Doe Park ReservoirDoe Park Reservoir
is impounded behind a Victorian “Pennine type” embankment dam; the
total volume of water stored is approximately 800000m3.
A statutory inspection recommended that improvements be made to the
wave wall and overflow structures to enable the reservoir to safely
pass the Probable Maximum Flood (PMF). Mott MacDonald Bentley Ltd
(MMB) was commissioned by Yorkshire Water Services to carry out
feasibility, detailed design and construction of these works. The
scheme was recently commended in the ICE Yorkshire & Humberside
Awards 2008.
The main elements of the scheme were as follows:
- Design & reconstruction of dam crest to ensure the flood
rise from the PMF was fully contained.
- Design and construction of a 17m single-span bridge over the
spillway channel (for HA loading).
- Design and construction of a new concrete spillway channel
capable of passing the design flood of 120m3/s.
- Improvements to the existing valve shaft and access bridge such
that the shaft does not act as an overflow during the PMF.
Traditionally a scheme of this magnitude would take up to 12 months
to construct but the use of innovative techniques and Egan
principles reduced the construction time to just over six months:
- Use of masonry effect “formliner” on exposed external concrete
faces on the wave wall and spillway in place of traditional
masonry. As well as being more sustainable (avoiding the need to
quarry stone), the option saved approximately £70 000.
- Use of prefabricated reinforcement during construction of the
spillway – an option that saved considerable construction time and
was safer as it minimised the amount of steel fixing needed on
site.
- Use of precast concrete wave wall units saved approximately 12
weeks of construction time compared with the traditional solution
of in situ concrete and shuttering. This helped maintain access to
a property on the other side of the dam.
- Re-cycled sludge (treated and supplied by Yorkshire Water) was
used in place of traditional topsoil, saving approximately £14
000.
- Collaborative planning and lean construction techniques were
used to ensure the scheme was delivered from receipt of brief to
substantial completion in just 12 months.
The public interface was sensitively managed during the
construction phase and several improvements were made to the
sailing club facilities once the scheme was complete such as a new
slipway and recreational area. Site staff received praise from
local residents and the sailing club for their helpful and
sympathetic practices when working on the project.
Doe Park Reservoir intake tower
