British Waterways Droughtbuster

Due to climatic, environmental and industrial changes in the past few years, parts of the canal network, in particular the Grand Union, suffer from low water conditions during the peak summer months. This results in, at the very least, boats grounding and in the worst cases whole sections of the canal network being closed off.
As the greater proportion of British Waterways' profit is gained from the leisure market rather than commercial traffic, and this market is very seasonal - mostly during the dry summer months - this trend of low water conditions was giving cause for concern.
The 'Droughtbuster' system was conceived to alleviate this seasonal problem.

 The grand union canal
Every time a boat passes through a lock, a considerable amount of water is used. This is replenished at the high points of the system from rivers or reservoirs - or even from pumped boreholes. The Grand Union Canal is fed from a reservoir, and during periods of drought British Waterways was finding it increasingly difficult to obtain the volumes of water necessary to keep the system operational. It was decided to use a fundamental constituent of the lock system, i.e. the weir channels, to solve the problem. Each lock has a weir adjacent to it to allow excess water ( in cases where an upstream lock has been used), to bypass the lock rather than spill over the gates. The proposal was to suspend a pump in the weir chamber and lift the excess water back to the upper level, thus recirculating the water, using a pump at each of the lock sites, ultimately to the head of this particular stretch.

Scope
 
To provide, install and maintain pumping capability of minimum 200 litres per second at approx. 3m static head at 8 single lock locations (‘A’ sites) and 3 multi-lock locations (‘B’ sites).
 
To provide temporary generators and bulk storage tanks fully bunded at 5 sites initially, and provide refuelling facilities for a period of approximately 26 weeks.
To provide level control systems at each site to allow British Waterways to ‘fine tune’ the system, thus allowing a balanced flow to be transported up through the system of locks.

Rental Contract

British Waterways Droughtbuster programme

Technical aspects

 
Power supplies to the locks were either limited, or in some cases non- existent, resulting in the need for temporary generators and fuel supplies.
 
Support steelwork was needed over the weir chamber on single lock sites to suspend the pump and provide support and access to valves and pipework.
 
‘ A ‘ frame gantries were provided over the semi permanent sumps at multi-lock sites.
 
Access on all sites was difficult for the initial installation and subsequent refuelling of the generators.
 
The problems of working next to water had to be taken into consideration.
 
At all times, the canal system was to be kept operational.
 Equipment supplied
8 type A locations consisting of :

1 x CS 3201 MT pump c/w 250mm pipework and valves, suspended/ supported from a purpose designed bridge, control equipment, including multi-head level control probes and associated cabling, housed in a single mild steel kiosk.

3 type B locations consisting of :

1 x BS2250 MT pump and 2 x CS 3300 MT pumps c/w equipment as above, excluding the level controls.

The equipment used was installed, commissioned and maintained for a minimum rental period of 26 weeks, followed by the option to buy.