Wednesday, April 24, 2019

Ventura River post-fire sedimentation 2019


Recent delta deposits in Matilija Reservoir, February 24, 2019




The Ventura River watershed is responding to the December 2017 Thomas Fire which burned the majority of the steep mountains in the headwaters.  In 2019, winter storms produced three significant flow events in the Ventura River.  These flows eroded additional sediment from the recently burned mountains and into the creeks and rivers.  Highway 33 above Ojai was closed following each event due to sediment overwhelming culverts and blocking the highway.  These photos of recent sedimentation in the Ventura River watershed were submitted with comments on a recent draft Matilija Dam Removal Sediment Transport Analyses report that is part of the ongoing Matilija Dam Technical Studies.




Matilija Reservoir, recent delta deposits March 11, 2019







Matilija Reservoir, recent delta deposits March 11, 2019
(note bubbles from submerged vegetation)





Matilija Reservoir delta, March 11, 2019
vegetation effects on sediment accretion and erosion
Matilija Reservoir delta, March 11, 2019
vegetation effects on sediment accretion and erosion
Matilija Canyon, Feb 19, 2019
Matilija Canyon, Feb 19, 2019





Sedimentation in North Fork Matilija Creek,
Wheeler Gorge Campground. Jan 29, 2019
Sedimentation at Ventura River Preserve, Nov 24, 2018
 Before: “swimming hole”  15+ ft deep
Sedimentation at Ventura River Preserve,  Feb 19, 2019
After: “swimming hole” previously 15+ ft deep

Sedimentation at Robles Diversion Dam, Feb 24, 2019
The facility was cleaned out at least twice to renew diversion capacity
from the Ventura River into Lake Casitas 


Ventura Rivermouth, January 22, 2019