In the catchment area of the Kinzig with the most important secondary waters of Salz and Bracht, there have been repeated flood events in the past, which caused great damage in the settlement and industrial areas of the middle and lower reaches. Triggered by a flood in 2003, a flood protection plan for the Kinzig catchment area was commissioned as part of a pilot project carried out by the state of Hesse.
In the course of this, the water association Kinzig commissioned Tractebel Hydroprojekt GmbH with the planning for the construction of an ecologically continuous flood retention basin (HRB) at the main end of the water bracht at the Weilers site. The contents of the planning are the object and structural design as well as the planning of the technical equipment.
According to DIN 19700-12, the HRB Weilers/Bracht is a large basin with a total storage space of larger than 1 million m³ and a maximum height of the shut-off structure of approx. 8.50 m. The HRB is intended as a basin without permanent congestion (dry basin, so-called "green basin"). It consists of the barrier structure – a dam with an inclined seal – as well as the steel concrete passage structure with operating facilities such as the extraction facilities (operating outlets, basic drain/ecological passage), the flood relief system (dam barrier) and an energy conversion plant (as a tosst). The standard delivery is controlled at up to 48 m³/s.
In the future, the basin, in conjunction with the Kinzig Dam and other HRBs to be planned, will provide protection against hundreds of years of flood events or the lowering of the flood level of the Kinzig and its secondary waters. The current planning subject is design planning. Construction is expected to start in 2024.
Lars Schaarschmidt, Albrecht Köhler - Weimar