large woody debris in the carmel river douglas smith, kelleen harter, lisa grady & paul...

Large Woody Debris in the Carmel River Douglas Smith, Kelleen Harter, Lisa Grady & Paul Huntington (Watershed Institute, California State University Monterey)

Larry Hampson, Beverly Chaney, Dave Dettman (Monterey Peninsula Water Management District)

Home page: http://hydro.csumb.edu

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Large woody debris providing

shade and predator roost at

low flow. This piece will easily

move with the next winter flow, so it’s

role will evolve.

Carmel River watershed

Cal-Am workers feed logs through San Clemente Dam 1998

Photo by Beverly Chaney (MPWMD)

How much is needed?How much is too much?

When does it destabilize a channel?

Benefits vs. Detriments?Dam removal effects?

•High priority sediment sources

Higher in the watershed there is perennial flow so wood can have an aquatic function all year long

Lower in the watershed the Carmel dries up leaving wood to perform terrestrial functions including rapid decay. The willows here are irrigated in dry months

Larry Hampson works with Paul Huntington and Kelleen Harter

Kelleen Harter

CSUMB students

Lisa Grady

Paul HuntingtonHampson for scale on a typical reach near Garland Park.

Seen any

logs?

Although it is clear that large woody debris plays critical roles in salmonid ecology and river morphology, there is still considerable debate about the quantity and geometry that optimizes those functions.

Sometimes it is easy to tell….

For example…here is too much large woody debris in a northern Mississippi channel :>)

Large woddy debris recruitment is a natural process. Banks are slowly eroded and trees fall in. In the context of suburban Carmel Valley, large woody debris is a now a liability. Trees like this huge sycamore can take down bridges! A paradox exists for watershed managers. This tree was dismembered and removed in December of 2002.

Photo by Larry Hampson

Larry Hampson stands one of several 40’ long redwood logs placed on the Carmel for fisheries habitat. After weathering about two decent winter storms in 2002/2003, the installations are performing exactly as planned.

Because naturally-recruited trees are a threat to infrastructure, anchored trees are now employed for habitat…at great expense!