(a) Resource area. The resource area consists of the channel and banks of a wash, and those portions of the study area containing vegetative resources and wildlife habitat areas. Where alteration to any portion of the resource area is proposed, the applicant for a development permit is required to demonstrate why the resource area cannot be left in its natural condition.
(b) Alteration of resource area. No development, including grubbing, grading, removal of vegetation, channelization, or other type of alteration of the land, shall occur in the resource area unless a mitigation plan, which includes a plan for the proposed wash treatment and a preservation/revegetation plan, is submitted to the development services department director and approved as provided for in section 29-17 below.
(1) Mitigation plan. The mitigation plan must demonstrate that the loss of existing vegetation and wildlife habitat as a result of development in the resource area is minimized, and that lost vegetation and wildlife habitat are restored or recreated through the specific wash treatment and the preservation/revegetation plan. If a vegetated area is altered, the site must be revegetated to the same or greater density, diversity, and volume of vegetation as existed prior to the alteration. The mitigation plan shall demonstrate the following:
a. Wash treatment. The treatment of the watercourse must be done in a manner which maintains the existing appearance or predevelopment condition of the resource area by using one (1) or a combination of the following methods, in order of priority. Alternative structural solutions consistent with the intent of these regulations are encouraged and may be proposed by the owner.
1. Earthen channel.
2. Retention of stormwater runoff to reduce the impact on an earthen channel.
3. Structural materials conducive to retaining existing vegetation or revegetation, including any use of a soil filter blanket.
4. Compound channels.
5. Riprap, whether exposed or buried.
6. Gabions.
b. The following wash treatments may be used only if the city engineer determines that an existing safety hazard warrants such treatment, and the wash treatment method is approved by the mayor and council.
1. Rock veneer.
2. Soil cement.
3. Reinforced concrete, including textured, tinted, or colored concrete.
c. Preservation/revegetation plan. The preservation/revegetation plan must demonstrate that any vegetation removed from the resource area is replaced as closely as possible to the predisturbance condition in terms of plant type, density, and diversity. Plant types not currently existing on the site may be included in the preservation/revegetation plan if they are listed on the low water use/drought tolerant plant list in development standard 2-16. The preservation/revegetation plan shall contain the following information:
1. A preservation plan for native vegetation in the resource area.
2. The proposed location of vegetation after development, including the location of salvaged materials.
3. An access plan and maintenance schedule for the vegetation in the resource area.
(2) A copy of the preservation /revegetation plan shall be submitted to the development services department for review.
(Ord. No. 7579, § 1, 3-25-91; Ord. No. 9967, § 11, 5-17-04)