Boufflers Pond

Etang Boufflers

The Boufflers pond is the largest of the 4 ponds of the Foundation (28 ha registered and up to 27ha of water at full capacity). Its basin, together with that of Riquet uphill, is 107 ha (45 + 62 ha).

The purpose of this pond is to be a conservatory with a reserve effect, because it is situated in the fenced park, and thus particularly favourable to water birds.

Beginning 1992, various development works have been done, the main ones are listed below:

  • Creation of islets, deepening and widening of the former fishery to create a shallow extending to the central islet (with a pit which water is cooler and better aerated for fish in the summer and also permitting to host diving ducks,

  • Piping of part of the peripheral ditch over approximately 325 metres in order to maintain continuity between pond and prairie,

  • Consolidation of the thou (valve) and dike (425 m long) with pouring of a concrete slab (30 cm thick, 425 m long (extending 5 cm below the bottom of the pond)

  • Creation of stackings and creation of peripheral ditches (before these works and in the absence of peripheral ditches, water used to flood the surrounding bushes before the pond could reach its capacity,

  • Renewal of ditches arounf the bushes uphill,

  • Realisation of ditches to the west to fragment the rush,

  • Setting up on the north-east border of four experimental basins, associated to two observation towers, realised in 1998 to do a study on competition between the european Cistude and the Florida turtle in confined basins.

The first objective of these development works was thus to have apond serving as a refuge to the ducks during the winter time. Regular water deficits combined to emptying for fish harvesting made it unattractive for water birds during winter time. Water management was reorganised and it was decided to maintain it full, and not to follow the wet/dry classical Dombes cycle, and to dispense with the fish production logic.

The Boufflers pond has thus not been emptied between 1994 and 2013.

Etang Boufflers
Etang Boufflers sous la neige

Thus, this management mode and the rehabilitation works done have been favourable to the development of diving ducks that had kept away from the pond since 1994, with among others the presence of the Fuligule nyroca (reproduction success seen for the first time in the Dombes since 1964). It was also decided to follow the evolution of the flora and fauna on its surroundings to complete the validation of the works done.

If the results obtained did initially favour water birds, some negative points have recently emerged directly linked to this management mode that resulted in eutrophisation of the pond, which brings us to reconsider the management mode.

It may be that the dry status of the Boufflers pond in 2013 after 18 years of water presence may not have been sufficient to return to the presence of herbs and helophytes that permit fish and ducks to feed.

Thus, the management plan started in 2012 aims to an emptying for fish harvest only after 5th year (with a subsequent filling with water) without extending the presence of water beyond 10 years.