In 2001, Monica and Michael Seybold bought a home in Nicasio, less than a mile from a shimmering reservoir on the edge of the Marin ranching community.
Over time, a hazard became increasingly apparent: Most winters, heavy rainfall floods a creek that flows through their backyard toward the reservoir. Sediment buildup has caused the creek bed — and the water — to rise further, they said.
“It got so bad in one winter storm that we had goats and they got themselves trapped, and Mike had to go out and swim each goat back up to land,” said Monica Seybold, who has raised three boys there with her husband…