A no-deal Brexit could cause major disruption across Kent, with gridlock on the roads around Dover, rubbish not being collected, children unable to take exams and rubbish piling up on streets, a local council report has warned.

The registration service for weddings could also be affected and bodies could pile up in morgues because of traffic gridlock, Kent county council warned in an update on no-deal contingency planning. Problems would all flow from the congestion and new regulatory barriers that would be in place if Britain crashed out of the EU on 29 March.

In a 17-page report the council, which is expected to bear the brunt of a no-deal Brexit because of the critical Dover-Calais trade route, said it might have to deal with 10,000 lorries parked or stacked on its roads if the UK crashes out of the EU.

Under a multi-agency contingency plan codenamed Operation Fennel, freight traffic management would be put in place to move lorries away from the main arteries of the M20 and A20. The plan is to try to keep the main M20 open for normal traffic with contingency plans for 200 additional officers to mitigate disruption and enforce mandatory truck-driving breaks.

The county council update said it is also waiting for the government to take decisions about using Manston airport as a lorry park, which would be capable of handling 6,000 lorries at a time.

The document said if the worst-case scenario came to pass, it would inform everyone affected. Briefings for schools would be in place for January with travel plans for staff and children. Contingencies would also be made for school meals and air quality issues that may arise from congestion.

The council has also started to map social care workers and clients to try to address travel issues for vulnerable residents. Where possible council staff will be allowed to work from home for three to six months to reduce the burden commuting puts on transport infrastructure.

“The opportunity for staff to work at libraries, gateways and other KCC offices closer to their homes is being explored,” said the report.

The no-deal scenario planning also warned that customer service response times would be reduced in Kent. Civil service weddings could be affected as would spring visits to country parks.

“There are a number of service peaks around the 29 March 2019 period that could be impacted. For the registration service, there is generally an increase in weddings in April to June, and registrar involvement in these is likely to be affected by severe traffic congestion,” it warned.

“KCC’s country parks, which are almost 80% self-funding from customer income, historically have brought in strong income during the spring period when the traffic disruption could be at its highest,” it noted.

The coroners’ service, it said, “could face difficulties with the transport of the deceased to postmortem or body storage facilities, [as could] the attendance of staff to hospital sites for identification purposes and travel by pathologists to mortuary to conduct postmortems. Whilst mitigation measures are being explored, there are limited options available to this service”.

On waste management, it said: “District and borough collection services may be delayed and disrupted if there is significant traffic congestion.”

But it warned that Kent is somewhat in the dark “awaiting details of the government national freight plan”, including plans for passenger freight priorities and the “national ports strategy”.

It reiterated warnings from Kent council leaders before the Tory party conference that congestion from Dover would not just mean a disruption to Britain’s manufacturing supply chains. Roads near the main arterial routes in Kent would become congested as truck drivers sought alternative routes, potentially affecting everyday business and social services.

In September, council leaders warned the government’s no-deal Brexit plan could cause 14 days of chaos, drawing from the experience of the gridlock in 2015 caused by disruption in Calais.

• This article was amended on 21 December 2018 because Manston airport would be capable of handling 6,000 lorries at a time, not 1,000 as an earlier version said.