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Community Development Agency, Transportation Division, recommending the Board consider the following:
1) Adopt the Draft Feasibility Study for Public Access to the South Fork of the American River at Mosquito Road Bridge; and
2) Direct Transportation staff to continue maintenance on the remaining segments of Mosquito Road in the event the Upper Level Alternative is approved for the proposed Mosquito Road Bridge at South Fork American River Project, CIP 77126 (est. time: 1 hour).
FUNDING: Highway Bridge Program Funds (100%). (Federal Funds)
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DEPARTMENT RECOMMENDATION
Community Development Agency, Transportation Division (Transportation), recommending the Board consider the following:
1) Adopt the Draft Feasibility Study for Public Access to the South Fork of the American River at Mosquito Road Bridge (Feasibility Study); and
2) Direct Transportation staff to continue maintenance on the remaining segments of Mosquito Road in the event the Upper Level Alternative is approved for the proposed Mosquito Road Bridge at South Fork American River Project, Capital Improvement Program (CIP) 77126 (Project).
DISCUSSION / BACKGROUND
Transportation staff is requesting direction from the Board on these two issues in order to proceed with the design and environmental review of the Project.
Summary of the Project: Transportation received federal funds to replace the existing Mosquito Road Bridge located in a steep canyon of the South Fork of the American River (SFAR), 6 miles north of U.S. Highway 50, and 2.3 miles south of the communities of Mosquito and Swansboro (see Exhibits A and B of the Feasibility Study). The purpose of the Project is to replace the existing bridge with a functional bridge that meets current design and safety standards. California Department of Transportation (Caltrans) and the Federal Highway Association Highway Bridge Program (HBP) have rated the Mosquito Road Bridge structurally deficient and functionally obsolete with a sufficiency rating of 12.5 out of a possible 100. Roadway approaches to the Bridge are also substandard due to a narrow, steep roadway, with 5 tight hairpin turns. Due to the approach conditions and the narrow width of the Bridge, emergency and larger commercial vehicles and trucks are unable to cross the Bridge.
Status: Transportation anticipates public distribution of the California Environmental Quality Act Environmental Impact Report (EIR) in September/October 2016, and Final EIR and Project approval presentation to the Board in late 2016 or early 2017. As presented to the Board on April 28, 2015 (Item 45) and to the public on July 15, 2015, Transportation narrowed the alternatives down to three: Lower Level, Mid Level, and Upper Level. The Board agreed with the concept that the Upper Level Alternative would best meet the goals and objectives of the Project, not only because it would be the Alternative with the least environmental impacts, but it would also eliminate the switchbacks on both sides of the Bridge. This Alternative is also overwhelmingly supported by the residents of the Mosquito/Swansboro community, especially given the safety issues of the existing Bridge location that were put to the test during the King Fire in 2014. As such, this Alternative is being studied in the EIR as the preferred alternative.
Mosquito Road: The Upper Level Alternative realigns Mosquito Road away from the switchbacks and the existing Bridge. Transportation has advised the Board that HBP does not fund existing substandard bridges and requires them to be removed from the County’s Vehicle Bridge Inventory once the Bridge is replaced. Unless outside funding (estimated cost of $12,500/year) can be obtained to keep the Bridge in place as a pedestrian facility, the County will be removing the existing Bridge once the new Bridge is complete. HBP can fund removal of the existing Bridge after it is replaced. The County Parks Division has already indicated it cannot take on the responsibility of maintaining this Bridge for pedestrian use. If outside funding is found for such an endeavor, it would be handled as a future project, entirely separate from this Project.
The existing road and bridge approaches on both sides of the Bridge would no longer function as part of the vehicular circulation system with approval of the Upper Level Alternative (see Exhibit B of the Feasibility Study). The question remains as to whether or not the road on either side of the bridge should be left in place and maintained, or abandoned. The 5 tight switchbacks are located north of the Mosquito Road Bridge. The road leading up to the south side of the Bridge is narrow, with no turnaround available; however, removal of the road could interfere with the ability to provide emergency services to this area and maintenance of utilities. Transportation, therefore, recommends installing gates on both stretches of road and continuing maintenance to allow for pedestrian access with vehicular access only for emergency and maintenance purposes. The estimated cost to the County to continue maintenance of these road segments is approximately $8,000 per year. Continual maintenance will preserve the prescriptive road easement.
Transportation requests direction from the Board to proceed as recommended and continue to maintain the remaining portions of Mosquito Road in the event the Upper Level Alternative of the proposed Project is approved.
Feasibility Study: California Streets and Highway Code 991 states that "Before any bridge on a county highway is constructed over any navigable river, the Board of Supervisors, after a study and public hearing on the question, shall determine and shall prepare a report on the feasibility of providing public access to the river for recreational purposes and a determination as to whether such public access shall be provided." The attached Feasibility Study provides this determination.
The Mosquito Road Bridge is located within an approximate ten-river-mile Class IV-V navigable section of the SFAR known as the "Slab Creek Run," that extends from Slab Creek Reservoir to Chili Bar Reservoir. In this section, the river follows a deep forested canyon that is usually not "boatable" due to flow controls. For comparison, the SFAR from Chile Bar west to Folsom Lake is Class II and III. The Slab Creek Run is managed by the Sacramento Municipal Utility District (SMUD) at the Slab Creek Reservoir, approximately 3.6 miles above the Project site. Flows are released through the Slab Creek Powerhouse into the SFAR to meet the minimum flow requirements prescribed under the Federal Energy Regulatory Commission (FERC) license.
During these limited flow release times, expert white water enthusiasts riding the Slab Creek Run, “put-in” at the informal river access location provided by SMUD located 3.2- river-miles above Mosquito Road Bridge. Many of these expert boaters choose to “take-out” on the south side of the Mosquito Road Bridge to avoid the Motherlode Falls located just downstream. Members of the expert Class IV-V whitewater boating community and the American Whitewater Association have expressed concern that this informal take-out that occurs during the SMUD recreation flow releases would be affected if the Mosquito Road Bridge is replaced.
Addressing the potential for new or improved river access at the Mosquito Road Bridge is the focus of the Feasibility Study. As discussed above, the preferred Bridge replacement alternative is the Upper Level Alternative which effectively reroutes Mosquito Road away from the existing Bridge. Vehicular access to the “old” road is proposed to be restricted via gates, but the paving would remain as County right-of-way. No changes are proposed to occur to the existing shoreline. Upon removing the existing Bridge, the suspension span components would be disassembled without impacting the river. The concrete supporting towers, short steel frames, and other bridge substructure would remain in place as a reminder of the old Bridge location.
Even though this area is used by expert boaters during high flow release times, the Mosquito Road Bridge is not an official boating take-out site. There are no public facilities or formal trails that lead to the river's edge. Steep vertically aligned canyon slopes, rocky, dangerous terrain and geographical constraints result in a site that is not conducive to supporting public access facilities. The Mosquito Road Bridge area has a history of landslides and sudden slope failures. Past landslides have closed Mosquito Road for prolonged periods of time and have required the construction of repairs such as soldier pile walls and rock netting to reopen the roadway. Most recently, a severe slide in 2006 led the County to declare an emergency and close Mosquito Road. With assistance from the Federal Emergency Management Agency, the road was reopened in 2007 after completing a $3,000,000 repair project.
During the relicensing process, SMUD also examined the Mosquito Road Bridge site for potential boating access. SMUD concluded there are too many site constraints prohibiting the development of suitable vehicle parking or boater access from the river without extensive construction, excavation, environmental impact and cost. In a December 15, 2015, email to EI Dorado County, SMUD stated it does not intend to develop the Mosquito Road Bridge site for recreational boating or other purposes, nor does it have plans to assume operations and maintenance responsibility for either the Bridge or the adjoining road approaches to the existing Bridge. River boating access facilities on the Slab Creek Run are already being developed by SMUD. Conditions under the new Upper American River Project licensing agreement require SMUD to develop a whitewater boating recreation plan for the SFAR below Slab Creek Dam which includes the provision of public recreational boating access and parking at Slab Creek Reservoir and at or near the White Rock Powerhouse.
Issues and potential impacts considered in the Feasibility Study are summarized below:
A) The County owns a prescriptive easement for Mosquito Road, but does not own the property or have rights to the areas outside of the paved roadway edges.
B) The County does not own the land adjacent to the river or have rights to the river, and as such it does not have the authority to grant access.
C) There is no adequate location to provide parking at either approach to the existing Bridge on Mosquito Road.
D) The County would need to acquire private land or expand the existing prescriptive easement on Mosquito Road to provide parking at or near the Bridge. The closest feasible location is on the south side of the SFAR, approximately one-half mile from the Bridge.
E) Due to the steep, rocky slopes between Mosquito Road and the SFAR, constructing pedestrian access would be extremely difficult, dangerous, and costly to build.
F) Potential environmental impacts, protection of riparian habitats and best management practices will need to be considered and comply with local, state, and federal regulations where applicable.
G) Construction of a river access facility would require purchasing easements or outright property, extensive maintenance, and ongoing costly repairs.
H) River access facilities would likely be within the Dam Failure Inundation Zone of the Chili Bar and Slab Creek Dams. Construction of a path, stairway, or any other associated facility would require review and permits from various agencies, including the Bureau of Land Management, U.S. Army Corps of Engineers, U.S. Fish and Wildlife, California Department of Fish and Wildlife, EI Dorado County, and others.
Transportation makes the following findings:
1) Due to physical constraints, potential environmental impacts, cost, safety, and other reasons cited in the Feasibility Study, it is not feasible or practical to construct additional public river access facilities as part of the Project at the existing Mosquito Road Bridge.
2) For safety reasons, once traffic is shifted to the new Bridge, vehicular access on the Bridge approaches (below the gates) should be restricted to maintenance, fire protection, emergency and other service vehicles.
3) Once the new Bridge is constructed, pedestrians will not be restricted from using the old Mosquito Road approaches. Existing informal river access will not be affected by construction of a new Mosquito Road Bridge.
ALTERNATIVES
The Board could choose to deny Transportation staff’s recommendation which would result in:
1) Failure to adopt a Feasibility Study would constitute a violation of California Streets and Highway Code 991 if the project is proposed to move forward.
2) The remaining segments of Mosquito Road could revert back to the property owners and limited vehicular access to the river would no longer be viable for emergency and utility purposes.
OTHER DEPARTMENT / AGENCY INVOLVEMENT
County Counsel has reviewed and approved the Feasibility Study. Various state and federal agencies would also be involved.
CAO RECOMMENDATION
Chief Administrative Office concurs with staff's recommendations.
FINANCIAL IMPACT
The Project is wholly funded with Federal HBP monies. No additional funding is being requested. Future maintenance costs are conceptual and will be brought before the Board for consideration and approval with the proposed Project at a later date.
CLERK OF THE BOARD FOLLOW UP ACTIONS
N/A
STRATEGIC PLAN COMPONENT
Infrastructure
CONTACT
Matthew Smeltzer, Deputy Director, Engineering
Community Development Agency, Transportation Division