June 2006: GRCC staff lobbies Department of Fish and Game representatives for funding as everyone gazes at the massive slide along the lower reaches of Mattole Canyon Creek.

The finished product! After four weeks of heavy equipment work the site is complete. A large tree with its root ball attached is cabled into the rip rap wall to create fish habitat. In the lower right corner of the photo, parallel willow baffles protect the streambanks. Also, the terrace in the upper right corner of the photo was constructed to divert surface erosion off the slide onto a stable floodplain downstream.



This photo was taken along a segment of old logging road in the Ancestor Creek watershed near the headwaters of the Mattole River. Runoff from the old road was disturbing natural groundwater infiltration and causing erosion.



This photo, taken from the same location as the one directly above, shows how the road was re-contoured during a GRCC implementation project in 2007. This treatment technique prevents surface runoff concentration and improves groundwater recharge.

Another sediment sources in the Ancestor Creek watershed is evident where a small stream was cutting a gully through road fill.



This photo, taken from the same location as directly above, illustrates the large volume of material that was excavated from the stream channel and stored at a stable location nearby. The new channel was armored with cobble found at a nearby rock outcropping and the slopes were mulched with brush and rice straw.

This Photo was taken approximately 50' upstream from the inlet of a very old 36" culvert (inlet hidden by logs and brush) just before implementation work began. This crossing threatened to wash out during all large storm events, and impeded fish passage.

Heavy equipment was used to remove road fill so the new crossing structure could be installed at the gradient of the original stream channel.

Two footings were poured with a total of 28 cubic yards of cement. Then an arch culvert with 12' width and 70' length was installed. Here, the operator places rip rap around the inlet and outlet of the arch as the road surface gets rebuilt with compacted fill.

The finished product! Extensive riprap rock was used at this site to stabilize the channels where the road runoff from the inboard ditches drained into the creek. The site was mulched with rice straw and then later planted with Douglas fir seedlings.

This photo shows a typical "shotgunned" culvert. Such culverts often cause significant erosion below their outlets where the falling water carves out enormous holes in the stream channel and often leads to unstable road fill.



This photo was taken from the same angle as the photo directly above, and demonstrates important philosophies in GRCC culvert upgrade techniques. Significant riprap is placed below and around the culvert outlet to dissipate the energy of the water leaving the culvert and to stabilize the road fill. Also, the crossing was reconstructed with a stable fill slope by realigning the road to follow the contour of the land.