Poseidon Water, a national leader in the development of water supply and treatment projects using a public-private partnership approach, furthered its commitment to protect and preserve San Diego’s coastal environment by assuming stewardship of the Agua Hedionda Lagoon in Carlsbad.The Agua Hedionda Lagoon encompasses over 400 acres of marine, estuarine and wetlands habitat teeming with hundreds of fish, invertebrate and bird species.