Do I need to hire a guide for St Clairs Falls.

You absolutely completely do not need to hire any sort of local guide to see the incredibly majestic St Clairs Falls. It is universally referred to as the Little Niagara of Sri Lanka specifically because it is massively wide and highly prominently visible directly from the main Hatton to Talawakele highway. There is a beautifully constructed highly safe dedicated viewing platform located right next to the road where you can effortlessly park your car and take phenomenal unobstructed photographs entirely for free.