The annual Mermaid Promenade takes place this weekend in Downtown San Marcos this Saturday from 10 a.m. to noon. This all-inclusive city parade celebrates the history of the Aquamaids of Aquarena Springs and immortalizes the mermaid as guardians of the San Marcos River.  The parade line-up starts at the corner of CM Allen and Cheatham Street and offers plenty of viewing options along the route.  The fun continues at the Mermaid Aqua Faire immediately following the parade at the San Marcos Main...