Before the Restoration

The following is used, with permission, from Jim Steele's (San Francisco State University) web pages here, showing conditions and wildlife before and after the restoration.

(Above photo) The Carman Valley Watershed was extensively lumbered and grazed in the early 1900's. Railroad logging seems to be a major contributor to disturbing the natural hydrology. The loggers simply laid down railroads to wherever there was desired timber, then picked up the rails and moved to a new area. In this picture we see a remnant berm upon which the railroad was laid to raise the tracks above the historical wetlands. Dirt to build the berm was taken from the adjacent "borrow ditch". It was this ditch that then captured the stream flow that began the channelization process throughout the meadow. The dark water-line half way up the bank indicates where this ditch is draining the water table. The draining of the water table is partially responsible for the premature drying of this meadow as summer progresses.

(Above photo) As the natural stream flow was captured by the borrow ditch, the drop in elevation into the channel provided the stream with added force and turbulence which then undercuts the bank at the point of entry (the waterfall). The under-cutting of the bank causes the bank to collapse and then washed away. The whole process starts over again but the point of under-cutting is moved closer to the head of the stream. This is known as a head-cut. Here a check dam was used to capture sediment. However once the sediment was raised to the dams level the water worked around the check dam,undermining and collapsing it. This was not the historical channel but caused when the head cut worked its way up the meadow from the borrow ditch. The historical channel was on the other side of the willows in the background. New restoration will place the stream back in that historic waterway and fill in or block off this unnatural channel so it will not capture future water flow.

(Above photo) The head -cut worked its way through Knuthson Meadows in the pictures above and continue up the watershed to Three-corner meadows. Channelization like this exists up the entire watershed.

(Above photo) As the head-cut worked through the meadow, it also captured the flow of side streams. As they entered the channel they began the process of head-cutting new channels. Hear we see a side channel cutting across the meadow. Notice the young trees (approx. 50 years old).These water intolerant trees move into the meadow as the water table dropped.

(Above photo) Here is a section of stream in a relatively natural setting. Notice its width and depth. These relatively shallow channels can not capture large flows during the spring snow melt or major rain storms, but that is a good thing. When large flows leave the banks, it slows and spreads out over the flood plains, losing most of its power to erode the banks. This over flow also recharges the water table. Finally the shallow depth allows side ways flow into the meadows water table during the summer drought. Thus instead of a deep channel draining the water table the stream can maintain the water table for a much longer time and the meadow remains wet and productive throughout the summer. The wild life that is sustained by these flood plains in natural settings are often much greater than found in other adjacent ecosystems. The Sierra Nevada Field Campus has been monitoring the wildlife, particularly birds and bats, of this meadow since 1992. We will be able to document the changes to wildlife populations and vegetation as the meadow is re-watered when the stream is moved into its historic channels.

One hope is to bring back the endangered Willow Flycatcher. They have been observed here every year, even attempting to nest in the wettest year. Unfortunately the meadow is too dry and they move on. We speculate that once the meadow is re-watered they may stay and breed.

(Above photo) If left to its own devices the stream will once again create its own flood plains. However this will be much more narrow and confined to the newly created channel. Here we can see the beginning of this process. However the historic wetlands would be drained and not recharged. The new wetlands would be reduced to a small strand similar to this and over 90% of the historic wetlands lost.

To date our partnership has secured two grants, approximating $1,000,000, toward restoring this watershed. One from the EPA and one from the State Water Resources Control Board and NFWF.

After Photos

View the after photos here.