Nature Based Solutions - Implementation Models Database

Implementation model

DrainGarden in Ober-Grafendorf

A short description of the NBS project

The drainage of rain water in public spaces is becoming an increasing challenge for settlement areas. Increasingly frequent heavy rainfall incidents lead to surface flooding in expanding settlement areas and damage of private and public property. The adaptation of the entire drainage system - from sewer grates over pipe cross-sections, pumping stations, treatment plants and retention systems to the impacts of current and future weather conditions - represent an enormous burden of cost for municipalities. An economically attractive and ecologically valuable alternative are DrainGardens, planted with perennial vegetation or shrubs and specific substrates. DrainGardens help retain rain water locally and deliver it purified to the groundwater. This corresponds also to the objectives of the EU Commission. The plants evaporate the stored water gradually and improve the microclimate. The project “eco-street” (Ökostraße) implemented in the municipality of Ober-Grafendorf represents a smart, decentralised, ecological rainwater management system based on an environment-friendly urban street design (DrainGarden). It is a system of vegetated, aesthetically appealing roadside surface strips covered with special substrates of natural origin and planted with greenery that are able to absorb, retain, store and filter large amounts of water in short time. The specifically developed soil substrates are layered in a way as to combine high water permeability with high storage capacities. In case of heavy rainfall the water is not flowing from streets and other paved surfaces into the sewer, but into the green areas. Each cubic metre of substrate can store up to 500 litres of water. As it is required by regulations in place for conventional water retention structures, the system is designed to assure flood protection up to heavy precipitation events with a 100 year return interval. The water remains available to the plants, is filtered by the substrate and allowed to infiltrate slowly into the groundwater body. The micro-climatic effect of the water used by the plants for transpiration equates to the cooling capacity of a 100-years-old beech tree on a hot summer day and is able to reduce the local temperature by up to 5°C during heat periods. Further environmental co-benefits include the storage of CO2 by plants and substrate, the containment of growth of sealed soil, an increase in urban green spaces, and visual improvement of the townscape. The system allows the municipality to avoid investment costs for construction of additional sewage pipes as well as regular operational costs for maintaining the sewerage and operating pumping facilities. In addition, the existing urban water drainage system is disburdened, and costs for operating the municipal wastewater treatment facility as well as for irrigation and maintenance of the urban greenery are reduced. Selection of the right plant species is a crucial factor for success of the measure. Apart from being in compliance with road safety standards, the greenery should be designed as to avoid drivers and walkers from damaging the system, which can be achieved by using shrubs, flowering and soil-covering species. On the other hand, suitable plant species need to be adjusted to the local climate and should be perennial, easy to maintain and robust, including resilience against de-icing salt during winter time. The project has been designed as a scientific experiment whose performance parameters are currently continuously monitored in order to learn for future applications. The adaptation measure is particularly suited for the secondary street system in settlements and for newly developed settlement areas. With necessary modifications, the rainwater management system can be tailored to other situations, such as green roofs, car parks, and private housing. The “eco-street” concept has received much attention by both the public and experts, and it is considered an important innovation in sustainable local road construction. The municipality Ober-Grafendorf intends to widely apply the concept on its territory, therewith reducing the share of sealed surface area.

NBS Implementation context
Location Austria, Ober-Grafendorf (Austria)
Latitude
Longitude
Status Project delivered (2015-2016)
Dates
Description of the NBS
NBS Scale object (building, etc.)
NBS Impacts scale • Object (street) • Neighbourhood • City
Urban density/ Soil consumption High (dense city center)
Combined with other(s) environmental friendly solution(s)?
if other
NBS Typology
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NBS Uban Challenges
Climate Issues Climate mitigation
Climate adaptation
Other 0
Urban water management and quality Urban water management and quality
Flood management
Other 0
Air Quality Air quality at district/city scale
Air quality locally
Other 1
Urban Space and Biodiversity Biodiversity
Urban space design
Urban space management
Other 0
Urban Regeneration and Soil Air quality at district/city scale
Other 0
Resource efficiency Food, energy and water
Raw materials
Waste
Recycling
Other 0
Public health and well-being Acustic
Quality of life
Health
Other 0
Environmental justice and social cohesion Environmental Justice: Recognition
Environmental Justice: Procedural Justice
Environmental Justice: Distributional Justice
Environmental Justice: Capabilities
Environmental Justice: Responsibility
Social Cohesion
Other 0
Urban planning and governance Urban planning and form
Governance in planning
Other 0
People Security Control of crimes
Control of extraordinary events
Other 0
Green economy Circular economy
Bioeconomy activities
Direct economic value of NBS
Other 0
Other
Stakeholder and Governance
Who Started this initiative? Governments • Local government/municipality (Ober-Grafendorf Municipality)
Contracting Authority
Project manager (leader and main partners): entities names, and know-how involved
Who (else) was involved in the project ? (Inhabitants, local association, etc.)
More detail on the process and the role of the different stakeholders (How did it happen?)
OPTIONAL Considering the actual impacts, who are the primary beneficiaries of the project.
Cluster Governance Model Description
cluster5_network_governanceCollaborative_governanceIn comparison to conventional structural solutions, the smart, ecological urban rainwater management system implemented in Ober-Grafendorf has considerable cost advantages, both over the short and the long term, and it delivers a range of environmental co-benefits. Depending on the dimension and the accessibility of the site, the absolute investment costs for implementing the eco-street/DrainGarden concept can vary from case to case. The cost of the substrate for one cubic metre is about 100€. Depending on the choice of plants, the cultivation cost ranges from two €/sqm for seeding to several thousand €/sqm for planting large woody perennial plants. While a budget of 65.000€ was available for the process management and support services within the EU co-funded C3-Alps project ‘Capitalising Climate Change Knowledge for Adaptation in the Alpine Space’, the municipalities and other stakeholders did not receive any funding or remuneration for participating in the regional pilot process and for implementing concrete measures. However, the process managers provided consulting and advise on available financial incentives and financing opportunities within existing funding programs of the provincial state and the federal government. In general, the adaptation activities defined and implemented by the municipalities often were soft and low-cost measures, rather than technological solutions requiring substantial investments.
Financing
Global Estimated cost of the project -
Cluster cluster1_public_financing
FM CLUSTER 1: Public financing
Description of the financing mechanism In comparison to conventional structural solutions, the smart, ecological urban rainwater management system implemented in Ober-Grafendorf has considerable cost advantages, both over the short and the long term, and it delivers a range of environmental co-benefits. Depending on the dimension and the accessibility of the site, the absolute investment costs for implementing the eco-street/DrainGarden concept can vary from case to case. The cost of the substrate for one cubic metre is about 100€. Depending on the choice of plants, the cultivation cost ranges from two €/sqm for seeding to several thousand €/sqm for planting large woody perennial plants. While a budget of 65.000€ was available for the process management and support services within the EU co-funded C3-Alps project ‘Capitalising Climate Change Knowledge for Adaptation in the Alpine Space’, the municipalities and other stakeholders did not receive any funding or remuneration for participating in the regional pilot process and for implementing concrete measures. However, the process managers provided consulting and advise on available financial incentives and financing opportunities within existing funding programs of the provincial state and the federal government. In general, the adaptation activities defined and implemented by the municipalities often were soft and low-cost measures, rather than technological solutions requiring substantial investments.
Business Model
Class Type Description
Confirming the innovation potential of the project, the measure has won the Austrian Energy Globe Award in the category “water” and a Climate Star award in 2016. The adaptation solution has since then been tailored to different context situations and has been applied also in other municipalities and large cities, including Vienna.
Temporal Factor
Expected time for the NBS to be fully effective after its implementation
Expected life time of the intervention
Already feedbacks on the project? In case, the project has already been adapted to new requisites, please explain the modifications brought
Success and limiting factors
Process Enablers
Class Subclass Type Description
Knowledge_driversGeneration of evidence Collaboration Awareness • Lesson learnt through implemented projects; • Co-creation; • Climate Change Main success factors that facilitated the implementation of the measure include the following: • The municipality of Ober-Grafendorf has long-standing experiences in climate mitigation, energy efficiency and sustainable development activities. It has for years been an active member of respective networks and programmes, such as the Climate Alliance, the EU5 Programme, the Climate and Energy Model Region “Mostviertel Mitte”, Fair Trade Municipalities, and, most recently, the Covenant of Mayors. Past experiences with local integration of environmental policy themes and active participation in municipality networks have contributed to paving the way for the entry of climate adaptation into the municipal agenda. • As an ecosystem-based adaptation measure that responds to several climate change impacts at the same time and delivers multiple environmental co-benefits, the measure can be considered a good practice example of sustainable adaptation. • The measure performs very well as regards cost-effectiveness, and it has comparative cost advantages against conventional solutions. It thus saves public money and disburdens the municipal household. Moreover, the regional adaptation process conducted within the “seed-funding” C3-Alps project proved successful in raising awareness about climate change and adaptation needs, in communicating climate adaptation as well as in transferring adaptation knowledge and building adaptive capacities. It was thus the crucial trigger in putting climate adaptation on the agendas of the participating municipalities. As regards the entire regional adaptation process as such, the novelty of climate adaptation as a local policy theme in combination with the dominance and previously achieved depth of integration of climate mitigation and renewable energy issues at the local level proved to be the most limiting factor. Discriminating adaptation from mitigation was thus difficult to many municipal stakeholders. As a consequence, a part of the developed adaptation measures had a strong bias towards climate mitigation and were lacking the clear adaptation relevance. Another difficulty was that at the time of implementing the process a regional adaptation strategy at provincial level was still missing. The adaptation options set out in the National Action Plan on Adaptation to Climate Change proved to be ill-suited for the local level, i.e. they were perceived as too abstract, strategic and distant. Thus, considerable efforts had to be invested in “translating” and “down-scaling” adaptation options from the national to the local level.
Governance_driversProcess efficiencies Co-creation and participation • Collaboration • Coordination role; • Co-production
Economy_driversDe-risking Government support • Sharing risks; • Provisioning of incentives to attract private investment
Process Inhibitors
Class Subclass Type Description
Knowledge_driversUncertainty • Operational unknown
Governance_drivers-
Economy_drivers Budget constraints
What makes this project a pioneer?
Field
Criteria
Brief description of the innovativeness
Has the project received a prize, an award?
Has the project received a media coverage? (in reviews, in press, etc.)
IM Keywords
References