Page 141 - Newham SuDS DESIGN & EVALUATION GUIDE

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Detailed Design The safety considerations in basin, wetland 3. Permanent pond depth need not exceed 4. All hard engineered structures should be 7. Where unsupervised toddlers may be Detailed Design
expected a 600-700mm picket fence
set back 1m from permanent water edge,
600mm as this is a common depth of
and pond design should be considered
which will prevent drowning in the event
natural ponds and where most biological
should be considered as this stops most
carefully.
toddlers and allows adults to easily step
of concussion.
activity occurs. However, a depth 600mm
1. The profile of the structure should allow
without regular maintenance means that
over the fence for rescue.
5. Protective fencing will not keep children
easy and safe access for people and
vegetation will cover the pond in time.
out of ponds and merely acknowledges a
maintenance machinery. Slopes should
8. There must be an acceptance by the
Most wetland edge plants cannot colonise
community that open water is part of a
not exceed 1 in 3 or 1 in 4 and in larger
dangerous condition. Well designed
beyond 1.2m depth of permanent water.
basins access ramps with a more gentle
sensitively communicate health and safety
accessible for rescue if this is required.
slope should be considered. The idea of a
the pond, with surrounding shallower
series of slopes and level benches is now Therefore, an deeper area in the centre of ponds should be easy to exit and landscape character. It is useful to
messages identifying the presence of
benches can be considered if open water 6. Pond depths and profiles should not be
accepted as an appropriate detailing for permanent and temporary water using
is desired. Effective storage of 600mm designed for ease of open water
SuDS basins and ponds. well designed informative signage.
over permanent water depth of 1.2m swimming. This can be achieved by
2. The overall depth of temporary storage provides a total potential stored depth of varying the profile of the pond 9. The use of ‘danger – deep water’ signs
should not normally exceed 600mm as 1.8m and the design must take this into throughout. and lifebuoys should be avoided, as they
this depth is critical for a feeling of safety account. imply that risks have not been sufficiently
in water. The bottom of the temporary catered for by design.
storage dry basin should slope gently so
that most of the time the base is firm and This project failed to adequately consider
dry. Shallow micropools and wetland health and safety when designing attenuation
features into a residential pocket park. There is
habitat should be integrated carefully into
now no public access allowed. There should be
the basin as they will not be visible when no need for such measures if properly
135 the basin is full of water. designed. 136

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