What the LLFA expect to see The maintenance scheme should be provided at either full application stage or discharge of conditions stage. It should highlight what maintenance work will be done, how frequently and by who. It should be shown where necessary that an agreement has been made with those in charge of the maintenance. The maintenance requirements and frequency shown within Part D of the CIRIA SuDS Manual C753 are a good example of what should be provided.

 

Every surface water drainage scheme should include a stringent maintenance plan to ensure that the features are accessible and will work at optimum levels throughout the lifespan of the development. Without this maintenance, the reliability and efficiency of the drainage network will be affected and consequently the risk of flooding and damage to the surrounding environments will be dramatically increased. Therefore, a maintenance plan detailing; what maintenance is needed, who will undertake the work, how it will be funded, and at what frequency the work will be carried out should be provided. The majority of common SuDS features available have their maintenance requirements and frequencies outlined within Part D of the CIRIA SuDS Manual C753.

Often the most challenging part of design a drainage scheme is the adoption of features. Who will be carrying out the maintenance is very important, and there are a range of potential adopters. It is recommended that if you intend for the drainage of your site or ay features within the site to be adopted by a third party (e.g. Anglian Water, Thames Water, Essex Highways) that they are engaged early on in the design process to ensure that features meet the adoptable standards.

It is the LLFA’s preference that the drainage network and its accompanying SuDS features are adopted by a public body where possible to ensure lifelong maintenance. Where necessary, features may have to be privately adopted however this is not the most desired option. It should be assured and clear that the design of the features meets both the adopters design criteria and those specified by the LLFA.

On 1^st April 2020, Sewers for Adoption was replaced with the new Design and Construction Guidance within Appendix C of the Sewerage Sector Guidance (SSG) document. The DCG includes information on SuDS which can now be adopted by water companies under s104 of the Water Industry Act 1991, meaning they can be adopted through the same mechanism as pipes, manholes and pumping stations. The link for this document can be found here. In response to this Water companies such as Anglian Water have updated their specific requirements for SuDS adoption. Anglian Water’s response can be found

Whilst the DCG is mandatory to Water Sewerage Companies it is a choice for developers whether or not to offer their SuDS for adoption. It is strongly recommended that engagement is held with all potential adopters as early as possible. This will save time and money in the long run and will ensure that the surface water drainage scheme is able to meet both the LLFA’ and the adopting authorities criteria whilst being designed to a high standard.

Applications which have soakaways/features serving more than one household (for example, across two gardens) should refrain from assigning maintenance responsibility to homeowners, as in the event of neighbour disputes there is an increased risk of maintenance standards lapsing. Where homeowners are assigned to the maintenance of features, they should be given clear instructions on what needs doing, how it can be done, and how maintenance can be carried out on their behalf by any onsite maintenance company.

Compliance with the proposed maintenance strategy for a site will typically be required by planning condition. Additionally, the LLFA requests that yearly logs are maintained and are made available to the Local Authority upon request. There may also be occasions when compliance is managed via legal agreement in consultation with the local planning authority.

Educational signage and interaction with the local residents and future homeowners are a good way for ensuring features are maintained. If those benefiting from the features understand what the SuDS are there for and how they work, they may be more inclined to ensure that they are kept clean and in a good working order.