The Reserve Paddock on Isla Nublar was a large, yet to be inhabited, animal range surrounded by 24 foot, 10,000 Volt fencing. Though it would have eventually held several of the Isla Nublar 15 Species, at the time of Jurassic Park it did not.
Though there were no animals being held inside the Paddock, at least to inGen‘s knowledge, power was still being supplied to the fences until Dennis Nedry shutdown Park Security during the inspection. Power was later successfully restored by Ellie Sattler but it is unknown if there was any damage to the fence via escaped animals or the tropical storm.
