Watercourse maintenance
Watercourse maintenance refers to the regularly recurring maintenance of developed and undeveloped watercourses. The type, scope and frequency of maintenance measures vary depending on the size, importance and utilisation of a watercourse and the type of catchment area.
The Landestalsperrenverwaltung (Freiberger Mulde/Zschopau operation, Chemnitz river maintenance centre) is responsible for watercourse maintenance as an obligation under public law for the 1st order watercourses (Chemnitz, Würschnitz and Zwönitz). All other watercourses (approx. 330 km) are maintained by the city's civil engineering department.
There are numerous possibilities for sustainably improving the ecological condition of watercourses through watercourse maintenance, without neglecting the protection of flow conditions.
The basic objectives of watercourse maintenance are set out in the Federal Water Act (WHG)[1] and the Saxon Water Act (SächsWG).[2] Accordingly, maintenance essentially includes
- the maintenance of the watercourse bed, also to ensure proper water flow,
- maintaining the banks, in particular by maintaining and replanting site-appropriate riparian vegetation, as well as keeping the banks free for water runoff,
- maintaining and promoting the ecological functionality of the watercourse, in particular as a habitat for wild animals and plants,
- maintaining the watercourse in a condition that meets water management requirements with regard to the discharge or retention of water, bed load, suspended matter and ice.
Maintenance measures must be limited to what is "necessary for water management". In terms of achieving the objectives of the European Water Framework Directive, watercourse maintenance has increasingly taken on a new perspective in recent years. In addition to maintaining a proper condition for water runoff, the preservation and development of the favourable effects of the watercourse on the ecosystem and the water landscape is an equally important goal of watercourse maintenance. Changes to the watercourse resulting from natural processes should be permitted where this does not conflict with other rights, thus giving the natural dynamics and development of a watercourse more room for manoeuvre.
Measures that effectively improve the ecological status of a watercourse in the long term include, in particular, keeping the watercourse edge strips free and planting site-appropriate riparian trees and shrubs.
The party responsible for watercourse maintenance is responsible for the watercourse bed and the embankment area of the watercourse. The maintenance of the riparian strip is the responsibility of the respective landowner.