By clearing the more than 1,200 acres of Arundo, the Natures Image team not only improved the water flow and sedimentation issues for the Matilija Dam location, the team also greatly reduced the fire risk in the area.
Case Studies
Matilija Dam
Restoration Project
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Las Virgenes Creek Rehabilitation Project
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San Felipe Tamarisk Eradication Project
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Summerly Mitigation Project
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Hill Canyon Wetlands Restoration Project
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Big Tujunga Wash Mitigation Bank Project
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Tonner Hills
Restoration Project
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Carden Academy
Reclamation Project
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Overview
Matilija Dam Restoration - Before work began.
The Matilija Dam is located approximately 16 miles north of the Pacific Ocean on Matilija Creek, which flows downstream from the dam for approximately 0.6 miles before joining the North Fork Matilija Creek and becoming the main stem of the Ventura River. Constructed in 1948 by the Ventura County Flood Control District, the original intent for the dam was to provide water storage for local agricultural use and for limited flood control.
Over the years, large volumes of sediment have been deposited behind the dam causing a number of serious issues including the reduction in the water storage, the obstruction of wildlife habitat and significant beach erosion.
The Challenge
The primary focus of the Natures Image team was the removal of approximately 1,200 acres of Arundo donax, Castor Bean, Scotch Broom, and Tree Tabaco. Removal of the vast amounts of unwanted vegetation required Natures Image to use specialized heavy equipment which created some concern within the local community.
The Solution
Natures Image worked very closely with Ventura Watershed Association to develop a restoration plan that would allow for the removal of the invasive plant species without contaminating groundwater resources.
In August of 2007, the team commenced with the first stage of Arundo removal. The reed-like plants were ground into a fine mulch utilizing a piece of specialized equipment designed to grind up large quantities of durable plants such as Arundo donax.
Arundo on site after herbicide.
The second and most sensitive stage of the project involved spraying the cut stalks of Arundo with herbicides. Because Arundo is so resilient, the plants must be cut down and then herbicides sprayed on the newly formed shoots.
This is the best method for the herbicides to reach the deep roots of the reedy plants. As with any project requiring the application of chemicals, Natures Images utilized only those herbicides deemed safe for use around all wildlife and approved by the EPA for application in or near waterways.
To allay fears of water contamination, the team conducted a series of tests at six different locations throughout the duration of the project. The water underwent extensive testing and the samples were monitored for temperature, pH, turbidity, dissolved oxygen, conductivity, glyphosate and non-ionic surfactants. The results of these tests were favorable and were communicated on a regular basis to community leaders.
The Results
The successful removal of vast areas of Arundo requires skill, patience and perseverance. Thanks to the experience of the Natures Image team, the Matilija Dam site is now clear of the invasive plant. Subsequent water testing has revealed no groundwater contamination and the aquatic habitat for the native fish in the area has been greatly improved.
Arundo removed and shredded on site.
By clearing the more than 1,200 acres of Arundo, the Natures Image team not only improved the water flow and sedimentation issues for the Matilija Dam location, the team also greatly reduced the fire risk in the area.
Matilija Dam is just one of many antiquated dams across the United States that has been targeted for removal to help restore rivers and recover endangered species. The work completed by Natures Image is just the first step in the process to preserve some of California's most precious natural wildlife.
