Hydrological zoning (or simply zoning) is an approach to divide land into different zones based on their hydrological properties. Typically, each type of zone has different land use and development regulations linked to it. This land and water management method aims to protect local water sources from risks of over-abstraction, land salinization, groundwater pollution and waterlogging by managing land use activities based on the assigned hydrological zones. For example, zones with a high groundwater table, large amounts of surface water (e.g. rivers) or high erosion susceptibility will usually have more land-use restrictions in place. Such restrictions may limit irrigation to avoid nutrient loading and sediment runoff into watersheds, but can also limit other activities such as industrial discharge and water abstraction from surface or groundwater sources. Zoning also ensures that irrigation, urban development or other land-use activities take place in the ideal land areas in relation to local hydrology, as well as where environmental impacts can be mitigated.