Exeter new-builds: Drainage delays 'most common cause' for unadopted roads

Residents on several new-build estates across Exeter are facing indefinite private management charges as their roads remain "unadoptable" due to outstanding drainage issues.

While unadopted roads are frequently found on newer developments in areas such as Monkerton, Hill Barton, and Newcourt, Devon County Council (DCC) has confirmed it cannot adopt new infrastructure until specific technical standards are met.

The authority stated that a primary hurdle is the "unadoptable" status of highways where the underlying drainage has not yet been formally taken over by the water authority.

In many cases, adoption happens in phases, meaning some streets within an estate may be publicly maintained while others remain private pending completion of works.

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Devon County Council says there is no backlog of adoption requests in Exeter. 

In response to questions, the authority stated: “We actively respond to applications to enter into highway agreements, leading to the adoption of roads but cannot adopt new infrastructure until standards and preconditions (such as the separate adoption of drainage) have been met.”

Under the Highways Act 1980, the process must be initiated by the developer. Once planning permission is granted, the developer submits detailed technical designs under a Section 38 agreement for new roads or a Section 278 agreement for works to existing highways. 

These designs must meet Devon’s Standards for Highway Adoption and are approved by the County Council as highway authority.

The council has outlined the typical costs involved. Inspection fees are charged at six per cent of the bond value for Section 38 agreements and seven per cent for Section 278 agreements. 

The bond itself is calculated to reflect the total estimated highway construction costs and acts as financial security if works are not completed to the required standard.

Commuted sums, which are sometimes payable to cover the future maintenance of certain infrastructure, vary depending on what is being delivered and in many cases do not apply. Other administrative or technical charges may also be payable on a case-specific basis, such as the cost of preparing and making a Traffic Regulation Order.

Following approval of updated highway adoption standards by the council’s Development Management Committee on 4 February 2026, Devon County Council has confirmed that these costs have not changed.

A legal agreement is drafted once designs are approved and fees and bonds are paid. Construction is then inspected by agreement officers. 

When works are completed, certificates are issued and part of the bond is released. The roads then enter a maintenance period, often 12 months, during which the developer remains responsible for defects.

Only after that period, and following further inspection and any necessary remedial works, can the road be adopted. 

Crucially, Devon County Council says the most common cause of delay is drainage. Before a highway can be adopted, the drainage system must first be adopted separately by the water authority.

“The most common issue with adopting new highways is that drainage must first be adopted by the water authority and this process can sometimes experience delays,” the council said. 

It added that while it secures bonds from developers, which can be accessed as a last resort to bring roads up to an acceptable standard, it cannot do so until drainage has been adopted.

The position is illustrated by the Home Farm development. Devon County Council confirmed that the roads within the scheme have entered into a Section 38 agreement. 

However, drainage adoption has not yet been completed, as this is a matter for the water authority. 

The council said it is awaiting adoption of the drainage before highway adoption can proceed and noted that further remedial works may be required once the drainage has been addressed.

The issue was discussed at the Development Management Committee on 4 February 2026. 

At that meeting, councillors approved updated standards for highway adoption and agreed they should apply to highway and development schemes where the council is asked to adopt and maintain new infrastructure. 

Authority was delegated to the Deputy Director – Planning to manage publicity and introduction of the updated guidance, including making minor changes necessary during publication. 

Members also requested a workshop to discuss council guidance on new development transport connectivity and street design in response to the emerging National Planning Policy Framework and other relevant standards.

The debate about unadopted roads in Exeter forms part of a wider national discussion. 

The Ministry of Housing, Communities and Local Government is currently consulting on proposals to reduce the prevalence of privately managed housing estates in England, following findings by the Competition and Markets Authority that an estimated 1.75 million homes are now on privately managed estates.

For Exeter residents currently living on unadopted roads, however, the position remains governed by the existing legal framework. 

Devon County Council maintains that it supports developers through the process and that adoption cannot take place until technical standards are met and drainage systems are formally adopted. 

Until then, responsibility for maintenance remains private, even where roads appear complete and are used by the wider public.