Defra have today published a summary of responses to their recent consultation on delivering SuDS and plans to change the current planning system (In England). https://www.gov.uk/government/consultations/sustainable-drainage-systems-changes-to-the-planning-system
A new study suggests that the contamination of drinking water by shale gas is due to faulty wells and not hydraulic fracturing.
A US report suggests that weak wells not fracking caused US gas leaks into water. This was reported on the BBC http://www.bbc.co.uk/news/science-environment-29206704.
The British Geological Survey, in conjunction with the Environment Agency, have published mapping showing the vertical separation between principal aquifers and potential shale gas source rocks. The mapping is intended for use in risk assessments to help identify, at a high level, the relationship between shale units and groundwater.
The data is available here - http://www.bgs.ac.uk/research/groundwater/shaleGas/aquifersAndShales/home.html and there is also a BBC news story which covers the release - http://www.bbc.co.uk/news/science-environment-28130982.
The implementation of Sustainable Drainage Systems (SuDs) has been held up as a significant way of controlling the risk of flooding due to property development, an issue of even greater significance following the UK’s wettest winter on record.
Under the Flood and Water Management Act 2010, Local Authorities are due to become SuDS Approving Bodies (SABS) who, once relevant parts of the Act are implemented, will review and approve drainage plans and strategies for development sites before any construction can start. The role of SABS is seen by many as playing a key role in the development of long term flood defence strategies.
However, Defra have once again delayed the implementation of the SABS and recently sent out letters to stakeholders stating that SABS will not be able to approve SuDS schemes on new developments from October 2014, as originally planned. They plan instead to make a statement in the summer which will set out its plans for the implementation of SuDS in “greater detail”.
Defra have said: “The Government remains committed to implementing SuDS at the earliest available opportunity, but not in a way that affects development. While several departments are working hard on this, it has become clear that we will not be in a position to implement Schedule 3 from October 2014, as we had hoped.”
It isn’t clear what Defra mean by “not in a way that affects development” but there remain some questions regarding the time and costs associated with design, implementation and management.
There are many arguments about the cost-benefit of SuDS, some maintaining that properly considered SuDS can be cheaper than conventional drainage. Whatever the case, whilst appreciating that there is certainly a need for development, recent history shows that implementation of sustainable flood risk solutions must be included and that the key to this sustainability is proper design and functionality. Implementation of such measures will also allow local authorities to adopt schemes with confidence.
The new delays mean that, whilst SuDS may continue to be included in development plans, they may not be optimised and that performance of the all-important long term management is by no means guaranteed. Amongst all this uncertainty we can’t get away from one key point; continuing to repair flood damage resulting from poor development practice is definitely not an option.
The fall-out from the current UK flooding situation is almost certain to involve renewed discussion of diverse flood management options including, amongst other options, the increased use of infiltration Sustainable Drainage Systems (SuDS). Flood management is always going to require a range of complimentary solutions and there is no doubt that infiltration of surface water into the ground is effective in mitigating against damaging surface water flooding in the right environment. But what about where there is a potentially hidden, and unassessed, groundwater flooding risk to land and property? Areas above Chalk and some sandstone aquifers are known to be susceptible to groundwater flooding but what about other, less obvious, areas where groundwater is in a thin or shallow aquifer or potentially connected to surface water and what about the impact that SuDS can have on these water levels?
There are an increasing number of tools to help assess the suitability of ground for accepting surface water drainage, but should we also be routinely assessing potential impacts as a result of potential increases in groundwater levels or modification of the groundwater regime?
In my experience there are mixed opinions on the need to address this issue but, bearing in mind recent events, I would be very interested to hear whether you see the issue of groundwater flooding as potentially significant and if so what measures are you taking to assess this? Is this an issue that you think will move up the agenda or is it a case of out of sight out of mind? Perhaps you have already experienced groundwater flooding impacts and if so how was this dealt with?
Below is a short briefing note which may be of interest.
Several insurers exclude groundwater flooding from their policies according to this article. http://www.telegraph.co.uk/topics/weather/10686446/Hundreds-of-flooded-homes-could-be-denied-insurance-payouts-due-to-groundwater-exemption.html
I have just checked my insurance policy - it may be time to do the same.