The estimated project cost is $1.5 million funded by 60% federal Highway Safety Improvement Program (HSIPL) and 40% federal High Risk Rural Road (HRRRL) program.
This road safety improvement project is included in the 2009 Capital Road Improvement and Preservation Program (CRIPP) for fiscal year 2009/10 to 2015/16. The County proposes to realign and widen a 2,425-foot long section of Alhambra Valley Road east of Bear Creek Road to provide shoulders and clear recovery areas for motorists to regain full control of their vehicles should they veer off the traveled way. The project will realign the road and widen the existing travel lanes from 10 to 12 feet wide which will add 5-foot wide paved shoulders. This proposed section configuration meets County design standards, matches the dimensions of similar safety projects along Alhambra Valley Road, and significantly improves the function of the road as a Class III bicycle facility.
The project will also require cutting into the existing hillside slope along the north side of the road to accommodate the road realignment. The hillside will be cut at a 2:1 slope which requires removing approximately 4,000 cubic yards of soil from the face of the hillside (Option B). However, if it is determined from geotechnical investigations that this is not a stable option, a 250-foot long, 10-foot tall concrete wall will be constructed along the face of the hillside; this option will require removing approximately 1,500 cubic yards of soil (Option A). Approximately 12 roadside oak trees and 30 olive orchard trees will be removed to provide improved sight distance.
Existing roadside drainage ditches along the north side of the road will be recreated and lined with rock. In some areas along the south side of the road there are soft shoulders which will be re-graded to maintain existing sheet flow patterns off the road surface. Three existing sub-grade cross-culverts that convey runoff from the roadside ditches along the north side of the road will be extended or replaced to span the widened road. Culvert depth excavations will range between 2 and 8 feet. If necessary, rock slope protection will be placed at the outfalls of the culvert pipes.
One lane of the road will be open during construction; full road closure is anticipated for up to 2 weeks. Project construction will take approximately two months to complete. Construction is planned for 2013 and will occur sometime between April and October.
The project will not cause an increase in traffic or encourage changes to existing land use patterns; therefore no new vehicle trips are expected to occur.
The project area is located within designated critical habitat for Alameda whipsnake and California red-legged frog. Permanent and temporary impacts will be offset by off-site compensatory mitigation through a U.S. Fish and Wildlife Service and California Department of Fish and Game approved mitigation bank or to a land preservation trust that supports the creation, enhancement and/or restoration of Alameda whipsnake and California red-legged frog habitat which will benefit other species. Further, avoidance and minimization measures will be implemented to minimize impacts to special-status species and the natural environment. Removal of riparian oak trees will be mitigated as determined through consultation with the California Department of Fish and Game. Disturbed areas will be re-vegetated upon project completion.
The project will require property transactions such as right-of-way acquisitions for slivers of adjacent parcels at inversing curves to be realigned and temporary construction easements for work and staging areas; a slope easement may be required for the existing slope on the north side of the road that will be cut further back from the road (Option B). Otherwise, a retaining wall will be constructed (Option A). The proposed acquisition area is approximately 0.66 acre for Option A and 1.27 acres for Option B. The parcels adjacent to the project segment are designated as prime farmland and farmland of statewide importance. In addition, four of the parcels are under a Williamson Act Contract; the right-of-way acquisitions will occur on two of those parcels (365-020-035 and 365-020-039; D. & T. Powers) (Attachment G). The area of Williamson Act contracted lands that will be acquired will depend on the option selected; Option A would result in approximately 0.2 acre and Option B would result in approximately 1.6 acres. A map showing the proposed right-of-way acquisitions for both options are included in Attachment B.
The Williamson Act parcels proposed for acquisition currently contain grape and olive growing areas. The proposed areas of acquisition will require removal of up to 30 olive orchard trees; no grapevines are planned for removal. Disturbed areas within the temporary construction easements will be returned to pre-project conditions with the exception of the removal of the olive trees. While the olive trees will be removed, this area will not be acquired and therefore, farmland uses can continue after project construction. While no grapevines are anticipated to be removed, a portion the double-fenced pasture area and portions of a hedgerow and vegetable garden are located within an area that is dedicated for County road right-of-way purposes.
The policy of the state, consistent with the purpose of the Williamson Act to preserve and protect agricultural land, is to avoid whenever practicable, locating public improvements and any public utilities improvements in agricultural preserves. If it is necessary to locate within a preserve, it shall be on land that is not under contract. However, according to Government Code Section 51292(a) and (b) of the Williamson Act, whenever a public agency acquires land within an agricultural preserve it is required to make specific findings that the lower cost of the agricultural preserve land was not a primary consideration and there is no other land within or outside the preserve on which it is reasonably feasible to locate the public improvement. This project includes vital and targeted safety improvements to an existing road based on traffic accident data recorded at this specific location. Therefore, the proposed acquisitions are not based on a lower cost of agricultural preserve. Further, due to the presence of a creek located immediately adjacent to the south side of the road which is also adjoined by Williamson Act contracted parcels (365-020-036, 037 Serb et al.), there is no other land that is reasonably feasible to implement this public improvement as acquisition of alternate land would not achieve the goal of this safety improvement project. Therefore, the Board of Supervisors is being asked to make these findings by this Board Order.
As required by Government Code Section 51291(b), the County has notified the Director of the California Department of Conservation and the Contra Costa County Department of Conservation and Development of the proposed acquisition. The California Department of Conservation has concurred with the findings stated above (Attachment H). In accordance to Government Code 51291(c), the County will provide subsequent notification within 10 working days upon completion of the acquisition.
Delay in approving the project will jeopardize funding and delay design and construction.