Drainage and leak detection across West Sussex.

West Sussex is chalk-aquifer country at its most uncompromising. Every district served by Portsmouth Water or Southern Water draws on that chalk, and the resulting hardness – running from a hard 280 ppm in Horsham and Adur up to a very hard 330 ppm in Chichester and Worthing – is the single biggest driver of drainage and leak-detection callouts across the county. Scale deposits narrow bore pipes over decades, blind float valves, and conceal slow supply-line weeps behind what look, on thermal imaging, like simple cold surfaces. Before we diagnose anything in West Sussex, we are diagnosing it through the lens of some of the hardest mains water in England.

All visits are scheduled project work: booked one to two working days ahead, on-site between 9 am and 5 pm. This is not reactive cover – it is methodical, planned investigation and repair carried out by fully equipped two-person teams who have time to survey properly rather than patch under pressure.

Coastal and flood-plain districts

Adur and Worthing between them define the county's coastal drainage character. In Shoreham-by-Sea and Lancing, flood-plain positioning means that any drainage survey must account for the direction of failure as well as its cause: a blocked run on a flood-plain property does not simply back up slowly, it backs up fast when the water table rises. Adur's post-war estates – built in the 1950s and concentrated around Sompting and Southwick – are also running out of time on their original cast-iron soil stacks, which are now approaching or past their realistic service life. We CCTV-survey before recommending anything, because a stack that looks sound from the outside is often paper-thin at the joints.

Worthing's Victorian and Edwardian terraces, particularly in and around Tarring Old Village conservation area, carry a different risk profile: lead supply pipework still in service in a meaningful number of properties, combined with very hard Southern Water at up to 330 ppm. Lead softened by scale chemistry is a slow but real issue, and our acoustic correlation and tracer-gas work in these streets is as often about confirming pipework integrity for insurance purposes as it is about locating an active leak.

Arun extends from Littlehampton and Bognor Regis through to the historic market town of Arundel. The supply picture here is unusual – a dual-authority boundary where Southern Water and Portsmouth Water both operate, which can affect water-hardness readings depending on which main feeds a given street. Bognor's older Victorian seaside parade stock has a high incidence of failed back-inlet gullies, many original to the build, that cause standing water in front basement areas. Arundel's proximity to the Arun flood plain adds surface-water risk that requires its own assessment during any drainage survey.

Inland and rural West Sussex

Move north of the coastal plain and the picture shifts substantially. Chichester city centre sits within a conservation area that wraps around the cathedral and most of the pre-1900 building stock: any external drainage modification requires careful co-ordination with the local planning authority before a spade goes in. Petworth, covered under Chichester district, brings a further complication – some properties on the Petworth Estate run on private water supplies rather than Portsmouth Water mains, which changes the leak-detection methodology entirely. We switch from acoustic correlation against a pressurised public main to pressure-decay testing and tracer-gas tracing within the private supply network.

Horsham district spans a broad sweep from the market-town centre out through Billingshurst and Pulborough to genuinely rural territory. Period stock around Horsham town centre shares the cast-iron soil-stack problem seen in Adur; out towards Storrington and the South Downs fringe, properties run on private soakaways and, in some cases, septic tanks. A blocked soakaway in this part of the county is not a quick jet-and-go job – it requires infiltration testing, a check against any Environment Agency flood-zone mapping, and a clear picture of whether the soakaway can be rehabilitated or needs replacement.

Mid Sussex – covering Haywards Heath, Burgess Hill, and East Grinstead – is classic inter-war and 1970s commuter-belt stock: single-pile semis with kitchen extensions whose drainage was tied back to the original 4-inch clay runs. Those clay laterals, now fifty or sixty years old, are the most common CCTV finding in this part of the county: root ingress at joints, offset sockets, and the occasional collapsed section that no amount of jetting will fix. Where the pipe itself is sound in structure but cracked at joints, no-dig CIPP relining is our preferred resolution – it preserves the ground around mature garden trees and avoids the planning complications that open excavation can bring in conservation-adjacent streets.

Crawley stands apart from the rest of the county. Built as a New Town from the late 1940s, its drainage infrastructure was installed in a concentrated window between roughly 1950 and 1965 in uniform PVCu. That uniformity is, paradoxically, a vulnerability: a whole district's worth of drainage reaching the same age at the same time. Relining is already the standard response here, and the scale of planned renewal work in Crawley is significant. Its proximity to Gatwick also means we co-ordinate carefully on access and scheduling for any properties affected by airport operations.

Leak detection across the county

West Sussex chalk-aquifer water is hard enough that slow supply-line leaks frequently self-conceal behind scale deposits – the leak path mineralises over time and the visible dampness appears well away from the actual breach. Thermal imaging alone is insufficient in this environment. Our standard approach pairs thermal camera survey with acoustic correlation across the supply run, and where the signal is ambiguous – particularly in properties with original lead or early-era copper pipework – we introduce tracer gas to confirm the precise breach location before any floor or wall covering is disturbed.

Every leak-detection visit in West Sussex concludes with a written report carrying thermal and acoustic data logs, a marked-up floor plan, and a clear written statement of findings suitable for submission to a buildings insurer or a conveyancing solicitor. For pricing, see /pricing – there is no callout fee, and a fixed price is confirmed before any substantive work begins.

Coverage and scheduling across the county

All seven West Sussex districts – Adur, Arun, Chichester, Crawley, Horsham, Mid Sussex, and Worthing – are served as scheduled South-East coverage, distinct from our M25-adjacent footprint further north. Day-one slots book fastest in the coastal strip during spring and autumn when post-storm drainage assessments run heavy; inland rural visits to Horsham and Mid Sussex are typically easier to schedule at short notice. Planned survey and repair projects spanning multiple properties or multiple districts are co-ordinated through a single point of contact and scheduled as a programme rather than a series of individual bookings. If your requirement covers more than one West Sussex district, or crosses into Hampshire or Surrey, speak to us about a county-spanning programme schedule.