Healthspan has agreed to meet the £3,000 cost of recommissioning and the company will share the £25,000 annual running costs with the Little Extras Trust for the next three years.
The pool, which cost £200,000 to build, has not been used since October 2013.
It was closed in August the following year when the then Health and Social Services Department said the amount it was used did not justify the running costs.
The board agreed to the pool re-opening providing it was fully utilised and cost-neutral.
It was agreed to extend usage to all physiotherapy clinics and there is potential for charities such as the Guernsey Disability Swimming, the MS Society and Headway to have use of it for members.
'Healthspan is delighted to be able to support the use of such excellent facilities to help people who suffer from osteoarthritis, neurological conditions such as stroke, Parkinson's Disease, MS, or those recovering from injuries,' said chairman and founder Derek Coates.
