Police say they found the shooting victim in the Murrumbidgee River a short distance from the park, but after refusing to exit the river, he swam to an island and climbed a tree.
That kicked off a 12-hour police operation to get him down, eventually ending about 2am on Friday with his arrest.
He was treated in hospital, where he also faced a bedside court hearing on a charge of wounding with intent to cause grievous bodily harm.
The man has been refused bail. His alleged victim has been released from hospital.
Meanwhile, a taxi driver has been charged with reckless wounding after allegedly stabbing a passenger in the face.
Paramedics treated the 22-year-old male passenger for a stab wound in Paddington, in Sydney’s east, after the incident at 10pm on Friday.
He was taken to hospital in a stable condition.