Drainage Design

We provide advice and design to ensure your finished project has fully compliant drainage, fit for purpose for the life of the property, including private drainage to adoptable sewers.

It is important to have house drains or main sewers that meet necessary design criteria before actual construction on site. This will save considerable time, effort and money at a later stage.

Why not give us the first opportunity to design your drains or sewers to meet the current design standards.

 
 
 
 

New sewers – Section 104

Normally new constructed sewers that form part of a development are dealt by an Agreement under Section 104 of the Water Industry Act 1991.

• We work in accordance with Design & Construction Guide for Developer – Sewers for Adoption (6^th Edition).
• We can design new sewers to an adoptable standard.
• Provide detailed sewer layout in AutoCAD format.
• Provide hydraulic and structural calculations.
• We can secure necessary Bonds associated with adoptable sewers.
• We can meet design criteria and obtain technical approval from the local water company.

 
Existing sewers – Section 102

In certain cases, an application for provision of serving existing and private sewers already constructed on site can make a declaration for an adoption under Section 102 of the Water Industry Act 1991.

• We can process and secure late technical submissions. This process is more stringent and difficult to approve for an adoption.
• We can demonstrate that sewers already constructed can meet design criteria and necessary approval and they are suitable for adoption as public sewers.

 
Sewer diversion – Section 185

Sometimes it is necessary to re-direct a public sewer across a site. Diverting a sewer away from the site and allowing a proposed development to take place is complex procedure and can only be achieved under Section 185 of the Water Industry Act 1991.

• In a simple diversion we incorporate this in the Section 104 Agreement.
• We can design and implement the necessary diversion of the public sewer without affecting the building or proposed development.

 
Sewer requisition - Section 98 to 101

If a proposed development with no means of drainage to the public sewer and the developer cannot agree an easement with third party land owner, the water company can requisition a sewer in private land (except Crown Land) to serve the site. The process of sewer requisition is normally made under Sections 98 to 101 of the Water Industry Act 1991.

• We can advise and achieve the objective either by negotiating with the landowner or by involvement with Water Company to requisition the sewer on behalf of the client.

 
Sewer adoption – Design

If new or existing sewers are already constructed on site, it is important to adopt the sewers without any delay. It is important to remember if the sewers are not adopted first, the road will not be able to be adopted.

• We can arrange to identify any necessary remedial works prior to the maintenance period or final sewer adoption stage.
• We can arrange to undertake any remedial works identified.
• We can serve the sewers for an adoption.
• Reduce bond associated.
• Minimise liabilities.

 
Highway drainage design

• We can check design submissions to ensure that a private or public highway drain has sufficient road gullies and is positioned evenly on the highway to ensure no flooding occurs on the road surface.
• This also includes a carriage channel and locating a suitable discharge point.

 
Building over or close to a drain

Before the construction of a development or proposed extension, it is important to check location of the public sewers. If the location of the public sewer does not prevent development or construction of an extension to take place, it may possible to enter into a “Build Over” Agreement.

• We can help manage the build over process with an approval with Building Control Section of the Local Authority and obtain necessary approvals from the water company.

 
Planning application appraisal

Before submitting a planning application to the Local Authority a key criterion is the means of draining foul and surface water from the site.

• We can help to assess proposed planning applications, examining them in detail to determine if the rate of discharge and proposed connection point meet the planning criterion.

 
Building regulations approval

When considering building an extension or making alteration to your property, the design may have an impact on the drainage system.

• We can help to build over or close to public sewer before building work commences.
• We can also advise on obtaining approval for provision such as new drains and manholes.

 
Sewer investigation

• We can carry out all types of detailed sewer investigation and accurately located systems on site.
• We can interpolate this data and producing drainage information on a plan to a suitable scale.

 
Sewer survey including producing ‘As Built’ plans

• We can organise and carry out sewer survey and produce ‘As Built’ plans to a suitable scale.
• The survey information includes position of manholes and any other attributes required by the Ordnance Survey.
• The survey information standard plans for sewer layout, plan view, profile view, cross section view, sewer surveys to form part of “As Built” drawings.

 
Manhole survey

• We can carry out a survey to produce the detail manhole survey which is a part of sewer adoption process.
• A typical manhole will come with ‘manhole attributes card’, giving a sketch in accordance with STC 25 compliant.
• The survey information comes with a hard copy of the manhole card, ST25 database and in DVD format.
• We offer our services to clients that require just a manhole record card and not a full survey.