Drainage & Water Control

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Introduction to Drainage

What are Water Control Works?

  • Water Control Works, is defined according to The Water Rights Act as any dyke, dam, surface or subsurface drain, drainage, improved natural waterway, canal, tunnel, bridge, culvert borehole or contrivance for carrying or conducting water that:
    • Temporarily or permanently alters or may alter the flow or level or water, including but not limited to water in a water body, by any means, including drainage, or
    • Changes or may change the location or direction to  flow of water, including but not limited to water in a water body, by any means, including drainage.

What is drainage?

  • Large or small, a drain is a type of Water Control Works defined by The Water Rights Act.
  • Drainage is the natural or constructed method of moving excessive surface and subsurface water from one area to another. The usual goal is to improve agricultural production, but this is also done for the purpose of development or keeping road and rail beds from having water sitting against them and reducing their integrity.
  • The purpose of agricultural land drainage is to remove any water that is in excess of what the crops need during the growing season which, if not removed within a certain time period, could either destroy crops or substantially reduce yields.
  • Agricultural drainage systems are not flood control systems; they do provide some degree of enhanced drainage of spring flood water and may accelerate the time by which seeding is possible, but their flood control benefits are incidental to their primary purpose of removing excess water from agricultural lands during the growing season.
  • When drainage is undertaken without authorization, most times it will cause cumulative negative impacts to another person’s property either upstream or downstream. With authorization simply means that others’ interests are taken into consideration for the good of the landscape and the watershed.

Benefits and impacts of water control works and drainage:

  • Water control works have many beneficial purposes. Dikes, dams and diversion channels can provide individual or community flood protection. Retention projects can provide a multitude of benefits such as flood reduction, water supply, water quality improvement, wildlife habitat, and recreation opportunities.  Improving drainage of agricultural lands has economic benefits to landowners.  Agricultural drainage allows more acres to be farmed, earlier seeding, increased yields, and less risk of losses due to access moisture and flooding.
  • However, water control works and drainage projects can have negative impacts on water quality, quantity, and wildlife habitat on a local or cumulative, watershed scale. Steps need to be taken to be responsible and to reduce downstream impacts.

Sustainable drainage management