Further to Tomkins' posting
there are a number of sources of guidance relevant to public safety considerations. These include:
(a) “Watercourses in the Community” (SEPA, 2000).
http://search.sepa.org.u...the+community&n=sepa(b) “Ponds, Pools and Lochans” (SEPA, 2000)
www.sepa.org.uk/water/wa...tice_guidance.aspx#Ponds(c) “Technical design details – embankments” (Environment Agency, 2007)
(d) “C522 – “Sustainable Urban Drainage Systems – Design Manual for England and Wales” (CIRIA, 2000); superseded by C697
(e) “C697 – The SUDS Manual” (CIRIA, 2007)
(f) “C689 - Culvert design and operation guide” (CIRIA, 2010)
(g) Various case studies on the Visitor Safety in the Countryside Group website including an open watercourse in Halifax
www.vscg.co.uk/documents/uploads/Halifax.doc►
(h) “Safety at Inland Water Sites” (RoSPA, 1999)
(j) BS5499:2002 Part 11 “Water Safety Signs”
(k) “National Water Safety Signs” (RoSPA, initially published in 1980)
www.rospa.com/leisuresaf...al-watersafety-signs.pdfSEPA are critical of culverts, artificially straightened and mechanically excavated channels for various reasons including fast flowing water, flooding problems, adverse impact on the visual environment and biodiversity and safety issues in relation to steep slopes (or vertical drops), pipework and security grills.
SEPA support the restoration of watercourses where this is practical, and devote a Chapter in “Watercourses in the Community” to this topic. SEPA note various safety benefits associated with open watercourses when compared to artificial structures:
They are less prone to flooding, especially flash flooding
There are no grills or pipes into which children can be attracted, and become trapped
The banks tend to be more gently sloping - making it easier for someone who has fallen in to clamber out.
The restoration of watercourses offers significant ecological benefits, e.g. as a result of the creation of riffles, meanders, pools and planting.
SEPA policy (and that of the Environment Agency) is the avoidance of new culverts except where these are necessary.
In terms of slopes for river restoration projects, references (a), (b), and (d) recommend “one in four or less”, reference (c) notes “typically one in 2.5 to 3”, and reference (e) recommends a maximum of “one in three”.
It is understood that the more recent CIRIA guidance reflects advances in technology e.g. the ability of ride-on mowers to traverse somewhat steeper slopes.
Whatever the slope, any risks can be further reduced by careful consideration of the location of footpaths, e.g. to leave a strip between path and the water’s edge, and by planting of bankside and/or aquatic vegetation. Where such vegetation has sharp foliage it acts as a natural deterrent, as does mud at the water’s edge.
Where a hazard has not been eliminated during design phase or reduced to an acceptable level of risk, there is a need to provide the public with information about.
risks that might not be obvious e.g. where there are underwater hazards that are not visible
hazards which pose significant risk e.g. sheer drops, particularly if associated with new infrastructure