December 5, 2014 12:40pm
• State will try mowing acres of water hyacinth
• The plants are clogging the California Delta
• VIDEO added 12/07
Now the California State Parks Division of Boating and Waterways will begin mechanical harvesting of the pervasive plant pest. A contract was finalized this week with Clean Lakes Inc. of Martinez, and harvesting will take place in areas most impacted by the hyacinth.
The focus of the mechanical harvesting will begin with a section of the Stockton Deep Water Channel from Weber Point to Buckley Cove in downtown Stockton.
A spokeswoman for the city says the recent storms have done a lot of the work. "The hyacinth is nearly all cleared out of the downtown channel. Between the earlier spraying and the recent storm, there are only a few pockets in the channel. However, it blew out further, so other areas are still obstructed," she says.
Other adjacent areas where water hyacinth has travelled and is impairing navigation will also be harvested, says the state.
"I am glad they are starting to harvest the plants; a day late and a dollar short is better than doing nothing at all," says Bill Wells. executive director of the California Delta Chambers & Visitor's Bureau. "They need to aggressively pull the weed out for the next several months and then spray herbicide during the growing season while continuing to mechanically remove the weed. The current invasive weed problem is the culmination of years of mis-management by the DBW. I feel it is going to take constant oversight by citizens in the Delta to keep them focused on the problem and make sure they do their job."
See the mean, marine weed eating machine in action here:
(Video by Roger Kelly)
Water hyacinth is an aquatic weed that is reactive to changing weather conditions. While it thrives in warm and dry weather, it can move and travel within waterways in rainy and windy conditions, and die off in hard freezes. Rain and wind can impact treatment, so harvesting will be conducted in infested areas if weather conditions are favorable.
“DBW recognizes the challenges with water hyacinth, and its impact to the public,” the department says.
It contends that new treatment methods and chemicals are “continually” being considered. Mechanical harvesting is an alternative treatment that is in compliance with federal environmental regulations to deal with the invasive aquatic plant.
The Division of Boating and Waterways conducted its annual herbicide treatment season for water hyacinth in the Sacramento-San Joaquin Delta from March through the end of November.
As of Nov. 26, says the department, the control program completed 561 herbicide treatments in 149 sites that cover the Delta, San Joaquin River and Tuolumne River. Approximately 2,500 acres of water hyacinth were treated with glyphosate and 2, 4-D.
However, there is no known eradication method for water hyacinth once it has been established. Thus, says DBW, it conducts a control program as opposed to an eradication program. The program seeks to minimize negative impacts of the invasive plant on navigation, public safety, recreation, agricultural activities and ecosystem services in Delta waterways.
Funding for water hyacinth treatment comes from the Harbors and Watercraft Revolving Fund, which receives revenues from boaters’ registration fees and gasoline taxes.