I've just remembered a brilliant ford that could be done on a MEMWNS!
In Writtle, just after Bridge Street turns into Chelmsford Road take a right into a field and head towards the river. It does have a slimey bottom surface for tractors to cross, but other than that it is a completely off road unofficial ford. It will spew you out on a track heading towards Hylands Park.
I've been through it hub deep and sometimes had to go the long way round in winter when the river is somewhat swollen. It is off road, but nothing a suitably tyred, sturdy road bike couldn't handle. Just a thought for ford lovers.....
Edit: it has short but steep entrances which ever way you tackle it. Commitment is essential if you want to get out the other side. You will probably get wet in one way or another