Complex sentence: In the Georgian era Hotwells was developed as a spa town in an attempt to compete with Bath, including the building of Dowry Square, but never really attained the same status, and eventually the waters were found to be polluted.
Split into simpler sentences: In the Georgian era, Hotwells was developed as a spa town in an attempt to compete with Bath, which included the building of Dowry Square. Despite this, Hotwells never attained the same status as Bath, and eventually the waters were found to be polluted.