The last time Mt. Tamalpais had a major wildfire was in 1929. In 1930, Marin’s population was 41,648. Today it’s more than 258,000. … As with many other utilities, the Marin Municipal Water District is updating its treatment plants. It is unclear, from a technology and science perspective, whether our community treatment plant could handle sediment runoff from a big rainstorm after a catastrophic, climate-driven wildfire.