Land development can affect the risk of flooding in a number of ways. First, development tends to replace soil and vegetation with impervious surfaces such as roof tops and asphalt. This means that rainfall that used to soak into the ground will flow directly into rivers and streams, increasing the amount of flow. Second, buildings, infilling with earth and other structures placed within flood plains can obstruct the passage of floodwaters. Finally the potential for flood damage is greatly increased when, through lack of awareness or disregard for the potential danger, unsuitable development takes place in areas that are already subject to flooding.
The best way to reduce risks to human safety and property damage from flooding is to identify locations that are prone to flooding (flood hazard areas) and avoid them when planning new buildings, roads and other vulnerable structures. Good planning practice indicates that land in areas that regularly flood should be limited to uses that are not greatly affected by flooding. These include parks, golf courses, recreation areas and parking lots, or uses such as agricultural or forestry or conservation.
Buildings that are already located in flood hazard areas can be “floodproofed”, which means adding temporary or permanent features to a building or its surroundings that reduce the potential for damage due to flowing or standing water.
The power to regulate the use of flood plain lands within municipal boundaries rests with the local municipal council under the New Brunswick Community Planning Act. Measures such as zoning by-laws, and building permits can be used to control and direct land use within the flood hazard areas.