After 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.

After measuring elevations on the ground as well as via aerial photography, the hydrologists were able to determine the main historic stream channels (shown in red) . The present entrenched stream channels are shown in blue. The present stream channel shows how the railroad berm (represented by the straight blue stream channel line in right third of picture) cut across the natural flow of Carman Creek. As it captured the stream flow, the resulting head cuts captured all the water that once spread out over the entire meadow. Without the historic flow the willows were dying and the meadow was converting to sage brush. The plan was to plug the current entrenched channel and divert the water back into the historic channel. The dark "blobs" represent the places that needed to be plugged. The earth needed to fill in the trench was generated by scooping out ponds and using that dirt to plug the channel.

The water enters the meadow from the left in the above diagram. The first plug creates a pond such that the outflow is directed into the historic channel. This was the entrenched channel about 15 feet deep and site of the first plug and pond. Notice the willows to the upper right.

The new plug has brought the water level back up to the historic level and diverted the outflow back onto the meadow. Those are the same willows. The spring of 2003 witnessed successful fledging of Canada Goose clutches at this pond and every other newly created pond. Wood Duck, Ring-necked Duck, Spotted Sandpiper, Red-winged Blackbirds, and Tree Swallows moved in for the first time to this immediate area.

The outflow, as seen in mid May, now runs back through the historic channel reviving the willows that were drying out. Now that the water is out of its trench, the water sheets across the entire meadow gradually revitalizing it.

The first plug is in the background to the right and this is the view of the stream running through the willows. The surface flow stops by mid June but the water table remains within a foot of the top of the pond. Throughout the remainder of the summer, the subsurface flow keeps the meadow wetter longer, maintaining the vitality of the willows. Despite the low bird populations in 2003 due to the May snow storms, more birds were captured in Carman Valley during August than in the past 11 years.

We monitor 6 different sites in the general region.  CAVA represents birds caught in this meadow at Carman Valley. The "4 sites" represents the average of 4 sites at higher elevations that are impacted by heavy snows forcing the birds into lower elevations during those years. RARA represents a 6th site in the adjacent watershed at a similar elevation. It was added in 1998 as a control to help assess the anticipated restoration. AHY means "After Hatching Year" a bander's code for all adult birds. Notice that the two years after restoration, 2002& 2003, more birds are remaining on the meadow. While Carman Valley shows a sharp increase, the control RARA shows a decrease suggesting  a restoration effect.

HY means "Hatching Year" birds, birds that were born that summer. Despite the overall decline in HY's in 2003 due to aborted breeding caused by the May snow storms, 2002 and 2003 held more HY birds than any other year but the flood year of 1997.

Because birds move around so readily, it is difficult to determine how factors  outside the study area effect the various bird  populations. Of all the birds we capture, Song Sparrows (SOSP) remain close to Carman Valley all year- arriving early and leaving late. Half of the 2 year-old SOSP's captured in Carman were born in Carman the year before. This is unusual for most of the species we catch. So SOSP's fidelity makes them one of our better indicators of factors affecting just Carman Valley.

More adults are remaining than ever before. Elsewhere their numbers declined.

And the number of HY's using the meadow in August has doubled relative to any previous "peak year". Elsewhere their numbers declined.

MacGillivray's Warbler (MGWA), one of the 2 most abundant breeding warblers did not breed during the drought year of 1992. The wetter, heavy snow years saw an increase in breeding  adults but as the meadow continued to dry out their numbers dropped precipitously. After restoration their number peaked 2002 despite a low snow year and remained high in 2003 despite adverse breeding conditions. Nowhere else did we observe such a marked increase.

Yellow Warblers (YWAR), our other abundant breeding warbler, showed marked increases in post restoration years Only in the two heavy snow years as birds were forced into the lower valleys, were more birds captured. YWAR's declined in the control site.

Although these species represent the best improvements, not all species have experienced such marked increase. However this is only the second year and they do represent our more abundant species. It is difficult to separate out natural cycles and lag effects. The U.S. Forest Service will continue to fund out monitoring for the next 4 years and we will be able to better determine the effect of restoration on our declining bird species. But the changes in the meadow seem so dramatic and beneficial, we suspect that restoring our wet meadows to their natural conditions could be one of the most significant improvements we can make to improve wildlife.

After Photos

View the before photos here.