School Park Preserve
Lincoln Creek Restoration

Auburn, CA

Envirocon, Inc.
Summer/Fall, 2007

Working with the U.S. Army Corps of Engineers, Placer Land Trust and the City of Auburn through Environcon, Inc., Hanford ARC was contracted to install Vegetated Soil Lifts (VSLs) along the banks of the recently reopened Lincoln Creek.  The daylighted channel was designed by Phillip Wililams Associates and features channel realignment, in-stream structures such as riffle-pools and step-pools, biotechnical bank stabilization (VSLs), and integration with other important elements of the proposed park.

Our portion of the project involved hydroseeding several areas of the site with specific seed mixes.; 19,340 square feet of terrace mix, 6,024 square feet of stream channel mix and 8,062 square feet of meadow seed mix.  Hanford installed approximately 2000 plants that required temporary irrigation to be in place.  Twenty overhead, popup sprinklers and 1800 emitters will water plants and hydroseeded areas until they are established. 

Several weeks before construction start, crews harvested 15,000 four foot willow cuttings and 2,700 three willow poles from a nearby source and stored them in a refrigerated truck to maintain viability.  These cuttings were then delivered to the site for installation in the VSLs.

Working with Envirocon, Inc., Hanford crews performed extensive grading and contouring of the banks, vegetative removal and then began the soil lift process.

VSLs are designed to stabilize banks by increasing plantable area.  The wrapping and staking of erosion control fabric and specific placement of rock further improve fluvial geomorphology.  The rapid growth of the willow stakes quickly stabilizes the bank while improving the aesthetic appearance almost immediately.