48-hour restoration project on Dry Creek

WE ARE NAPA COUNTY

FLOOD CONTROL AND WATER CONSERVATION DISTRICTWatershed Management and Stream Maintenance

Napa Bridge

48-hour restoration project on Dry Creek

When "lots of rain, high water flows and a clogged waterway" meet "vigilance, out-of-the-box thinking, teamwork between the Flood District and property owners, and responsive contractors," good things happen.

The last week of November 2012 brought three consecutive storms and plenty of rain to Napa County.

By Sunday, Dec. 2, property owners along Dry Creek just south of Hwy 29 noticed that a large tree, downed by the storms had fallen into the creek and a lot of woody debris, brought downstream by these first large storms of the season, had combined to pose a very real flood threat to the neighboring properties.

Ordinarily, flood district crews would work to dislodge and remove the tree and the debris to open the waterway.

This time, they did that, but also much more. 

The results:

  • A free-flowing creek, with the banks stabilized by the tree trunk, newly planted native vegetation, and chipped debris. 
  • Enhanced habitat for fish and other species.  
  • More natural physical processes and flows in the creek. 
  • in less than 48 hours!

Before

After

Dry Creek restoration before Dry Creek restoration after

Here's how it came together: 

Sat. Dec.1: Property owners noticed a large

California Black walnut tree had uprooted from

the stream bank and fallen into and across

the creek. By Sunday, Dec., 2, a large debris jam

had accumulated behind the tree,  alarming

neighbors and potentially threatening property.

Dry Creek restoration after

Dry Creek restoration after

 On Sunday morning, Flood District staff talked with

 the property owner to evaluate the situation and

discuss strategies. First order of business:

Remove the debris jam.

 

Contractor Mark Dixon Engineering had been

staged at the Dry Creek Railroad Bridge, ready

to help if necessary during the storm.

Using an excavator, crews removed 93 cubic yards

of material that been clogging the waterway.

16 cubic yards was chipped and used onsite;

75 yards was hauled away.

Dry Creek removing debris

 

Dry Creek pulling tree

Flood District staff knew that tree, however, was a

valuable ecological resource.

 

Monday morning, with the property owner's

permission, crews from Pacific Tree Care

pulled the tree from the waterway and laid it

down on the bank, roots facing upstream,

to help keep the bank stable and to provide

more natural "complexity" in the creek.

 

  
  Dry Creek tree repositioned

Dry Creek tree repositioned

   

When the tree uprooted a large portion of the stream

bank was destabilized. To restore the bank and

streambed, the downed tree was positioned with

the rootwad facing upstream, the chipped flood debris

was spread along the top of bank, erosion control

fabric was installed along the bank, a willow mattress

was constructed at the toe of the stream bank, and

an assortment of native plants were installed to

stabilize the bank.

  

The project would not have been a restoration success without the willing cooperation and  

 support of the property owner. The Flood District considers downed trees (and their woody  

 debris) a highly valuable ecological resource to stream channels. The District works with 

 landowners to turn downed tree issue into habitat enhancement opportunities. In this  

 case the rootwad and 25 foot section of the main stem were preserved to protect  

 the streambank from future erosion and enhance instream habitat and  

 physical processes.