Good practices in land use planning is the most cost effective and environmentally sound way of reducing risk of damage from flooding and other hazards. There is a continued and increasing pressure for urban development along rivers.
River properties are often attractive, gaining high prices and also have relatively low development costs. This is however often in conflict with both environmental and flood safety concerns.
NVE addresses this issue using several different approaches. The Norwegian Planning and Building Act states that development is not allowed, unless safety is at an “acceptable level”, with local municipalities responsible for ensuring that this is the case. NVE offers guidance to local municipalities in the form of flood inundation maps, maps showing areas at risk of quick clay landslides and gives expert advice to municipal land use plans.
NVE has also developed a national guideline defining acceptable safety levels with respect to floods and other hazards related to rivers. The safety levels are differentiated related to hazard type and type of asset. A stepwise procedure for assessing the hazards has been designed to fit with the planning process and levels typical for a local municipality. The following procedure is recommended:
- Municipal plan: potential hazard should be identified
- Zoning plan: the actual hazard should be described and risk quantified
- Building case: a satisfactory level of safety must be documented
This procedure ensures that areas with a potential hazard are identified at an early stage in the planning process giving municipalities more reliable and predictable land use plans.
NVE can raise an objection to a land use plan if due consideration to a flood or landslide hazard has not been taken into account. Areas that are especially exposed to danger of flooding, erosion, landslides and ice flows may be held on trust for further regulation as a danger zone.