Deltas are attractive to live, economically develop and regenerate. The development of river floodplains is especially interesting in areas when available land is scarce. In this Delta Fact we elaborate on a concept dealing with floodplain development: Room for the River. The core of the room for the river concept is giving more space to the river in order to increase the velocity of the flow or to reduce the water level of excess flows and time of exposition to large floods. It can be described as a ‘’simultaneous move from vertical flood defences [reinforcing embankment’s] to horizontal expansion (widening) of rivers, and from vertical, top-down management to more egalitarian forms of multi-actor network governance’’ (Warner et al, 2013). It is a resilient approach accepting that flooding may occur now and again, but seeks to exploit the advantages of flooding and mitigate the disadvantages. It is a broad concept, applicable and adjustable to many different circumstances (Warner et al, 2013).
The Room for the River concept is related to river restoration or rehabilitation, sustainable river management, river flood management and river widening (Warner et al, 2013). Variants of the concept are executed worldwide.
Constraining the river has its price (notably flood risk and loss of natural carrying capacity) but so does making space. More space for the river easily means less space or less opportunity for other functions that are also societal appreciated (e.g. housings, business areas and other) (Warner et al, 2013). The costs of room for the river measures differ per country, but are relatively easy to calculate. On the contrary, the benefits of room for the river are more difficult to value. Flood safety, nature and recreation may positively benefit from room for the river measurements, while agriculture and shipping may negatively benefit. Effects on recreation and nature are difficult to estimate and even more difficult to monetize.
In the Netherlands a cost effectiveness analysis and a cost benefit analysis on the optimal safety strategy were performed. Cost effectiveness of the reduction of the water level was expressed as mm/million euro or m2/m euro. This allows for selection of the most cost effective measure for each river branch or river stretch. The general conclusion was that relocating embankments, bypasses, lowering groins and lowering floodplains yielded the largest design water level effect per million euros invested. The most expensive measures were the removal of hydraulic obstacles and lowering floodplains (Silva et al, 2001). It was also concluded that spending more than 2 billion euro for improvement of flood protection in the Dutch rivers was economically viable (CPB, 2005; Eijgenraam, 2005).
The effects of room for the river measures are manifold, affecting agriculture, nature, housing, cultural heritage and shipping. The benefits of these effects depend on the type of measure. For example, there are different possibilities to lower floodplains: by means of nature development, replacement of dry and humid nature for wet nature or with vegetation management. All these variants will yield different benefits (Klijn et al, 2012). Besides that, the benefits of the measures highly depend on the location.
Evaluation of the Dutch Room for the River program
The room for the river program is considered as a successful project. In the Netherlands, it is the first major infrastructure project to be realised on time and within budget (Rijke et al, 2013). The flood protection objective will be reached for 61 per cent in 2015. This will grow during the years after (Andersson Ellfers Felix, 2013).
The contextual factors that made the program a success are (Zevenbergen et al, 2012):
European Centre for River Restoration
Since 1995 the European Centre for River Restoration, based on a framework of national networks,enhances and promotes river restoration and sustainable river management throughout Europe and disseminates information on river restoration experiences and approaches and to foster the establishment of national river restoration networks in as many European countries as possible. Best practices, lessons learned and literature references can be found at: www.ecrr.org. Also www.restorerivers.eu supplies information on best practices of river restoration.
The Dutch room for the river program is almost completed. Although most knowledge gaps have been solved during the program, there are still some remaining questions: the effect of making room for rivers on flood risk (probability x consequence) has never been properly quantified (Klijn et al, 2012), the same counts for a cost benefit analysis including benefits for nature, culture historic value and more.
Other knowledge gaps are the opportunities to link spatial planning, policy or tasks to the room for the river program and the ability to adapt to potential larger river flows in the future (Rijke et al, 2013). Furthermore, the effect of the approach on water supply is a knowledge gap. International there are many knowledge gaps such as the transferability of the concept to (developing) countries. Although, the factors that made the program a success have been identified, the context will be different in another country and approaches have to be adapted.
- Andersson Elffers Felix (2013). ¾ Evaluatie Ruimte voor de Rivier, Eindrapport. GR103/rapport, Utrecht.
- Buuren van, A., Edelenbos, J., Warner, J., (2013). Chapter 14: Space for the river: governance challenges and lessons. In: Warner, J.F., Buuren van, A., Edelenbos, J. (2012) Making space for the river, governance experiences with multifunctional river flood management in the US and Europe. IWA Publishing
- Climate Adaptation (2013). Europe: Casualties in the past.
- CPB (2005). Notitie: Kosteneffectiviteitsanalyse van het maatregelenpakket in de PKB Ruimte voor de Rivier deel 3.
- Ebregt, J., Eijgenraam, C.J.J., Stolwijk, H.J.J (2005). Kosteneffectiviteit van maatregelen en pakketten: Kosten-Batenanalyse Ruimte voor de Rivier, deel 2. CPB, document 83.
- Eijgenraam, C.J.J. (2005). Kosten-batenanalyse Ruimte voor de Rivier deel 1, veiligheid tegen overstromen. CPB, document 82.
- International Commission for the protection of the river Danube (ICPDR). (2009). Sub-basin level flood action plan Tisza river basin.
- Kleinhans, M.G., Klijn, F., Cohen, K.M., Middelkoop, H. (2013). Wat wil de rivier zelf eigenlijk? Deltares report number 1207829.
- Klijn, F., Bruin de, D., Hoog de, M.C., Jansen, S., Sijmons, D.F. (2013). Design quality of Room-for-the-River measures in the Netherlands: role and assessment of the quality team (Q-team). International Journal of River Basin Management.
- Klijn, F., Kok, M., Moel, H (ed.) (2012) Towards climate-change proof flood risk management, exploration of innovative measures for the Netherlands’ adaptation policy inspired by experiences from abroad, interim report. Knowledge for Climate Report nr. KfC 57/2012.
- Rijke, J., Herk van, S., Zevenbergen, C., Ashley R. (2012). Room for the river: delivering integrated river basin management in the Netherlands. International Journal of River Basin Management 10:4, 369-382.
- Rijke, J., Herk van, S., Zevenbergen, C., Ashley, R. (2013). Towards integrated river basin management: Governance lessons from Room for the River. In: Klijn & Schweckendiek (eds), Comprehensive Flood Risk Management. Taylor & Francis Group, London.
- Room for the River (2013a) Brochure [online] http://issuu.com/ruimtevoorderivier/docs/rvdr_corp_brochure_eng__def._
- Room for the River (2013b). Making room for Governance, Factsheet.
- Silva, W., Klijn, F., Dijkman, J. (2001). Room for the Rhine branches in the Netherlands, what the research has taught us. WL Delft Hydraulics, Directorate-General for Public Works and Water Management, IRMA.
- Spatial Planning Key Decision Room for the River (2006). Approved decision.
- Verkerk, J., Buuren van, A. (2013). Chapter 2: Space for the river: a condensed state of the art. In: Warner, J.F., Buuren van, A., Edelenbos, J. (2012) Making space for the river, governance experiences with multifunctional river flood management in the US and Europe. IWA Publishing
- Warner, J., Edelenbos, J., Buuren van, A., (2013). Chapter 1: Making space for the river: governance challenges. In: Warner, J.F., Buuren van, A., Edelenbos, J. (2012) Making space for the river, governance experiences with multifunctional river flood management in the US and Europe. IWA Publishing
- Zevenbergen, C., Rijke, J., Herk van, S., Ludy, J., Ashley, R (2013). Room for the river: International relevance. Watergovernance 2, pp 24-31.
This Delta Fact is prepared by Deltares on behalf of the Ministry of Infrastructure and Environment, RWS Corporate Innovation Program and the CLIMATE KIC Working with Nature pathfinder project.
Auteurs: Femke Schasfoort, Stephanie Janssen, Maaike Bos, Felix Francés
This Deltafact is partly based on an interview with Marco Hoogvliet (31 July 2013) and the results of a ‘Room for the River’ CANVAS Business Model workshop (20 June 2013)
Island in the river Waal
A bottleneck within the room for the river program was the part of the river Waal flowing through the city of Nijmegen. Enclosed by an urban area, the river had limited space to discharge all the incoming water. In Nijmegen two large room for the river measures were proposed, the construction of a bypass and setting back of the ‘Lentse Waaldike’. Since, the area is highly urbanized, finding public support for these measures is very important. The agreement has been reached in participation with many stakeholders such as local residents, NGO’s and the local government. The process included an extensive Environmental Impact Assessment and planning study followed by a design and technical plan. Currently, there is enough public support for the measures resulting in a faster implementation process.
The plan comprises a relocation of the dike 350 meter inland. This creates space to build a bypass, which will give more discharge capacity during high water levels. This means a large spatial intervention for the city of Nijmegen, around 50 houses have to make room for the water and there will be build a large city park in between the historical centre and the city district Waalsprong.
The plan needed to fulfil a water level reduction of 27 centimetres and an enhancement of the spatial quality of Nijmegen. Both of the goals are reached, even a water level reduction of 35 centimetres has been achieved (Ruimte voor de Waal, 2013).
Environmental restoration and educational use of Almenara Marsh
Almenara Marsh is located besides the coast, originally occupying fields of several municipalities in the province of Castellón (Spain). The marsh area was reduced significantly in the past, mainly by agricultural land development. Nowadays only one water body at Almenara municipality is remaining.
The environmental restoration of this marsh was proposed by the Júcar Basin Water Authority to solve flood problems in a residential coastal urban area. The area is located between the marsh and the sea. Works finished in 2013 with a total cost of 900,000 €.
The main objectives for this project were: (1) use the wetland as a sacrifice area during flood periods, releasing water to the sea after the storms; (2) wetland restoration and landscape improvement; (3) control the water level and the connection with the sea in order to improve the biodiversity and environmental aspects of the wetland; and (4) educational/social use of the restored wetland.
For flood protection a drainage canal was constructed parallel to the coastline between the wetland and the residential area. The historical agricultural drainage system has been maintained. To increase the water control capacity a pumping station has been constructed.
This project is a clear “Working with Nature” project since it uses natural processes to restore a degraded wetland and use it in periods of flooding as a sacrifice area. In addition, the project has produced environmental and social gains: the wetland water balance is controlled and the ecosystem functions have been improved. The marsh is turned into an improved natural habitat for many species, including endangered ones.
The knowledge and diagnostic methods presented in this publication are based on the latest insights in the professional field(s) concerned. However, if applied, any results derived therefrom must be critically reviewed. The author(s) and STOWA cannot be held liable for any damage caused by application of the ideas presented in this publication.