"There are concerns regarding debris, flow, and impact of water flow and potential for erosion and that impact onto our highways and roadways," said Doug Binnewies.
The Mariposa County Sheriff-Coroner says navigating the narrow roadways with rainy or winter weather can be difficult enough, but when you add the erosion from fire ash and debris clogging or overflowing drains, roadways can begin to flood.
He says they are most concerned about State Route 140 and 49.
Public Works crews say from the moment the Detwiler Fire ended, they have been working to clean ditches and create barriers along roadways to prevent stormwater systems from clogging.
"We're preparing through our stormwater prevention plans and the likelihood to put some measures in place that will filter those soils sticks and rocks from the stormwater system itself so that the system works well and can get the water away from road infrastructure 45," said Mike Haaly.
County workers along with Cal Trans will still be out monitoring the hazard areas throughout the week, but authorities say it is important to be extra cautious while driving in these areas this weekend and advise people to be aware of their surroundings.
"This is reportedly our first winter storm and were looking forward to that of course but there's going to be some unknowns," said Binnewies.