Baseline for sustainable stormwater management: first findings from the surveys

BSR WATER platform project is conducting a survey on stormwater-related legal review and implementation of sustainable urban stormwater management in the Baltic Sea Region cities.

Due to the climate change Baltic Sea Region (BSR) is facing more frequent and heavier rainfalls, most heavily affecting densely built and inhabited urban areas. Therefore, cities are in emerging need to deal with the common challenge of stormwater flooding – a challenge that may lead to environmental degradation, infrastructure damage, risks to human safety and other adverse impacts to urban environment. Such challenge is not easily answered as it requires a holistic, comprehensive and knowledge-based approach to stormwater management.

With the aim to better understand the baseline and other pre-conditions for setting up a sustainable stormwater management in the region, the BSR WATER platform is conducting a comprehensive survey on stormwater-related legal review in 11 BSR countries. In parallel, the project is carrying out structured interviews of 35 medium and large-sized cities of the region, assessing their current progress with urban stormwater management improvements, needs and future development prospects.
 

Stormwater legal review

Stormwater-related legal review ascertained that in all BSR countries national legislation sets out quality requirements for wastewater treatment and monitoring, thus ensuring that the surface water bodies and groundwaters are kept in good condition. However, in majority of the BSR countries binding regulations refer only to those stormwaters entering the sewerage systems, either combined stormwater and household wastewater systems or separate, pipe-based stormwater drainage systems. Thus, none, or not enough attention is paid to open, nature-based, on-source stormwater drainage solutions. Only in a few forerunning countries (e.g., Denmark, Germany, Sweden, Finland) national legislation provides detailed requirements for stormwater treatment, irrespective of the type of stormwater drainage system.

Furthermore, the municipalities of Copenhagen, Berlin, Malmö and Helsinki have adopted binding rules and guidelines for stormwater drainage and treatment, among other, prioritizing infiltration and retention of stormwater at the source, contrary to conventional practice to convey stormwater into wastewater sewers, paying much attention to tackling extreme storm events and to mitigating the effects of climate change.
 

Approaches and tools for stormwater management

BSR cities that were interviewed on issues related to introduction of sustainable stormwater management approaches and tools, highlighted the importance of this topic in entire urban planning system – all interviewed cities admitted the need to implement integrated stormwater management and sustainable stormwater planning in near future. Although the awareness of these concepts is high, adoption of approaches, tools or solutions in majority of cities is rather slow – mainly due to lack of common understanding and mutual collaboration among different municipal structures responsible for stormwater issues, non-existence of mutually agreed goals, insufficient or inappropriate financing schemes for stormwater management, insufficient knowledge, lack of local stormwater experts and many other obstacles. Majority of cities recognized the need to inform and educate politicians and other decision makers on wide benefits of sustainable stormwater management.

New policies, binding targets and generous incentives are needed for transition to sustainable stormwater management

The key findings of the survey suggest that existing stormwater management policies in the region to great extent are recommendatory, and thus can be considered as sufficient enough to justify the will of forerunner cities to improve their existing stormwater planning and management practices. However, for the majority of the BSR cities, as the prerequisite for transition to sustainable stormwater planning and management, new policies, binding targets and generous incentives must be in place, supporting the implementation of innovations in stormwater management and, among other, promoting and prioritizing on-site stormwater treatment approaches that improve urban environment, contribute to urban ecosystem services and thus have crucial role in increasing cities’ resilience in the context of the climate change.

Nika Kotoviča
Riga City Council