C6.4 Land use planning controls and nature protection
An important topic for IWRM is the interface between water use and land use. Consequently, regulating land use is part of IWRM. The steady growth of urban agglomerations means that the water impacts of land use become of paramount importance. Urban growth leads to massively increased local discharges of waste effluent with serious impacts on surface and groundwater. In the same way forestry and agricultural activities have significant impacts on both the quality and quantity of surface run-off as well as groundwater formation and quality. Land use planning should be a significant component of implementing national plans for IWRM (see C2).
Land use planning can draw together the various impacts of population pressure or industrial land use on water to ensure sustainable water impacts. Land use planning is vital for safeguarding environmentally vulnerable areas, wetlands and also for riverine ecosystems. But pressure for land development is often intense, and there are frequent conflicts between the land requirements for housing, industry, roads etc. and the need for nature protection.
Examples of tools for controlling land use include:
- Zoning identifies areas where specific forms of land use are prohibited or where special rules apply. Examples relevant to IWRM are drinking water protection zones and zones where construction is not allowed because of flooding risks. Protection zones around wells and in recharge areas are useful for protecting groundwater and potable water drawn from wells. Protection zones along watercourses gives some protection against direct pollution, for instance from nutrients in fertilisers;
- Construction permits are sometimes required before houses or infrastructure can be built in protection zones or around urban areas to protect water quantity and quality. Land use planning can be used as an alternative to structural flood protection;
- Building regulations are likewise a means that can be employed to reduce vulnerability to floods;
- Specific soil protection and erosion control measures, such as ploughing parallel to the contour lines and planting trees, can be prescribed. Special limitations may apply in designated nature or wildlife areas;
- Waste disposal regulations, e.g. on locations of waste disposal sites, are important for the protection of groundwater.
Before controlling land use, a wide overview is needed on present land use, along with a vision on future land use. Additionally, adequate institutional capacity must be available for planning and for compliance monitoring and enforcement (B1.5, B2.3). This tool also has links to water resources assessment (C1).
- Structural flood protection has some serious drawbacks, such as the costs and the increased damage if the structures fail. Consequently, non-structural measures such as zoning deserve serious consideration.
- Integrating land use controls into IWRM requires effective co-operation and mutual understanding between land use planners and water managers. Co-ordination can be achieved, for example, through an apex body (B1.3).