When Tom Becker and Marty Merkley encouraged Carol Rausch to weave Chautauqua’s weekly themes into Chautauqua Opera Company’s programming, one possibility stood out above the rest.

“ ‘Water Matters’ was an easy one to chime in on,” said Rausch, music administrator of Chautauqua Opera. “There is tons of repertoire about water. We could do this theme for another three to five years and not run out of material.”

At 8:15 p.m. Saturday evening, the Amphitheater hosts the annual Opera Highlights concert, titled “Water Matters — Operatically (H2Opera),” a hodgepodge of operatic favorites performed by Chautauqua Opera’s apprentice artists and the Chautauqua Symphony Orchestra. The program includes selections from shipwrecked islands, arias sung by water sprites and songs about the sea. It preludes the “Water Matters” morning lecture platform.