Nigel Blacow BSc ARICS (who spent many years working at a senior level in the UK drainage industry) is a member of the Hoylake Vision Management Group. He writes:
We have been in dialogue with Wirral Council (WMBC) officers and councillors regarding this issue for over 12 months. There has recently been significant progress that we wanted to share with the community.
It is important to realise that these surface water drains, from nearby land and roads, were originally designed and installed to discharge through the sea wall, over 100 years ago. Currently, mainly due to beach level changes, over the years, the sand now covers the majority of these outlets. Also, because of the sand level rising, the tide does not come right up to the sea wall as frequently to wash away these discharges.
(Please refer to Appendix A for a more detailed explanation of the background, responsibilities and scale of these issues and Appendix B for an extract of Natural England comments regarding these drainage issues).
Our efforts fall into 4 broad areas:
- Longer term – diversion of these drains away from beach discharges.
- Short term – proper maintenance of these road gullies and surface water drains.
- Investigating and mapping all drains that discharge onto the beach.
- Establishing if the discharges are contaminated with raw sewage or other noxious matter.
The progress, under these headings, has been as follows:
- In the longer term – We have been arguing that these drains are no longer fit for purpose and a radical solution needs to be found, at the earliest practical opportunity. There appear to be two possibilities
- Divert the road gullies and surface water drains (WMBC responsibility) into the nearest sewer (United Utilities responsibility)
- Natural England have suggested that land drainage/ run-off could be collected, treated and then discharged via a regulated discharge point. There may be opportunities for wetland creation landward of Hoylake or further along the coast and these areas could receive this treated water.
WMBC have very recently acknowledged to us that there is a real problem here and that the need for a solution appears to have universal support. We are pleased to report that they are now actively looking at means to tackle it and secure the necessary funding at the earliest opportunity.
This is significant progress and may be tied into proposed Meols flood relief works. Clearly, any scheme will need to get all the necessary regulatory approvals, be subject to consultation and securing funding. Consequently, there can be no definite timescale for this but Hoylake Vision will continue to push this forward and where possible provide help and support to WMBC and other stakeholders and possibly to identify other means of funding these works.
- In the short term – It is important that these drains are properly managed to avoid flooding of nearby streets and property and to minimise any noxious discharges onto the beach. In past years the gullies and outlets have been cleared, generally using a combination of tanker extraction, high pressure water jetting and excavation of the sand covered outlets on the beach. Windblown sand and surface water silt fills these gullies and drains on a regular basis and as the sand level rises further, these will need ever-increasing attention to keep them properly maintained. This is unsustainable in the longer term. Sometimes, clearing these surface water drains results in a considerable plume of debris and noxious matter being discharged onto the beach and we are pressing WMBC to keep this to an absolute minimum to protect the ecology of the foreshore as well as for aesthetic reasons.
- Towards the end of 2019 we were advised by WMBC Highways Department that there was an intention to investigate and map all the relevant surface water drains when resources allow. However, partly due to other priorities such as flooding and Covid this has not been done. As a result of our recent involvement, we now have an undertaking that this will be started in the coming weeks.
- We have been told on a number of occasions that United Utilities are satisfied that the discharges are not contaminated with sewage but despite requests, we haven’t seen any test results. There is, in our opinion, a high probability that the discharges do contain detergents (which will affect the flora and fauna on the beach and lead to unpleasant pools forming) and oil, tyre rubber and silt from nearby road surfaces. We have also been assured that UU have checked the redundant sewers that served the old toilet block near the bottom of Trinity Road and that these have been capped off and are not leaking.
Appendix A: Surface water drainage (Primarily the responsibility of WMBC Highways Department)
Hoylake promenade was built in 1898 and the design included a number of surface water (i.e. Largely rainwater) drainage outlets through the sea wall. These provided an outlet for the road gullies along North Parade, some nearby roads and possibly surface water from some nearby properties. The road gullies are designed to trap sand, silt and debris and this needs to be ‘sucked out’ on a regular basis using a tanker.
If they aren’t cleaned out regularly enough, the gullies and the drains from them will block up and need to be jetted clear with high-pressure water, which inevitably discharges silt and debris on the beach.
As these gullies drain the nearby roads they collect oil, brake dust and tyre rubber (dropped by vehicles), litter, rubbish, grit, detergents, weedkiller etc. This can and does end up on the beach.
Originally, these surface water outlets were some 1-3metres above the beach level but over time the sand level has risen to the point where many of the outlets are now at or below the sand level. This results in restricted flow and many more blockages.
The higher, steeper beach profile also means that the tides do not reach the area close to the sea wall as often and so discharge and effluent from these drains are not washed away as frequently.
This leads to stagnant pooling which turns green and slimy, and proliferation of vegetation, notably close to the promenade wall and around the slipways, as well as along the seawall from Kings Gap to Red Rocks, possibly because of contamination by sewage but much more likely from detergent residues.
It is important to note that this vegetation is distinct from pioneer saltmarsh and dune vegetation which occurs as a result of natural coastal processes.
As the clay drains are now 122 years old, they are bound to have deteriorated at the joints between the pipes and there are possibly broken sections. This could explain some of the seepages of water through the sea wall in many areas, although this may also be from groundwater running below the promenade surface.
Historically, the promenade surface has been drilled and injected with cement grout, to try to minimise this groundwater movement and the resulting undermining of the support for the promenade surface.
Between Kings Gap and Red Rocks, there are numerous further drain outlets which will take surface water from roads and properties along this stretch of beach. Here, in particular (but may also be the case on North Parade!), there is also a risk that these pipes have had grey water drains (from sinks, washing machines, dishwashers etc) illegally connected over the years or even foul drains! These would add unwanted nutrients into the discharge and encourage the growth of algal slime and other vegetation.
There is no simple or low-cost solution to this problem. The sand levels will continue to rise and block more outlets. At the earliest practical opportunity, the surface water needs to be diverted away from the beach, to avoid further problems on the beach and road/ property flooding due to blocked drainage.
As outlined above, there appear to be two possible solutions, diverting the surface water into the nearest foul sewer (responsibility of United Utilities). There is a foul sewer along the side of North Parade furthest from the beach. However, this will discharge to a sewage treatment plant and UU will be reluctant to take a large quantity of additional surface water, as this would increase treatment costs. The practicality/viability of connecting the surface water drains into the sewer would depend on the relative levels of the respective pipework and large sections of the roads affected would need to be excavated, at considerable cost and disruption.
Appendix B: Extract of Natural England advice to WMBC (March 2020)
- Natural England is concerned about the land drainage being discharged to the foreshore along the promenade and that it may not be regulated. This is with regard to the quality of the water and risks of contamination, the ability to maintain the drainage due to natural accretion, the influence this is having on vegetation development and beach amenity.
- Natural England advises that the water quality should be tested to understand the contamination risks, better managed and regulated.
- Natural England advises that it would be better for the local environment for land drainage/runoff to be collected treated and then discharged via a regulated discharge point. There may be opportunities for wetland creation landward of Hoylake or further along the coast and these areas could receive this treated water.
Hoylake Vision 1 August 2020