1 Scope
This document provides guidance on the collation of the measurements required for
the management of sedimentation at river structures. These include structures used
by water supply utilities, other major water abstractors, HEP producers, bridges,
and for flow measurement by environmental protection agencies. It is intended to be
used at sites where the sediment ranges in particle size from fine colloidal material
to coarse gravel, that is, sediment normally transported by flood flows. It is not
intended for use at sites where major channel bed regrading is to be undertaken requiring
the major excavation of solid bed material.
The document is also intended for use when a redundant structure is being removed,
or when modifications to a structure are being made to facilitate fish migration or
for river restoration. This is to ensure that the impacts of these changes are adequately
monitored and recorded.
The document covers the provision of routine measurements, and the checks and requirements
that are to be made by the operator so that specific basic information is collated
and made readily available. This information is used to inform decision-making by
environment management agencies that authorize flushing, sediment clearance or sedimentation
removal. This is to ensure minimal environmental impacts, and to support compliance
with existing environmental legislation.