"We believe the young mare -- a trotter type -- had been trapped on a very small wooded area of higher ground, between the A3 and the river, for a day or two as the flood water around her had continued to rise and forced her further and further into the undergrowth," RSPCA animal welfare officer Carl Hone said.
"When we arrived we waded across the water -- which was extremely deep in places -- and could see that she'd been there for some time as she'd eaten the bark off all of the trees in the vicinity. We managed to carry some hay over for her and she devoured it; she was clearly hungry," he said.
Hone said the rescue team put a guide line across the water and attached one end to the pony's head collar.
"Thankfully, the pony was young and active and easily managed the short swim across the deepest section before finding her footing on the ground our side of the flood water," he said.
The equine was taken to a nearby boarding yard to dry off and rest from its ordeal. The pony was nicknamed Jemima Puddle Duck.
The RSPCA said the pony will be taken to a rehoming center if it is not claimed by owners within 14 days.
