Rehabilitate Crane Flat Campground - Phase 2: Loops B/C/D & AABAS Accessibility Upgrades

Yosemite National Park » Rehabilitate Crane Flat Campground - Phase 2: Loops B/C/D & AABAS Accessibility Upgrades » Document List

This project will rehabilitate the 5,000 linear feet of campground roads in Loops B, C, and D, and 120 campsites, making 10 fully accessible. This project will be one of several to rehabilitate and repair the badly deteriorated campgrounds that are located outside of Yosemite Valley and away from the Merced River corridor. Compliance for Phase I (Loops A & E) can be found in PEPC 89693.

CONSTRUCTION TIMING: Tree removal is planned to occur in Fall of 2021. Construction is anticipated to occur from June 2022 to November 2022, which would close the campground to visitor use entirely for that year. The park had initially planned to sequence the project activities to allow for the campground to remain open during construction, due to the funding availability being cyclical at that time. However, the park is now able to construct Phase I and Phase II activities during the same year. Sequencing the construction by each loop would degrade the visitor experience in loops proximal to active construction and could pose additional safety issues and operational complexities. Consolidating construction to one summer closure (versus subsequent loop closures each summer) was selected as the option that would minimize perturbations to visitor experience in the long term, would maximize safety and operational efficiency, and would best fit project funding availability.

DETAILED PROJECT DESCRIPTION: Phase II work includes the pulverizing and repaving of the existing paved loop roads, repair and corrections to drainage throughout B, C, and D camping loops, restoration of camping sites, and native revegetation of disturbed areas within the campgrounds, as well as accessibility upgrades.

Roadway Restoration and Drainage Control:
Phase II includes repaving approximately 5,000 linear feet of existing campground roads in loops B, C, and D to correct failing pavement and drainage problems, as well as improve visitor experience. The project would correct drainage problems by installing 5 culverts and constructing 911 linear feet of unpaved ditches to correct design flaws. New culverts would be installed for ditches crossing the parking areas and where new culverts are needed to convey water from one side of the road to the other. Areas of severe erosion will be regraded and revegetated to restore natural conditions. Surface water flow will be controlled through the use of drainage ditches and culverts. Riprap will be installed as energy dissipaters at culvert entrances and exits, as well as in steeper sections of the drainage ditches. The road will be regraded to flow towards the uphill side, preventing storm water run-off from crossing the road and creating new erosion. Surface water flow will be controlled by eliminating or formalizing channels that have formed over the years, and by minimizing areas of concentrated flow. Many of the channels that have formed are a result of poor drainage design and water being allowed to flow across the roads, as road failures have created localized low points concentrating water into a single point source.

The campground loops and campground parking spaces will be repaved with asphalt. Several road curves will need to be modified to accommodate the wider turning radii required by today's RVs to prevent the vehicles from driving off the road and damaging road shoulders and drainage ditches, as well as to accommodate emergency vehicle access and snow removal equipment. To accomplish this, six curves would be widened involving 600 linear feet of roadway to accommodate a 30-foot RV pulling a trailer. Any RV longer than 30 feet pulling a trailer would be required to park their trailer along the main campground road. This design would also account for a fire truck and snow removal equipment; the horizontal road alignment would not be affected. Road re-paving would involve pulverizing the existing asphalt pavement, mixing it into the existing road base, and laying new asphalt to restore a smooth driving surface.

When the roads were originally built, tree stumps were paved over, causing the road to fail in several areas as the stumps decomposed; these stumps and roots will be removed. Stump removal will be limited to those impacting the road, and removals necessary to grade campsite pads and parking areas.

Resource Protection:
Some campsites in Loops B, C, and D encroach on sensitive resources, as campsites in Loop B are located within an archeological site and encroach on sensitive archeological resources and a few sites in Loops B and C encroach on sensitive meadow vegetation. The park proposes to remove 9 campsites out of these areas. When sites are removed the picnic table, fire ring, and bear locker would be removed. The paved parking spur would be removed as well, and the area would undergo revegetation with native plants. Of the sites removed for resource protection, all 9 would be replaced by expanding existing single sites into double occupancy sites, based on which existing sites have sufficient space to accommodate the extra living and parking space required. Overall, the campground capacity will not be significantly impacted, as 93 of 102 sites would remain available for camping. The number of campers the campground can accommodate would remain unchanged.
Presently, the Loop C entrance road traverses through an archeological site. During the proposed work to re-pave the road, the park proposes to elevate a 100-foot section of the road, so that the installation of the culvert will have no impacts to the archeological resources in the area. The road would be elevated 36 inches (at the highest point) above the current grade to accommodate the 24-inch culvert, which would be installed with no vertical ground disturbance. The existing road will be pulverized in place, and fill material brought it to avoid subgrade disturbance of any archeological features.
Barriers would be placed in vulnerable areas of the campground loops to discourage visitors from trampling sensitive meadow vegetation. The barriers would be made of native logs from tree removal activities. Logs will be placed on top of native ground and would require minimum ground disturbance. Signs would be placed along the barriers to educate visitors on the natural history of the area and on the value of meadow ecosystems. Signs would be made of metal, mounted on pressure treated posts. Pressure-treated wooden barrier posts and boulders will be installed to limit-off road vehicle travel and limit vehicle parking to appropriate areas, as compatible with original campground design.

Campsite Restoration and Improvement:
The number of campsites will remain similar to what currently exists in campground loops B, C, and D; however, a few campsites would be removed, and a few campsites would be made into double sites. The project would improve and establish campsite definition at the 93 campsites in loops B, C, and D. The park would re-grade campsites, improve walkways by formalizing existing social trails, replace campground furnishings, perform re-vegetation of bare areas, and replace campsite number signage in-kind in the same location, or an alternate location that would minimize the likelihood of damage. Where possible, the park would reduce individual campsite footprints and site limits established using vegetation, as well as natural barriers such as logs and rocks/boulders (as sites have sprawled and lost their individual definition over time). The park would install pressure-treated wood bollards and use asphalt paving to define parking areas for each campsite. Each campsite currently includes a minimum of one parking space. Two parking spaces per site is preferred and will be accommodated where feasible. The park proposes to formalize parking that would accommodate two cars at 27 campsites.

The park would construct a 5-car overflow parking area off the main campground road. The park would also construct 2 small overflow parking areas along loop C (each would accommodate 4 cars). Grading will extend up to 10 feet on all sides of each parking area. Each single campsite has a capacity of 6 people, and each double campsite has a capacity of 12 people. At campsite capacity, it is very unlikely that all campers arrive in a single vehicle, which is why is overflow parking areas are needed.

Camping pads and other areas with severe erosion will be regraded to restore and better define sites. It is anticipated that some grading activity will need to occur at each campsite, based on the existing eroded nature of the campground. Tent pads will be graded to establish a relatively flat camping area (graded to <2% grade). The park would regrade 93 sites to create level areas (less than 2% slope) for tent pads and camping space. These grading activities would involve cutting and filling the existing grade to level the campsite pads, as well as short dry rock stack retaining walls where pad grades cannot be reasonably tied into existing grades. The park would construct dry rock stack retaining walls with locally sourced boulders.

The park would also add paved walkways leading from the campground road to the comfort stations, and around the exterior of the comfort stations as part of the accessibility upgrades, which requires a hardened, durable surface. All walkways will be 4-inch thick concrete and 5 feet wide. Vertical depth of disturbance will be 1 foot below grade, with tie-in grading approximately 5 feet from each side. One 5-foot wide non-accessible path to the southern comfort station in Loop D will be constructed out of native soil and will include wooden steps to give an established path to the comfort station. Vertical depth of disturbance will be 1 foot below grade, with tie-in grading approximately 5 feet from each side. Each spigot would be retrofitted with a 6-foot by 6-foot, 4-inch thick concrete pad and have drain gravel added on the downslope side. Vertical depth of disturbance will be 1', with tie-in grading extending 5' on all sides. In Loop D, a new spigot would be added to restore the water spigot.

An earthen trail is also proposed in Loop D, that would lead from the loop road to the west to the southernmost comfort station. The trail would be 5 feet wide and made of compacted native soil.

The project would replace campground furnishings (bear boxes, fire pits, tables). Fire pits would be replaced within 20 feet of their existing location, on grade, requiring no additional soil disturbance. New fire pits would be of the same scale, setting, and general design as the existing fire pits.

The park would revegetate bare soil with native plants where pedestrian and vehicles have trampled existing vegetation or resulted in inappropriate areas of bare ground; temporary caging/fencing and/or signs may be required to allow plants to re-establish. The park proposes to protect existing sensitive meadow vegetation in close proximity to the campground by the adding educational signage, that would include messaging to stay out of the meadow.

The park would add 4 dumpster pads along the main campground access road near loops A, B, and E. Currently at Crane Flat Campground, dumpsters are placed along the side of the main road at Crane Flat Campground. At the end of the season, all the dumpsters get moved to the end of the road near Loop E and get replaced along the main road when the campground opens. The placing of the dumpsters is not always in the same place, causing loss of vegetation along the road. Creating paved dumpster pads keeps the dumpsters in the same location and minimizes vegetative impacts along the road. The number of dumpsters will remain the same, as this is sufficient for the campground's needs.

Accessibility Improvements:
The park proposes to upgrade 10 campsites in total throughout the campground to meet Architectural Barriers Act Accessibility Standards (AABAS) standards; this number includes a percentage of each of the different types of campsites available at Crane Flat Campground. Crane Flat accommodates both RV with tent and tent-only camping, including 77 RV with tent, and 89 tent only sites. Following ABAAS standards based on the number of each type of campsite, the minimum number of camping units with mobility features required is 5 RV with tent and 5 tent only, bring the total number of accessible sites to 10. Although during Phase I consultation we anticipated that all accessibility upgrades would be made in loops B, C, and D, based on the existing grades, with further investigation we have determined that 3 sites in loop E can support accessible campsites. In addition, a recent topography study of campsites in loop B, C, and D supports the ability for 18 campsites in these loops to be made accessible, although at this point the park has not determined exactly which eight sites will be selected for accessibility improvements. Sites will be selected during final design and will be spread throughout the campground as much as possible. Terrain and the amount of grading are criteria that will be considered to select the sites. Flatter sites are more favorable because less grading is required, which decreases the amount of disturbance. Steeper sites may require stepped features, which are not accessible. Upgrades would include grading a larger area for the tent pad and living space (a typical campsite ranges from 200 SF of living area to 500 SF, whereas accessible campsite can be as large as 1,000 SF for a single accessible site, and 1,200 SF for a double accessible site), provision of accessible parking (approximately 24 feet wide by 21 feet long), and the installation of accessible bear boxes, picnic tables, and double ringed fire pits. Accessible campsites allow a minimum of 48 inches of level clear space in front of the bear box, 48 inches around the fir pit, 36 inches around the picnic table, and 36 inches around the tent pad. As long as minimum clear space is maintained around each feature, the clear space areas may overlap. Additionally, each accessible campsite will be graded to a 2% minimum and 3% maximum grade.

Furthermore, while not initially proposed in the phase I consultation, the park also proposes here (in phase II) to make an AABAS accessible path to each comfort station by constructing concrete paths to each comfort station from the loop road, as well as concrete paths around each comfort station and to the faucets. Each accessible concrete path will be 60 inches wide with a compacted 12-inch shoulder, and will require a vertical disturbance of 18 inches and a horizontal disturbance up to 36 inches off of each side for tie-in grading.