Book Description

WITHDRAWN - SUPERSEDED BY DG 365 2016 (not available yet)

Soakaways have been the traditional way to dispose of stormwater from buildings and paved areas remote from a public sewer or watercourse. In recent years, soakaways have been used within urban, fully-sewered areas to limit the impact on discharge of new upstream building works and to avoid costs of sewer up-grading outside a development. Soakaways are seen increasingly as a more widely applicable option alongside other means of stormwater control and disposal. Soakaways must store the immediate stormwater run-off and allow for its efficient infiltration into the adjacent soil. They must discharge their stored water sufficiently quickly to provide the necessary capacity to receive run-off from a subsequent storm. The time taken for discharge depends upon the soakaway shape and size, and the surrounding soil’s infiltration characteristics. They can be constructed in many different forms and from a range of materials. This Digest describes design and construction procedures, explains how to calculate rainfall design values and soil infiltration rates, and gives design examples. 8 pages.

Reprinted with minor corrections 2003. Reprinted with minor typographical revisions March 2007.

Soakaway design software was published in March 2007 as BRESOAK.