EPTB Seine Grands Lacs
By extension, the term "Grands lacs de Seine" also refers to all the artificial lakes in Burgundy and Champagne-Ardenne, built and managed by this establishment.
[1] EPTB Seine Grands Lacs is currently working on a project to build a new structure in the Bassée area (Seine-et-Marne), designed to complete the flood protection system and reduce the foreseeable damage associated with these phenomena.
Its mission is to increase the flow of the Seine and its tributaries during low-water periods (to ensure the water resources required by the Paris conurbation[4]) and to protect the Île-de-France region from flooding by means of the lake reservoirs it manages.
It is governed by a Board of Directors comprising 24 members (12 for Paris, 4 for Hauts-de-Seine, 4 for Seine-Saint-Denis and 4 for Val-de-Marne), appointed by the general councillors of these departments.
The institution was chaired from 2001 to 2012 by Pascal Popelin, then First Deputy Mayor of Livry-Gargan and vice-president of the Seine-Saint-Denis General Council.
List of lake reservoirs managed by EPTB Seine Grands Lacs, in chronological order of construction.
[9] "Lake of Orient" or "lac-réservoir Seine" is located in the Aube region of Champagne-Ardenne, a dozen kilometers from Troyes.
Deriving from the Marne and one of its tributaries, the Blaise, the lake owes its name both to the Pays du Der, the natural region in which it is located, and to the village of Chantecoq, which was destroyed along with those of Champaubert-aux-Bois and Nuisement-aux-Bois when it was created.
In winter and spring (November to June), the reservoirs are progressively filled, either via the inlet canals or the dam, since rivers are at their highest during these periods.
[20] In the event of winter drought, the lakes may have to reduce their catches sharply, thus making a compromise with the need to store water for the summer.
[22] In 1995, another study carried out by the IIBRBS and the Agence de l'Eau Seine-Normandie showed that, without the reservoirs, the Île-de-France region would face shortages of potable water on several days of the year.
[23] The environment was profoundly transformed by the construction of these structures, as was the landscape: many hectares of forest were destroyed to build the lakes.
They alter the hydraulic regime of rivers, making certain spring floods impossible, even though they are essential for northern pike reproduction.
In addition, the Lac de Pannecière prevents the free movement of trout, limiting their reproduction downstream of the dam during the winter.
[24] The three Champagne-Ardenne lakes have been recognized by the Ramsar Convention since 1991, as part of the "Étangs de la Champagne humide" site.
[28] In addition, every year, over 1.5 million visitors flock to the Seine's grand lacs and their infrastructure, including marinas, cycle paths, hiking trails, beaches, and observatories.
[30][31] The estimated cost of the pilot reservoir alone represents more than three-quarters of the total 110 million euros of the flood prevention action plan.
With a possible surface area of 2,300 ha and a capacity of around 130 million m3, it would be built on the principle of other lakes: earthen dykes surrounding a body of water.
