Watch Hannah Pettifer's report here
A large protest against plans for a new crossing over the River Stort has taken place in Harlow.
The river, which used to be quarries and a landfill site, has been taken over by nature.
Members of the Friends of Latton Island group work to protect the River Stort.
They say if a large road was built there it would cause catastrophic, irreversible damage to the environment.
The road would link Harlow, which is in Essex, to a proposed 10,000 home development over the river Stort, which is in Hertfordshire.
Neil Warner-Baker lives on a houseboat on the river Stort. He spoke to us about the variety of animals which have made homes in and around the area of wetland.
The new crossing will be elevated on large culverts built on the wetlands, so the road spans the river.
The councils involved say the right balance needs to be struck.
The plans are still to be heard by East Herts and Harlow council.
Residents are being encouraged to submit their views before any recommendation on the crossing can be made.