Controlled drainage for integrated water management

Controlled drainage is an essential component of Integrated Water Resource Management (IWRM) and Water Demand Management (WDM). Controlled drainage can play an important role to save water and nutrients and to improve and optimise downstream water availability and quality. Examples of controlled drainage practices in the Netherlands, USA, Egypt and brief references to work in other countries are given. Shifts in priorities of different aspects of water management take place. These shifts in paradigms to ¿do not drain unless absolutely necessary¿, controlled drainage, and ¿give room to flood waters¿ (controlled flooding) are described. In the Netherlands, the new water management tool Waternood emphasises the relation between land functions and water management and aims at managing conflicting objectives. The impact of agricultural water management on nature and the use of Best Management Principles (BMP) to control downstream impacts are described. In the USA, sub-irrigation is also a component of BMP and controlled drainage. The options, advantages and constraints of controlled drainage are given, while on-going activities in the field are presented