MOUNT TAMALPAIS (KPIX) — On Friday, fires roared to life on the slopes of Mount Tamalpais above Bon Tempe Lake but they weren’t wild — they were part of a plan to protect the woodland and keep Marin County drinking water clean.

“Today, we’re doing forest management or fuel reduction, as it’s called,” said Marin Municipal Water District maintenance supervisor Carl Sanders.

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Sanders’ crews are carefully burning piles of dead brush, reducing the fuel load above reservoirs in advance of the summer fire season.

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“We burn it this time of year — early spring — while the ground is damp, the grass is green and we are least likely to start a wildfire,” Sanders said.

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The water district says there hasn’t been a major wildfire on the slopes of Mount Tam since the 1940s and they want to keep it that way.