6. Significant Environmental
Impacts and Mitigation
6.1. Summary
Under all of the alternatives, the proposed project would have significant and unavoidable adverse impacts on agricultural resources and on cultural resources. In addition, Alternative 3 would have unavoidable significant adverse impacts on biological resources, and Alternative 3A would have additional adverse impacts on aesthetics and land use, planning and policies as compared to Alternative 2.
Under the "no project" alternative, the proposed project would not be implemented and, therefore, no adverse environmental impacts would occur.
6.2. Agricultural Resources
Construction of Alternative 1's new permanent access roads and placement of 114 new poles and lattice towers would permanently disturb approximately 31.9 acres of farmland, including 16.8 acres of "prime farmland," 0.7 acres of "unique farmland, and 14.4 acres of `farmland of statewide importance'" as defined by the Department of Conservation Farmland Mapping and Monitoring Program. A variety of crops are currently grown within these 31.1 acres, the most common of which are oranges (13.8 acres) and walnuts (5.0 acres), which would be permanently disturbed by this construction.
Although agricultural uses, including hundreds of dairies and thousands of acres of citrus and walnut groves, still dominate Tulare County's landscape, the County has seen a reduction in agricultural land to due urbanization, with a reduction of 12,355 acres of farmland between 2004 and 2006. The acreage of farmland in Tulare County is generally expected to continue to decline, and Alternative 1 would contribute incrementally to it.
As mitigation defined in the EIR, SCE would be required to obtain an acre of agricultural conservation easement5 for every acre of prime farmland, unique farmland, and farmland of statewide importance6 that is permanently converted. While this mitigation would reduce the impact of the conversion of farmland to non-agricultural uses, Alternative 1 would nonetheless result in the permanent conversion of farmland and contribute to the decline in farmland acreage in Tulare County. This impact to farmland would be significant and unavoidable.
As with Alternative 1, construction of roads and new pole sites for Alternatives 2, 3, 3A and 6 would permanently remove farmland to non-agricultural use. This impact to agricultural resources would be significant and unavoidable. The following table sets forth the amount of farmland acreage that would be permanently removed from agricultural use, by alternative:
Alternative |
1 |
2 |
3 |
3A |
6 |
Farmland acreage |
31.9 |
25.6 |
18.2 |
21.8 |
31.6 |
The draft EIR preliminarily determined that, under all alternatives, the proposed project would require the removal of walnut trees from the new portions of the rights of way, which would cause a further significant and unavoidable impact to agricultural resources. Specifically, under General Order 95, shrubs and trees located within a right of way under transmission lines must be maintained to not exceed a 15-foot height. The draft EIR determined that, while orange and other citrus trees can remain productive when cropped to this height, walnut trees cannot. Consequently, the draft EIR determined that the proposed project would effectively convert walnut acreage located in the new rights of way to non-agricultural use. However, upon further analysis in response to comments, the final EIR determined that this significant impact can be avoided by increasing the height of the transmission line to allow for a maximum walnut height of 30 feet. (Final EIR, at G-17 - G-18.)
6.3. Cultural Resources
The Big Creek 1-Rector and Big Creek 3-Rector 220 kV transmission line and the Rector Substation are part of the Big Creek Hydroelectric System Historic District (Historic District). The generation and transmission facilities of the Big Creek system date between 1911 and 1929, and are eligible for listing in the National Register of Historic Places and the California Register of Historic Resources. The Rector Substation was constructed at the same time, and is eligible for listing in the California Register of Historic Places.
Alternative 1 would require demolishing and removing approximately 26 original single-circuit lattice towers within the transmission line right of way. In addition, this alternative would require demolishing and removing original 220 kV transmission line towers from the Rector switchyard, installing a tubular steel pole and adding a pre-fabricated metal mechanical and electrical equipment room adjacent to the substation building. These activities would adversely impact the facilities' physical characteristics that qualify them for inclusion in the California Register of Historic Resources. Although SCE would document the adversely affected components of the Historic District prior to their removal, which would lessen the impacts, the impacts would remain significant and unavoidable.
Approximately 10.8 miles of Alternative 2, 14.6 miles of Alternatives 3 and 3A, and 8.1 miles of Alternative 6 would be located within the Big Creek 1-Rector 220 kV transmission line right of way. All four alternatives would have similar significant and unavoidable impacts to this component of the Historic District as Alternative 1.
When considered in combination with other future projects, the proposed project's incremental contribution to impacts to the Historic District would be significant and unavoidable.
6.4. Biological Resources
Alternatives 1, 2, 3A and 6 would have less than significant environmental impacts, or have significant environmental impacts that would be reduced to less than significant levels with the incorporation of mitigation measures, in the area of biological resources.
Under Alternative 3, the subtransmission line would traverse a portion of the Stone Corral Ecological Reserve that supports more than three acres of vernal pool habitat where the existing Big Creek - Rector lines traverse the reserve. The removal of existing facilities, installation of new lines and the creation of access roads would directly impact more than three acres of northern claypan vernal pool habitat that is within designated critical habitat known to support special status plant and wildlife species. Project activities could permanently alter local hydrology in adjacent vernal pools with compounding indirect project effects on wetlands and water flow in surrounding portions of the reserve. While impacts would be reduced with mitigation, they would remain significant and unavoidable following mitigation based on the extreme sensitivity of the Stone Creek Ecological Reserve to disturbance.
6.5. Unique Adverse Impacts
(Alternative 3A)
The final EIR identified the following unique adverse impacts of Alternative 3A that have the potential to be significant: Alternative 3A would place the transmission line right of way within 50 feet of four private residences and surround a business on three sides, it would bisect several agricultural parcels contrary to sound land use planning practices, and it would encroach on a proposed development shown in Tulare County's draft General Plan.
Given its unique adverse impacts and modest reduction in impacts to farmland (Alternative 3A would remove 21 acres of farmland, which is only four acres less than the environmentally superior Alternative 2 (see Section 7, below)), the final EIR determined that Alternative 3A was not likely to provide a superior benefit over Alternative 2.
5 An agricultural conservation easement is a voluntary, recorded agreement between a landowner and a holder of the easement that preserves the land for agriculture.
6 All subsequent references to "farmland" refer specifically to combined prime farmland, unique farmland and farmland of statewide importance.
