Streambed Alteration Agreement (1600-2008-0118-R5) Regarding the San Dimas Wash Ivasive vegetation removal project (Project).

Streambed Alteration Agreement (1600-2008-0118-R5) Regarding the San Dimas Wash Ivasive vegetation removal project (Project).

The applicant proposes to alter the streambed and banks through the routine annual maintenance of 10.0 acres of soft-bottom channel within San Dimas Wash from San Dimas Canyon Road to where the concrete-lined channel starts to increase the rate and quantity of groundwater recharging along the creek. Project involves annual removal of non-native, ornamental, and invasive vegetation from the project site. It also involves removing debris , trash, and dead vegetation to prevent fire hazard issues and prevent these from going downstream during storms to the extent that is necessary to maintain flood control capacity of the channel. The applicant also proposes to maintain another small area within a stream entering the wash, outside of County's right-of-way belonging to the City of San Dimas. Clearing this area is necessary to ensure that debris and invasive vegetation will not block the inlet area. Ornamental trees such as eucalyptus trees will be cut down, and invasive plants including Castor Bean, Giant Reed, and pepper trees will be cut and sprayed with herbicide suitable for aquatic use. The substrate of San Dimas Wash will not be disturbed, and all cut plant materials will be removed from San Dimas Wash in a manner that will prevent the spread of noxious weeds. The Applicant shall not impact more than 10.0 acres of stream channel for routine maintenance activities to clear exotic (non-native) vegetation. No clearing of native vegetation is a part of this Agreement. The Creek will be allowed to passively revegetate naturally such that sufficient hydrology exists to allow for establishment of native riparian/wetland plant species. Annual reporting of the control invasive vegetation within the maintenance area shall be provided to the Department each year for five years. To avoid impacts to nesting birds the Applicant shall not remove vegetation from the streambed or bank or associated riparian vegetation between March 15 and September 15 unless otherwise agreed to by the Department. However, work may occur during this time if a qualified biologist conducts a survey for nesting birds within three days prior to the work in the area and ensures no nesting birds or their nests shall be affected by the Project. If an active nest is identified, a buffer shall be established between the construction activities and the nest so that nesting activities are not interrupted. The buffer shall be a minimum width of 150 feet, shall be delineated by temporary fencing, and shall be in effect as long as construction is occurring or until the nest is no longer active.

San Dimas

Los Angeles