Archived decisions

Contact: Kevin Fuller, ext 7958

1. Summary

1.1 This report outlines the current policy and procedures relating to weather emergencies and the impact of adverse weather on the highway network.

2. Background

2.1 The County Council has a clear obligation under the Highways Act 1980 to keep the network in a safe condition and allow the highway to be passed and re-passed without hindrance. These principles are long held in law and are built upon rights established since medieval times.

2.2 Inclement weather is a natural phenomenon and is dealt with routinely as part of the highway maintenance arrangements. More extreme conditions have been prevalent in recent years, with severe storms and excessive rainfall across the region. This has had a major impact on the highway infrastructure and daily travel within Hampshire.

2.3 Meteorological experts are predicting a change in weather patterns, pointing towards milder, wetter winters associated with global warming. The recent pattern of winters in Hampshire has been exceptionally mild but often includes a short, cold snap with associated ice and snow. Recent winters, however, have been dominated by prolonged flooding.

3. Winter Maintenance

3.1 The Highways Act 1980 places a duty upon highway authorities to clear snow from the network but there is no such duty to clear ice. The County Council, however, in recognition of the safety issues associated with ice formation on the network and, in line with all other highway authorities, has a policy to treat the network to prevent ice formation by de-icing and to eliminate ice where it has formed as quickly as practicable. The Government is likely to introduce legislative changes to require authorities to treat ice and snow on the network. In the light of this and the service delivery, the winter maintenance arrangements are going to be reviewed over the next year.

3.2 It is not possible to carry out treatment to prevent ice forming or clear snow on every part of the network all at once, and work is prioritised to deal with the most heavily-trafficked parts of the network first. In this respect the main road network, including major bus routes and large schools and hospitals, is treated as the first priority in advance of predicted ice, frost and snow. The first priority routes take about 85% of the volume of traffic and amount to some 2,500 kilometres or 26% of the network. The County Council has 42 first priority salting routes and employs gritting lorries, snow ploughs and blowers, etc to deal with those routes. The same vehicle fleet is used for the second priority routes and therefore these are treated only when the first priority routes have been satisfactorily cleared. The treatment of second priority routes is triggered after prolonged sub-zero temperatures with ice formation or following snow. Bus routes, schools, single access roads to villages and pedestrian precincts are included in second priority routes, which amount to about another 30% of the network. Priority 3 treatment follows the satisfactory treatment and clearance of the priority one and two routes. During times of heavy snowfall approximately 150 local farmers and other contractors are used to assist with the snow clearance operation.

4. Footway Treatment

4.1 Footways are not routinely treated in advance of predicted ice or snow. Salting (sometimes mixed with grit) takes place as required, concentrating on the most heavily used footways. Local contracted labour and Term Maintenance Contract (TMC) routine maintenance teams are used for this manual operation. The dry application of salt to footways is not always effective as it needs to be ground into the snow or ice to become effective. This is more difficult on a footway compared to a road. Trials of a footway applicator using a brine solution have been undertaken and look promising for the larger pedestrian precincts where there is sufficient space.

5. Practical Considerations

5.1 It is not always possible to prevent ice and snow formation or deal with it immediately, and a reasonable time is needed to treat the whole network. To complete a first priority route takes between 2.5 and 3 hours. There are some situations where salt has a limited de-icing effect. It is less effective below -5 degrees centigrade and in conditions such as freezing rain its de-icing capability is limited. The treatment is `just in time' to ensure that the salt has the maximum effectiveness and is timed, where possible, to take place in the evening and early morning when traffic flows are lightest.

6. Winter Maintenance Budget

6.1 The winter maintenance budget is not fixed because of the variable nature of the season and is based on a rolling four year average which is currently £1.65 million. A salting run which takes in all first priority salting routes county-wide costs approximately £22,000. In an average winter, treatment is carried out on 45 nights out of a 150, costing approximately £1.7 million, including both priority one and two routes.

6.2 Winter Maintenance Operation

(i) Weather Forecast: the marginal temperatures in this region make the business of forecasting for ice more difficult and complex than other regions with definite cold domains. To assist, the county has a network of mini-weather stations that continuously monitor the local conditions, road surface temperature etc. This data is used by the weather forecast service provider, together with the global computerised weather model, to predict the road surface temperatures and risk of ice or snow on the network. Based on this prediction a decision on salting is made by Hampshire Highways. The network has been thermally mapped, which gives a good indication of the relative temperatures between any part of the network. This gives the cold and warm spots on the roads and helps with the salting decisions required for the predicted temperatures.

(ii) Salt Application: Rock salt is used as the de-icing agent and county-wide some 12,000 tonnes are stored under cover in specially built barns. The County Council is using and developing `wetted salt' (or, to be more accurate, `dampened salt') which reacts quicker following application. Wetted salt tends to stick to the road surface and not blow away in strong winds. Its application can use up to 30% less salt than the traditional dry salting application and it is therefore more environmentally-friendly.

(iii) A new generation of gritting lorries is being provided for the salt application through the county-wide term maintenance contract with Raynesway Construction Southern Limited. The gritting vehicles have been equipped with dry, wet and brine application and have Global Positioning System satellite navigation fitted to give precise details of the routes treated, the timings and the salt quantities applied.

7. Flooding

7.1 In 2000/01 Hampshire suffered from the heaviest sustained rainfall for 230 years and consequently the worst flooding experienced in living memory. Severe flooding also occurred in 1995 and this year flooding is unfortunately approaching the levels of 2000/01.

7.2 Hampshire not only suffers from the twin risk of coastal flooding and fluvial flooding but, because of its unique geology, also experiences prolonged ground water flooding. The ground water flooding is caused by the chalk aquifers overfilling, usually towards the winter's end, and spilling out into dry rivers known as winterbournes; springs are also formed. Much of this water finds its way to the surfaced highway where highway drainage systems and ditches are quickly overwhelmed. These surface water drainage systems were never designed to accommodate such flows. The impact of prolonged flooding over a winter is not only devastating for residents, with property flooded, but also to the structure of the road. Severe damage was done to roads and bridges in 2000/01 and the cost to date of repairs and new drainage schemes exceeds £11 million. Of this £5.05 million was provided from the Government Office for the South East in recognition of the severity of the damage caused to the infrastructure.

7.3 Given the relative high cost of such repair work and apparent changes to climatic conditions in Hampshire, consideration may need to be given in the future to widening the scope of the winter maintenance budget, which has traditionally been used to fund pre-salting and snow clearance operations, to include emergency repairs which result from flooding.

8. Flood Steering Group

8.1 Following the flooding in 2000/01, the County Council convened a steering group of the relevant authorities with the intention of working together to improve the way that flooding events are managed, to help mitigate their impact. The group is chaired by the Environment Agency. There are some 230 parishes in Hampshire and the parish and town councils were identified as key players in dealing with flooding and therefore were also represented on the group. Good progress has been made in a number of key areas through joint working and are listed below:

(i) coordination of physical works as joint projects;

(ii) specific reports and investigations carried out by the Environment Agency at each of the 106 sites (713 homes) that suffered from property flooding. The identification of realistic measures to mitigate the impact of flooding and agreement of the relevant authorities involved to follow up;

(iii) encouraging parish and town councils to be proactive by preparing flood plans and forming local flood action groups to help in response to flooding events;

(iv) a guide has been published jointly, titled `Managing Flood Risks in Parishes' A Best Practice Guide. The take-up throughout Hampshire has been good and the guide is being promoted nationally;

(v) catchment liaison meetings to get feedback from local communities and deal with local issues relating to the catchment;

(vi) a series of seminars for Parish, District and County Councillors to highlight the issues; and

(vii) production of a video made as a joint project, highlighting flooding issues, responsibilities and how local communities and the public can help prevent and prepare for flooding.

Recommendation

That this report be noted.

7912/KFr