Gullyhawk tackles blockage problem in one fell swoop

Given recent patterns of heavy rainfall and the resultant flooding, there has been focused attention on blocked road gullies. A new remote system that monitors silt levels - saving time, money and traffic congestion - may well be the solution.

AS THE UK continues to experience unexpectedly high levels of rainfall over short periods of time, innovative methods are being sought across many industries to help alleviate flooding.

One industry that has felt the effects of high rainfall levels for many years is the highways industry. Here excessive surface water can prove hazardous to pedestrians and motorists. As rainwater collects on the carriageway following a heavy downpour, it is vital the water is able to drain easily away from the road surface into roadside gullies connected to the drainage network.

Road gullies are designed to trap any small debris, such as mud and small stones from the road surface, while allowing water to flow freely out of the pot from a high-level exit pipe. Over a period of time, this debris builds up and, if not removed, will block the outlet pipe.

Abortive work

A blocked outlet pipe means water cannot flow away, which can result in both standing water on the carriageway and the passing of debris, intended for the gully pot, into the pipe network.

To overcome this problem, the highways industry uses road-gully-cleaning vehicles to empty the pots as part of a cyclic maintenance programme. Not knowing when and where to target gully emptying means crews spend numerous shifts on abortive work – carrying out a cyclic maintenance programme that is not only costly and potentially dangerous, but is also not required.

The UK’s wastewater industry was faced with a similar problem because parts of the sewerage network are prone to overflowing, causing environmental pollution damage.

To address this problem, IETG developed the Hawkeye system, which remotely monitors sewerage levels across parts of the network. The system sends alarms to the network operator when certain preprogrammed levels are reached.

Hawkeye is being run by a number of the UK’s water companies.

Following consultations with the highways industry, IETG has since adapted the system and developed Gullyhawk as a means of tackling the issue of overflowing and blocked road gullies.

Stuart Learmonth, managing director of IETG, says: “We developed the Hawkeye remote-monitoring system for the water industry, and our customers have been reaping the benefits ever since. We recognised the challenge that the highways industry was facing, and it made sense to adapt this proven technology and develop Gullyhawk to solve the drainage problems associated with highways gullies.”

A-one Integrated Highway Services is the managing agent contractor for the Highways Agency’s Area 14 network of motorways and trunk roads in the North-east. It identified the need within the industry to develop an alternative method of managing the gullies. In consultation with A-one, Highways Agency, and Jigsaw Consulting, IETG developed the Gullyhawk system for monitoring silt levels in highway gullies. It trialled it across two sections of the Area 14 road network.

The battery-powered Gullyhawk units each include a monitoring probe and light sensor as well as data capture and radio transmission equipment. They are installed into gullies.

The light sensor is used to measure the level of silt in the gully pot. The units transmit this information to a data hub located on the monitoring network. In turn, the hub transmits the packets of data to A-one’s IT system using GPRS technology. The data is then stored and linked automatically to A-one’s GIS system, displaying the results in a traffic-light-type display onto a mapping background. This enables maintenance crews to quickly determine the state of the gullies in real time.

Automatic functions

The whole system, once installed, needs no human input, working entirely on automatic functions to gather, process, and display the data.

Using the one-size-fits-all design, the units can be fitted into any gully type, then targeted at areas of the network that either have a history of flooding or have restricted access.

By ascertaining the frequency for emptying gullies, A-one is now able to only empty gullies that are nearly full. This reduces the number of gullies visited, improving traffic management time. This saves time, money, inconvenience, congestion, and the environment through less activity and reduction of fluid disposal.

As the deployment of Gullyhawk progresses within the industry, IETG will continue to work with the industry partners on its further development. It is already looking at including monitoring rainfall data so that the units can provide contractors with essential information on heavy rainfall as well as silt levels.

By enabling silt levels to be measured and monitored, Gullyhawk provides an alternative method of managing the gullies. It also makes it possible to target interventions on the gully drainage network, and also enables the industry to move from the traditional approach of cyclic maintenance to a more intelligence-led way of working.

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