Drain Surveys
The standard methodology usually used for detailed survey of watercourses such as drainage ditches and other linear waterbodies was devised by Alcock and Palmer (1985). A grapnel is used to retrieve submerged and floating aquatic vegetation accessible from the bank along a sample length of the watercourse and the abundance of each species is recorded.
Data are also collected concerning the health of the aquatic plants, water levels in the ditches and the potential for the recorded conditions to sustain the present nature conservation interest. Physical characteristics and the health of plants are recorded, a sketch map produced and record photographs taken.