b.US15-0307A_Trip_Report.pdf

32 N MAIN STREET PO BOX 235 PAYETTE, IDAHO 83661 208-642-3304 208-642-2159 FAX

MEETING REPORT

Meeting Date: March 31, 2015

Meeting Location: Hells Canyon Boat Launch – Hells Canyon NRA, Wallowa-Whitman NF

Project: Scoping for repair of the boat ramp and associated facilities

Project No.: AG-04M3-C-15-0001 Prepared By: Doug Argo, Holladay Engineering

Attendees:

Brett Yaw, PE USFS Development Engineer Andrea Stanbro USFS, Contracting Officer Howard Wells, PE BergerABAM Travis Foster, PLS WHPacific, Inc.

Doug Argo, PE Holladay Engineering

PROJECT DESCRIPTION / NEED:

The Hells Canyon Visitor Center and Boat Ramp facility includes a boat ramp, ramp access roadway, vehicle and trailer parking area, floating boat dock on a trolley system to accommodate the dramatic water fluctuations within the canyon, and a raft launch facility. The boat ramp and the boat dock have been damaged recently and are the focus of this scoping project.

The Hells Canyon Boat Ramp was rebuilt in the early 1990’s. The boat ramp consists of a cast-in-place upper ramp with pre-cast panels comprising the lower ramp. The plans provided by the

USFS indicate that a steel rail system was used to align the precast panels during installation, and crushed rock was placed between the rails to support the panels. A concrete apron for raft launching was constructed along the river side of the boat ramp. The ramp is approximately

80 feet long and 24 feet wide, including the 10-foot wide raft apron. Gabions were placed at the end of the ramp to protect from erosion, and riprap was placed along the river side of the ramp to protect from erosion. Reports from boaters and USFS personnel indicate that there presently is a drop-off at the end of the ramp.

The dock and trolley system were installed in 1985. The dock assembly floated and moved up and down with changes in the water level. Movement of the dock was facilitated by the trolley and counter-weight system. Access to the dock was provided via a metal stairway on the upstream side of the dock assembly. The dock system was damaged in a flood on Hells Canyon

Creek in 2010. This creek comes through the Visitor Center/Boat Ramp complex and outlets between the dock and the boat ramp. The flood damaged the trolley system and other site improvements. The dock was removed by USFS personnel.

HOLLADAY ENGINEERING COMPANY

This project will evaluate the damage to both the ramp and the dock and provide recommendations for repairs.

SITE MEETING MINUTES

A field visit was conducted on March 31, 2015. Brett Yaw, USFS, indicated that river flow was around 10,000 cfs on this day, and this was near the expected low flow level for the spring season.

The following items were identified and discussed during the field visit:

1. Dock Site

a. Flood on Hells Canyon Creek overflowed its banks and was flowing down adjacent to the dock. USFS crews rerouted the creek back to its channel but the dock had already been damaged.

b. Upper portion of trolley system including rails and counterweight and trolley may be undamaged (photos 1 and 2). Lower portion near the water line has some damaged members and apparent broken joints (photo 3)

c. Bottom end of the rail system below the water level appears to be buried by sediment from the flood (photo 4).

d. The access stairway along the upstream side of the dock system is poorly supported in some areas. Some of the stair treads are also damaged in the lower portion of the stairway (photo 5).

e. Divers are to review underwater damage to trolley and rail system on a future visit.

f. Engineers are to evaluate the above water elements during the same future visit.

g. Surveyors to locate dock system elements during topographic survey.

h. Project will provide options for repair and/or replacement of the dock system.

2. Ramp Access Road

a. We reviewed the access road which goes from the small parking area above the ramp down to the boat ramp. Boat trailers are hitting the gabion wall located on the uphill side of the road. Several gabions are broken (photos 6 and 7).

b. The road should be widened to provide easier access for the boat trailers.

c. Surveyors will pick up sufficient topographic data to accurately portray the present configuration of the parking lot, access road, and gabion wall.

3. Boat Ramp

a. The drop-off at the end of the ramp was plainly visible from the bank. We could not tell whether the end of the ramp was undermined (photo 8).

b. Construction photos provided by the USFS showed gabions being placed at the end of the ramp and riprap placed on the river side of the ramp.

c. Both the riprap and the gabions appeared to be completely washed away (photo 9).

d. The edge of the ramp adjacent the river is undermined (photo 10).

e. Divers will review underwater conditions.

4. Next Site Visit

a. Both WHPacific and BergerABAM intend to be on site April 14, 2015 to complete their respective site evaluation tasks.

b. Site safety plans are required for both crews. BergerABAM and WHPacific both indicated that these plans would be forwarded well in advance of the site visit. Both indicated that site conditions appeared to be within expected risk limits, and so long as site conditions did not change significantly, their crews should be able to accomplish the diving and bathymetric survey as planned.

SITE PHOTOGRAPHS

Photo 1: Upper portion of dock access assembly Photo 2: Upper portion of dock trolley system

Photo 4: Burial of lower portion of dock rail system. Photo 3: Damage to lower portion of dock rail system.

Photo 6: Gabion damage, ramp access road.

Photo 7: Gabion damage, ramp access road.

Photo 5: Damage to stair treads.

Photo 10: Undermining of river side of boat ramp

Photo 9: Edge of boat ramp, missing riprap.

Photo 8: End of boat ramp.