Institute for Resource Management
. .

Rain water; precipitation; urban water management; near-surface; Hamburg; organization; operator; financing; constellation analysis

Models for a new rain water management concept in Hamburg


With the new nature-oriented concept of rain water management, RISA (RainInfraStructureAdaption), the City of Hamburg aims at preparing for future events of extreme rain. Technically speaking this is feasible, but the restructuring of organizations, operation and financing bears a challenge: the responsibility for managing RISA’s near-surface drainage systems lies in the legal limbo between water and sewage management, and between private property owners, the district offices of Hamburg and HAMBURG WASSER (the municipal Water Supply and Wastewater Disposal Company). inter 3 aims at developing sound implementation models through an intense stakeholder dialogue.

Shallow rain water management: What needs to be considered?

To keep rain water on the surface, to let it evaporate or seep away instead of discharging it into the sewage system is the central idea of RISA (RainInfraStructureAdaption), a project conducted by the State Ministry for Urban Development and Environment of Hamburg (BSU), the City of Hamburg and HAMBURG WASSER. Near-surface rain water management could lead to a greener city and it could obviate an expensive extension of sewage systems for the handling of heavy rain. A pilot project is being conducted in a housing estate in the area of the former Röttiger barracks by inter 3 in close cooperation with BSU and HAMBURG WASSER. Using the constellation analysis, uncertainties, needs for regulation and other critical points are being defined.

Financing, responsibility, operation – These are the key issues

RISA aims at realizing near-surface rain water drainage not only in the pilot area but to integrate it into the general practice of urban water management in Hamburg. How do near-surface drainage systems have to be legally defined? Who has which responsibilities? And how can all this be financed? Are there interfaces or overlapping responsibilities? Who should cooperate? inter 3 will develop different scenarios to be discussed with experts and citizens in several workshops. The goal is to outline the main pillars of consistent models for organization, financing and operation and to delineate open questions and needs for rules in an organized and applicable way.

Project name:
Constellation Analysis for RainInfraStructureAdaption (RISA)

Wolf Raber Phone.: +49(0) 30 34 34 74 57

State Ministry for Urban Development and Environment of Hamburg (BSU) HAMBURG WASSER

Local partners:
State Ministry for Urban Development and Environment of Hamburg (BSU) HAMBURG WASSER

Location: Berlin

Duration: June-August 2013