High-intensity chaparral fires cause increased erosion and sediment transport into streams, and this can be seen in the thick black sludge filling the Cold Creek channel. On my December visit, with no recent rain, the creek bed was pretty dramatically full of sludge.
December 30, 2015:
By my January visit, several small storms had contributed to small flows in the creek. As water washes the runoff from the burned hillsides through the system, ash from the fire as well as contaminants that were present on the hillsides will move through Cold Creek and into Putah Creek. This creates water quality concerns which will be addressed by future water quality monitoring to be conducted by the Solano County Water Agency.
January 8, 2016:
While the Cold Canyon trails are closed, the reserve is offering guided hikes to the public (current list of hikes). I participated in a hike at the end of December, led by Jeffrey Clary, Stebbins Cold Canyon Reserve Manager. We walked along the canyon trail, discussing the plants that were started to regrow, and how the site is faring five months after the fire.
Interestingly, there is less regrowth at this point than might be expected, with the hillsides still quite bare, with many fewer seed regenerating plants than after similar fires. That is not to say that there is no regrowth yet, though, and hikers found plenty of interesting plants along the trail, growing from seeds, bulbs, and resprouting from stumps.
We also observed other effects of the fire, including many new rock faces, created when the water inside the boulders caused them to explode in the heat of the fire.