Flood retention basin at the river ditch (Neumarkt i.d.OPf) Landscape management plan (LBP) with special species protection assessment, preliminary assessment (saP) with ecological construction supervision

Due to the conversion of two intensively used fish ponds into flood retention basins, the course of the brook was returned to its original course over a distance of approx. 250 metres. Previously, the stream ran through the fish ponds and the still recognizable course through the floodplain forest was only flowed through in the event of a flood. Natural spring outlets, whose water was previously channelled into the ponds, are now directly connected to the course of the stream.
The intensive use of the fish ponds with sedimentation and grazing has been abandoned and deconstructed. This has moved the use further away from the creek. The danger of nutrient-laden water entering the stream has been eliminated.
Another fish pond (with impoundment, monk) has been converted to amphibian water. Still waters in this landscape area, which is characterized by karst phenomena, are scarce. Therefore, the upgrading of this water body with flattened, sunny banks as an optimised spawning ground is all the more important. The overflow next to the monk (so that the water level in the pond remains controllable) has been set up as a rough bottom ramp or slope for a variety of creatures (similar to a fish ladder). The concrete drop-off has been deconstructed, bank revetments have been removed and flattened accordingly, and the water level has been lowered. The stream continues to run through the pond here. As a result of the reconstruction, the entire section of the stream along the three fish ponds is now once again passable for living creatures.

The floodplain has been designed as close to nature as possible at the lowest possible points of intervention by enriching the course of the stream with structures such as stones, dead wood and old rootstocks. The artificial fills, including building rubble and nutrient-rich soil from former garden use, where mostly neophytes are found, have been removed. Garden use, on which mostly neophytes (such as skipping weed, Impatiens glandulifera) and monotonous perennial communities (stinging nettle and blackberries) grow, were largely dug up. Fishpond and recreational use huts and debris along the creek were removed. During construction, a fenced concrete manhole was removed and exposed as a semi-natural spring. Within the first year of completion, numerous common toads and frogs successfully spawned in the newly created water body.
The diffuse seepage springs located to the west of the large flood retention basin were also optimised as amphibian spawning waters. To this end, the depressions were widened and pools were created.
In the wooded fringe along the watercourse, consisting predominantly of alders, numerous non-site-typical woody plants such as spruce and Douglas fir were introduced, which were cleared at the beginning of the construction work in the winter half-year. In this way, the floodplain forest was reactivated so that a site-appropriate plant community could develop. Pulled rhizomes from the constructed pools were deposited in the area as additional structural enrichment.
The bottom of the flood retention basins was grassed over using a hayrush method. By the fall of 2017, the area had already been developed as an extensive wet meadow and closed to the point that no woody vegetation could approach. Next year, the area will be mowed and transferred to a maintenance concept. The permanently water-bearing depressions in the basin bottom were also filled with water during dry periods. Embankment areas that were seeded with autochthonous seed also quickly greened up.
The planting at the base of the embankment along the federal highway as a screen and guide was established with shrubs appropriate to the site. Large style oaks were planted.