On a picturesque summer afternoon, West Basin Municipal Water District officials chose to woo regulators with a stroll by the beach in El Segundo, stopping to admire an unadulterated strip of California coastline.  “It is beautiful,” said Diane Gatza, West Basin’s water resources engineer. A few hours later, environmental advocates held a town hall two miles away in Manhattan Beach. “The reason we’re here is West Basin Municipal Water District is proposing a … desal plant,” said Bruce Reznik, head of Los Angeles Waterkeeper.