He said: “Unfortunately just being a Site of Special Scientific Interest doesn’t necessarily protect the rivers from overdevelopment, from sewage dumping, from run-off from roads and agriculture.
“Because the national government is not doing enough, local authorities… are taking matters into their own hands and seeking ways to protect our natural resource.”
On 16 July, Southampton City Council, which helps to manage the Test and Itchen rivers, passed a near-identical resolution.
Lewes District Council and Basingstoke and Deane Borough Council have also previously acknowledged river rights.
Lawyers at Hogan Lovells, who worked on the Lewes declaration, said it was a “step forward” in protection.
However, they wrote, external: “Rivers and nature do not have legal personhood in England, or the corresponding right to sue and be sued in their own right.”
The wildlife trust said the votes “reflect a growing recognition that our rivers, and particularly our rare chalk streams, deserve stringent legal recognition and protection”.
Southern Water, which recently applied to increase the amount of water it can take from the Test, external in an emergency, said its long-term aim was to reduce abstraction through schemes including a new reservoir.
It said it was already spending millions of pounds in the Test catchment on upgrading infrastructure and improving the river’s health.
The Department for Environment, Food & Rural Affairs added: “The government has put down the building blocks to clean up England’s rivers.
“We are rebuilding the water network in one of the largest infrastructure projects in this country’s history, with a record £104bn investment to upgrade crumbling pipes and cut sewage spills in half by 2030.
“We will go further by creating a new, powerful water regulator responsible for the entire water sector – abolishing Ofwat and bringing together the water functions from four different regulators into one.”