Germany – Engineering design services – Gewässerausbau Frankenthaler Terrasse Belchgraben Nord (Planfeststellung)

Project Description Measure Belchgraben Nord (Permitting): The planned watercourse section of the Belchgraben begins in the north, south of the Lambsheim sewage treatment plant, and ends in the south, above the crossing of the A61 (km 1+250, see location plan B-1.2.1 and B-1.2.2). The ditch G3 is included in the planning for the drainage of agricultural areas. The project aims to achieve water management, nature conservation, and landscape management goals. For a better overall overview, the measure is divided into three sections, summarized, and described below. For a detailed explanation of individual measures, it is recommended to read the permitting decision (PFB) of 13.10.2020 and the approval planning, particularly the volume 2 "Technical Planning." If additional work arises due to lack of knowledge of the approval planning or conditions of the PFB, we cannot accept or approve these.

Section 1: Expansion of Belchgraben (Stationing 0+230 – 0+450)

In Section 1, retention volumes are created, the hydraulic longitudinal gradient is established, and hydraulic bottlenecks are eliminated. Additionally, a ditch section will be filled in, and a new meandering ditch course (0+250-0+750) will be created, alternating with shallow water areas or gravel bars. Furthermore, a securing measure with a concrete saddle for the gas pipeline (Creos) is to be implemented at Station 0+447. Additionally, archaeological preliminary investigations are taking place in this area. As part of the expansion of the BAB 61 by the company DEGES, the farm road and the culvert at Station 0+250 will be constructed later and are not part of the execution planning.

Section 2: Expansion of Ditch G3

In Ditch G3, the hydraulic longitudinal gradient is established, and hydraulic bottlenecks are eliminated. Ditch G3 is crossed by a gas pipeline (0+125 Creos) and, in the future, a concrete saddle will be installed to secure the gas pipeline. Additionally, other media (e.g., Pfalzkom fiber optic cable) must be considered, and a sprinkler line must be secured. Furthermore, three drainage lines (approximately at Station 0+261, 0+762, and 0+940) flow into Ditch G3 further south. The exact location must be determined, protected constructively by relief structures (Plan B-2.1.2), and located. At Stationing 0+045, a DN200 sprinkler line made of ductile cast iron crosses the ditch. This line must be relocated to enable the lowering of the bottom and coordinated in advance with the Water and Soil Association for the irrigation of the Vorderpfalz. Additionally, the farm roads south and west of the ditch must be newly laid out to the side of the watercourse strip.

Section 3: Belchgraben (Stationing 0+450 – 1+250)

In Section 3, the hydraulic longitudinal gradient is also established here, and hydraulic bottlenecks are eliminated. Additionally, a relief structure for the inflowing drainage lines in the Belchgraben must be constructed at Station 0+489. At Stationing 0+953, a new sluice structure including operating instructions for the new ditch West towards Eppstein must be installed. The structure and operating instructions for regulating the sluice must be worked out and approved with the responsible authorities. Furthermore, a securing measure on a Creos gas pipeline with a concrete saddle is carried out at Station 0+192, similar to Sections 1 and 2. Additionally, the measure in this area includes the adaptation of two culverts. Table 1 summarizes the measures on the structures and their existing and planned dimensions.

Table 1: Structural Adaptations with Planning and Existing Dimensions

Watercourse Stationing Measure Dimension Planning Dimension [m] [km] [m]

G3 0+045 Adaptation Culvert BxH = 0,7x0,7 DN400

Belchgraben 0+920 Demolition Culvert unknown -

Belchgraben 0+953 Adaptation Culvert BxH = 1,99x1,5 BxH = 1,4x1,5

The entire measure is shown in the approval plans (B-1.2.1-B.1.2.4).