The Neckarausamt Heidelberg is planning 6 weirs on the Lahn, which will replace the existing weir systems as replacement buildings. All 6 new weir replacement structures are to be implemented as a double-field, water-filled hose weir. For all systems concerned, a complete weir system with weir, including bank connection, operational building, electrical equipment and new leveling devices, must be planned. In addition to the new replacement weir, ecological consistency in the form of fish ascent and fish descent with fish protection must also be planned. Furthermore, as part of the overall contract, a uniform concept for the necessary inspection closures in the upper and lower water of the system must be developed and implemented.

The engineering services to be awarded comprise the service phases 1 to 6 according to HOAI in an overall contract and are divided into fixed and optional contract components. This results in the following breakdown of these contract components for the overall contract:

- Dausenau barrage:

—— fixed weir LPH 1-6 / fish ascent LPH 1-2 / fish descent LPH 1-2;

—— optional fish ascent LPH 3-6 / fish descent LPH 3-6.

- Nassau barrage:

—— fixed weir LPH 1-6 / fish descent LPH 1-2;

—— optional fish descent LPH 3-6.

- Hollerich barrage:

—— fixed weir LPH 1-6 / fish ascent LPH 1-2 / fish descent LPH 1-2;

—— optional fish ascent LPH 3-6 / fish descent LPH 3-6.

- Scheidt barrage:

—— fixed weir LPH 1-4 / fish ascent LPH 1-2 / fish descent LPH 1-2;

—— optional weir LPH 5-6 / fish ladder LPH 3-6 / fish ladder LPH 3-6.

- Cramberg barrage:

—— fixed weir LPH 1-4 / fish ascent LPH 1-2 / fish descent LPH 1-2;

—— optional weir LPH 5-6 / fish ladder LPH 3-6 / fish ladder LPH 3-6.

- Diez barrage:

—— fixed weir LPH 1-4 / fish ascent LPH 1-2 / fish descent LPH 1-2;

—— optional weir LPH 5-6 / fish ladder LPH 3-6 / fish ladder LPH 3-6.

This engineering contract includes the following performance profiles:

- property planning;

- structural engineering;

- Technical equipment, broken down as follows:

- Weir system: System groups 4 (high-voltage systems), 5 (telecommunications or information technology systems) and 8 (building automation);

- Fish descent facility: facility groups 4 and 8;

—— Fish lift: facility groups 4 and 8.

- engineering survey;

- Coordination of safety and health protection (SiGeKo) during the planning phase.