have been refilled after use but there are still more than 200 in the Park. They are, most often, small and cover about 160 ha .