1. Please can you confirm how much you have spent each year on surface water drainage from 2015?
Capital expenditure on surface water drainage is shown below. Please note that after 2021/22 all capital drainage works were delivered as a scheme related package of works meaning that we are not able to easily isolate drainage specific work to that of other elements of work. To establish this level of drainage granularity even as an estimate will require extensive resource investigation into every works order within each year after 2021/22.
2015/16 £2,129,000
2016/17 £1,176,000
2017/18 £1,064,000
2018/19 £1,776,000
2019/20 £1,328,000
2020/21 £1,605,000
2021/22 £2,144,000
2022/23 We do not hold this information as from 2022/23 onwards, the service has adopted an integrated approach to repairing roads including patching, drainage and other repair needs that were previously programmed independently. Individual elements of these capital works, such as drainage, are no longer budgeted separately and are delivered within the Local Asset Programme capital budget. For 2022/23, the total budget for these works was £13,485,000.
Identifiable revenue expenditure specific to cyclical works on SW drainage is shown below:
2015/16 £1,179,000
2016/17 £1,325,000
2017/18 £794,000
2018/19 £1,263,000
2019/20 £1,349,000
2020/21 £1,967,000
2021/22 £2,118,000
2022/23 £3,431,000
2. Please can you confirm if you have had issues with joint drainage systems, maintained by the water authorities that have not been maintained and led to flooding? How much has this cost yourselves to repair?
The issues with combined systems have generally been attributed to lack of capacity, particularly during extreme weather events. We refer you to further response in question 5 below.
3. Has a risk and threat analysis been carried out to see how much the ill maintained joint sewage and surface drainage systems within the sewage systems ( not on treatment plants or sewage pumping stations) are contributing to the flooding. From evidence in our area, these systems are not being owned by any parties and are collapsing and causing flooding?
Devon County Council, as the Lead Local Flood Authority (LLFA), carried out a Strategic Surface Water Management Plan for Devon to assess the risk of flooding from surface water and identify priority areas for further investigation. Detailed studies were completed for some locations to inform the design and implementation of flood improvements. The reports were prepared in collaboration with the Water Company and Highways to consider the local surface water and combined drainage systems. Copies of these reports are available on the Flood Risk Management’s website: Flood investigations, reports and studies – Flood Risk Management (devon.gov.uk)
4. Do you fully map all your surface water drainage and are you aware of which are owned by other parties eg the water companies?
The Water Company is required to map the locations of their apparatus, this information is then visible at request. In the delivery of any major highway scheme that involves excavation Highways and its partners will establish the locations of such apparatus from the Water Company. In terms of Highways drainage inventory we are able to provide the location of all our surface water gullies and have an inventory showing the size and location of our underground highway drainage. This inventory although incomplete is currently being added to as we become aware of new installations and through improvement works and CCTV are able to establish the detail of existing underground systems.
5. If flooding has occurred and is owned by other parties, what powers do you have to pursue and get these put right? How many enforcement notices have you issued to the water companies since 2015, in regards to the above issues?
Highways have an established working collaborative arrangement with the Water Company that is invoked when and if flooding related problem occurs on our highway network which it is suspected to be related to issues with Water Company drainage. In such circumstances, which are relatively uncommon, the Water Company will conduct their own investigations and report back on their findings. If it is determined to be a Water Company issue experience has demonstrated that the problem is rectified very quickly at their cost. In terms of enforcement notice the working collaborative arrangements we have in place mean Highways has no requirement to invoke an enforcement notice approach on the Water Company.
In terms of other private drainage where it is established that the problem is related to issues within the private system, such as a blocked outfall, Highways will work with the party concerned to remedy the issue. The Highways Act 1980 Section 100 provides the authority with powers in this respect.