A new block of eco-toilets is due to open to the public in Street.
The toilets at Southside car park harness rainwater in an underground tank for cleaning and flushing.
They also have a permanent connection to a mains water supply so if a rainwater tank becomes empty, the mains supply automatically operates.
The new facilities are much bigger than the previous ones and offer better disabled access, baby-changing tables and toddler seats.
Over the past three years Mendip District Council has built new public toilets in Wells, Shepton Mallet, Glastonbury and Frome.
Street's new toilets are one of three blocks in the district to use rainwater for flushing and cleaning. Others using the system are at Glastonbury and Frome.
In 2006 Shepton Mallet's new facilities in Commercial Road were voted best non-attended public toilets in England at the National Loo of the Year awards. Others in the district were given five and four star ratings.