Section 104 adoption is the process by which new sewers on a development are transferred into public ownership. It is a well-defined regulatory process with published standards, but the practical experience varies significantly depending on how it is managed. This guide walks through the process step by step, and complements our separate piece on what a Section 104 agreement covers.
Step One: Pre-Application Consultation
The first conversation with the water company happens before detailed design. The developer or their engineer submits:
Site location plan.
Outline masterplan showing plot layout.
Broad drainage strategy, distinguishing clean water and foul drainage networks.
Expected completion date.
The water company’s adoption team reviews and confirms:
Whether the site is within their area of responsibility.
The adoptable standards that apply (SfA 7 or equivalent).
Any site-specific constraints (for example, capacity limits at the receiving sewer).
Fee schedule.
This stage typically takes two to four weeks and is often free of charge.
Step Two: Detailed Design
The engineer produces detailed design drawings including:
Longitudinal sections for every sewer run showing levels, gradients, and manhole positions.
Plan view showing sewer layout relative to plots, buildings, and other utilities.
Manhole schedule with types, depths, and cover levels.
Pumping station design if applicable.
Catchment area calculation for pipe sizing, typically worked up alongside the new water mains residential design.
Materials specification.
The design must comply with the water company’s standards, which broadly follow SfA 7 but may have local variations.
Step Three: Formal Application
The formal Section 104 application is submitted with:
Detailed design drawings.
Structural calculations for manholes and pumping station.
Pipe sizing calculations.
Application fee payment.
Draft agreement or confirmation that the water company’s standard form is acceptable.
Proposed bond arrangements.
The water company’s adoption team reviews and responds within their published service standards, typically six to twelve weeks.
Step Four: Agreement Negotiation
The Section 104 agreement itself is a legal document covering:
The works to be adopted.
The adoption standards to which they must be built.
The inspection regime.
The bond value and form.
The commuted sums for any features requiring long-term maintenance provision.
The warranty period and defect liability.
Indemnities and insurance requirements.
The adoption trigger conditions.
Most water companies use a standard form, but amendments are often negotiated. Allow two to six weeks for legal review and signature.
Step Five: Bond Arrangements
The bond must be in place before construction begins. Options include:
Cash deposit (unusual because of cash flow impact).
Bank bond or parent company guarantee.
Insurance-backed bond from a specialist insurer.
Bond value is typically 100 to 120 per cent of the construction cost of the adoptable sewers. The bond is held until the end of the defect period, typically twelve to twenty-four months after adoption.
Step Six: Construction
Construction proceeds under the approved design. Key requirements:
Construction to the agreed specification, with no unauthorised variations.
Inspection by the water company’s adoption inspector at key stages.
Comprehensive record-keeping: pipe types, depths, testing results, CCTV surveys.
Variations approved in advance, not retrospectively.
Storage and handling of materials to preserve cleanliness and protect against ingress.
Most problems at adoption stem from poor record-keeping during construction, not from technical construction problems.
Step Seven: Testing
Each completed section of sewer must be tested. Standard tests include:
Air or water pressure test to confirm the sewer holds pressure.
CCTV survey to confirm the pipe is clean and free of defects.
Manhole visual inspection.
Pumping station performance test (if applicable).
Test results must be formally documented and submitted with the adoption application.
Step Eight: Completion and Adoption Certificate
Once all testing is complete and documentation is submitted, the water company carries out a final inspection. If satisfactory, they issue a Completion Certificate.
The Completion Certificate triggers several things:
Adoption of the sewers into public ownership.
Release of the developer from ongoing maintenance liability for the adopted sewers.
Start of the defect liability period.
Step Nine: Defect Liability Period
During the defect liability period (typically twelve to twenty-four months), any defects discovered in the adopted sewers must be rectified by the developer at their cost.
If defects are found and not rectified, the water company can call on the bond to fund the works.
At the end of the defect period, if no outstanding issues remain, the water company formally releases the bond.
Step Ten: Bond Release
Bond release is the final administrative step. The developer submits a bond release request. The water company confirms no outstanding issues and releases the bond.
On a well-managed development, bond release happens routinely twelve to twenty-four months after adoption.
On a poorly-managed development, the bond can be retained for much longer because of outstanding snagging.
Total Timeline
A typical Section 104 process runs:
Pre-application to signed agreement: ten to twenty weeks.
Construction: aligned with the build programme, often six to twelve months.
Adoption Certificate: six to sixteen weeks after construction completes.
Defect period: twelve to twenty-four months after adoption.
Bond release: end of the defect period.
Common Pitfalls
Late pre-application consultation. The water company’s adoption team has its own programme, and short-notice applications get queued.
Design revisions after submission. Each revision resets part of the review clock.
Unapproved variations during construction. These must be rectified or re-approved before adoption.
Poor test record-keeping. Missing CCTV surveys or pressure test certificates are a common cause of adoption delay.
Weak bond arrangements. Water companies may reject bonds from unfamiliar issuers.
The Bottom Line
The Section 104 process is well-defined and predictable if you follow the sequence, engage the water connections team early, build to the standards, and keep clean records. The common causes of delay are administrative, not technical. A development that manages the administration well adopts its sewers routinely and releases its bond on schedule. A development that treats Section 104 as an afterthought often finds the bond still outstanding years after practical completion. If you would like a quick appraisal of your scheme, request a quote.