Trabuco Community Defense Project
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United States Department of Agriculture Trabuco Community Defense Project Preliminary U.S. Forest Environmental Assessment Service April • 2010 Interdisciplinary Team members discuss the Trabuco Community Defense Project. Trabuco Ranger District • Cleveland National Forest 1147 East 6th St. • Corona, CA 92879 Orange and Riverside Counties, California T.6N., R.5W. and T.7S., R.6W., SBM Trabuco Community Defense Project – Preliminary Environmental Assessment 1 The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance. (Not all prohibited bases apply to all programs.) 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USDA is an equal opportunity provider and employer. 2 Trabuco Community Defense Project – Preliminary Environmental Assessment Contents Summary………………………………………….…………...…… 5 I Introduction………….………………….…………………………………………… 8 Background…………………………………………………………………. 8 Purpose and Need for Action………………………………………………… 11 Proposed Action…………………………………………………..………… 13 Decision Framework…………………………………………………………. 13 Public Involvement…………………………………………….…………….. 13 Issues……………………………………………………………………….. 14 II Alternatives……..…………………………………………………………………… 16 Alternative 1 – No Action……………………………………………………. 16 Alternative 2 – Proposed Action ……………………………..………...…….. 16 Design Features (Resource Protection Measures) for Proposed Action……..……21 Alternatives Considered But Not Analyzed……………………………...……. 26 Comparison of Alternatives…………………………………….…………….. 27 III Environmental Consequences.………………………………………...…………… 28 1. Effects Relative to the 10 Significant Factors………….……………………. 28 2. Risk of Catastrophic Wildfire………………………….…..…………...….. 34 3. Air Quality…………………………………………………………...…… 42 4. Hydrology and Soils…………………………………………….…...……. 48 5. Fisheries…………………………………………………….…………….. 54 6. Wildlife………….………………………………………………..………. 56 7. Management Indicator Species………………………….….……..……….. 58 8. Sensitive Plants……………………………………………………...……. 60 9. Special Status Plants…………………………………………….…...……. 69 10. Scenery…………………………………………………….…………….. 74 11. Inventory Roadless Areas……………………………..…….…………….. 79 12. Wilderness………………………………………………….…………….. 81 13. Heritage…………………………………………………….…………….. 87 IV Interdisciplinary Team…………………………………………………..…………. 91 V References………………..…………………………………..…………..…………. 92 VI Appendices………..……………………………………….……………………….. 102 Trabuco Community Defense Project – Preliminary Environmental Assessment 3 4 Trabuco Community Defense Project – Preliminary Environmental Assessment Summary The Trabuco District Ranger on the Cleveland National Forest has completed an environmental analysis with an Interdisciplinary Team for the Trabuco Community Defense Project. This project involves modifying fuels within the Wildland-Urban Interface (WUI) for the communities of Rancho Carrillo, Rancho Capistrano, Decker Canyon, and El Cariso. The project is located in portions of T.6N., R.5W. and T.7S., R.6W., SBM within Orange and Riverside counties. Portions of the project area are within or adjacent to the San Mateo Canyon Wilderness. The proposed action will include 13 treatment units totaling approximately 465 acres. It is expected that the units outside of the San Mateo Canyon Wilderness can be mechanically treated. Units within this wilderness area will be treated with non-motorized equipment and non- mechanical transport. No new road construction is proposed by this project. Because the majority of the proposed treatment units are already accessible by roads, the use of existing temporary roads would be minimal. The overall need for this project is to treat portions of the Wildland-Urban Interface “Defense and Threat Zones” identified for the communities of Rancho Carrillo, Rancho Capistrano, Decker Canyon, and El Cariso. The purpose of these treatments would be to: • Reduce the threat of severe wildfires • Provide for firefighter safety by that could pose a risk to the people reducing flame lengths, radiant heat, and these communities by increasing wildfire intensities, and rate of fire defensible space. spread from wildland fires that might occur in the area. Key Objectives A key objective (purpose) of this project is to build on the current proposed Elsinore Peak fuel break project and the existing North Main Divide Fuel Break Project to create a continuous band of managed fuels to meet the Wildland-Urban Interface objectives noted in the Cleveland National Forest’s Forest Plan. Other key objectives include: • Managing the vegetation age-class in • Developing treatment methods the WUI to preserve the natural within the San Mateo Canyon diversity within fire-adapted habitat Wilderness that comply with the communities, and Wilderness Act. This action is needed because this project’s target communities are surrounded by wildland vegetation that is currently at high risk of catastrophic wildfire. Trabuco Community Defense Project – Preliminary Environmental Assessment 5 Vegetation Condition The vegetation on National Forest System (NFS) lands around the communities of Rancho Carrillo, Rancho Capistrano, Decker Canyon, and El Cariso are predominantly chamise, ceanothus, manzanita, coastal sage scrub, coastal live oak, and scrub oak. This flammable wildland vegetation is highly prone to wildland fires. In addition, the fuel loading within the project area is medium to high—creating hazardous conditions with high potential to sustain large, high-intensity fires. Past and current drought conditions have resulted in the die-off of older brush in many areas and below-average live fuel moistures. This resultant condition has further increased the volume of dead fuel and the potential fire behavior. Unplanned fire ignitions started by the residents of these communities, recreationists, and those that occur along California State Highway 74 present a substantial risk to people and the environment. Much of this land is immediately adjacent to residential development on privately owned land—both outside the Forest boundary and within private in-holdings. This action is consistent with the existing Cleveland National Forest Land and Resource Management Plan (Forest Plan) (USDA Forest Service, 2005, pages 116-118). Two Alternatives Two alternatives were analyzed in this environmental assessment, a No Action Alternative (Alternative 1) and a Proposed Action Alternative (Alternative 2). Alternative 1 – No Action Alternative Under the No Action Alternative, current management would continue to guide activities within the project area. No vegetation reduction treatments, mastication or prescribed burning would be implemented. Little to no community defense space around private property on National Forest System lands would be created. Therefore, the project’s target Wildland-Urban Interface communities would continue to be threatened by a high risk for catastrophic wildfire. Alternative 2 – Proposed Action Alternative The Proposed Action Alternative would include units with both mechanical and non-mechanical hand treatments—both of which could be followed by the burning of piles or “crushed” brush areas. The project design features and mitigation measures would assure that treatments meet other needs as defined in the Forest Plan—designed to minimize impact to resources. (A description of these measures is outlined in Chapter Three – Alternatives.) Not a Decision Document This environmental assessment is not a decision document. This document discloses the environmental consequences of implementing the two alternatives analyzed in detail. Based upon the effects of the alternatives, the Trabuco District Ranger will decide to: • Implement the proposed action, • Implement another action alternative that meets the purpose and need, or • Take no action at this time. 6 Trabuco Community Defense Project – Preliminary Environmental Assessment Given the purpose and need of the proposed project, the deciding official, the Trabuco District Ranger, reviews the analysis of the 1. No Action and 2. Proposed Action alternatives, as well as all public comment on this proposal, to determine whether to authorize activities to treat vegetation using mechanical treatment (brush crushing, mastication, and/or chipping), handwork, non-mechanical handwork, and/or prescribed fire. If vegetation treatment (under Alternative 2 – Proposed Action) were selected, the deciding official could determine: • Where and how many acres • The time periods for of each treatment would implementing treatments, and occur, • If, when, and how each • Design features that would be treatment project would be included with the treatment, implemented. The Proposed Action Alternative could impose impacts to: • Plants, • Wilderness, and • Wildlife, • Soils. However, with the implementation of the “mitigation measures” described in this document, the