Explosives Creek flows into Tunstall Bay on the west side of Bowen Island. Tunstall Beach is one of the most popular beaches for the Bowen community, and the Tunstall Bay Community Association Recreation Centre is just above the mouth of Explosives Creek.

Historically, Explosives Creek was a productive habitat for spawning salmon but culvert installation about 40 years ago made the upper creek inaccessible from the ocean. Bowen Island Fish & Wildlife Club (BIFWC) volunteers, under the supervision of Fisheries & Oceans Canada, have been releasing chum and coho fry into Explosives Creek since climbing pools were constructed up to the culverts in 2010. In 2014, the BIFWC organized a Pacific Salmon Foundation funded project to create a chum spawning bed, open a self-scouring channel across Tunstall Beach, and repair beach hillside erosion.

The 5 minute video on our Home page gives an excellent overview, and the Explosives Creek – Tunstall Beach Habitat Rehabilitation Project PDF above provides more detail.

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Explosives Creek – Tunstall Beach Habitat Rehabilitation Project 2013/14

Explosives Creek – Tunstall Beach Habitat Rehabilitation Project

INTRODUCTION

Background

In 2010 the Bowen Island Fish & Wildlife Club (BIFWC), supported by the Department of Fisheries & Oceans Canada (DFO) and with funding provided by the Pacific Salmon Foundation (PSF), built climbing pools from the mouth of Explosives Creek to several large raised culverts to allow access for coho to about 500 metres of prime spawning habitat. Since then the BIFWC has been releasing coho and chum fry raised in the Terminal Creek Salmon Hatchery into Explosives Creek.

It is important to have good water flow between Explosives Creek and Tunstall Bay so that the coho fry can depart into the ocean in the spring and returning spawners can get back into the creek in the fall. Most years a combination of undependable creek flows and winter storms creating high gravel berms on Tunstall Beach has blocked the connection between Explosives Creek and Tunstall Bay. In addition, winter storms have caused erosion of the foreshore bank below the tree-covered hillside, a valued habitat feature of the entire beach.

Purpose of the Explosives Creek – Tunstall Beach Habitat Rehabilitation Project

The BIFWC is coordinating the Explosives Creek – Tunstall Beach Habitat Rehabilitation Project. The project includes four components which will be completed over 2 days, Saturday, May 3rd, and Sunday, May 4th, 2014. J&E Backhoe is doing the excavator work, moving material and placing large boulders & logs, under the supervision and with technical support from Rob Bell–Irving, DFO’s local Community Advisor, and with the help of volunteers organized by the BIFWC.

Key Components of the Project

1. Shovel accumulated gravel out of the climbing pools.
2. Create a rearing pool and spawning bed between the base of the climbing pools and the beach.
3. Re-enforce the existing natural channel across the beach so that it is
   self-scouring and open during the spring and fall.
4. Repair bank erosion then replant and place fencing & signage to protect the hillside between the beach channel and the parking lot.

Funding and Volunteer In-Kind Contributions

Funding for this project has been provided by the Pacific Salmon Foundation (PSF) under their Community Salmon Program. PSF is an independent not-for-profit organization that works with the public which includes: volunteers, community groups, business, industry, academia and all five levels of government (Federal, First Nations, Provincial, Regional, and Municipal) to protect, conserve and rehabilitate Pacific salmonids and their habitat. The Community Salmon Program has been issuing grants since 1989, providing resources to enable the public to participate in DFO’s Salmon Enhancement Program and in volunteer-based watershed stewardship activities. PSF grant funding for any specific project must be matched or exceeded by volunteer in-kind contributions. The total value of this Explosives Creek – Tunstall Beach Habitat Rehabilitation Project is approximately $25,000.

Bowen Island Community Support

Tunstall Beach is one of the most heavily used beaches on Bowen Island.

The landowners above Tunstall Beach are the Tunstall Bay Community Association (TBCA) and Bowen Island Municipality (BIM). Both TBCA and BIM Mayor & Council have written letters supporting this habitat rehabilitation project. In addition to the public, there are several important users of Tunstall Beach; the Bowen Island Yacht Club (BIYC), which also sent a letter of support and has operated their Learn to Sail program at Tunstall for many years, and Bowen Island Kayaks, which uses Tunstall as an optional kayak launch site. Both organizations are supportive of this salmon habitat rehabilitation project.

REMOVING GRAVEL FROM THE EXPLOSIVES CREEK CLIMBING POOLS

The Explosives Creek climbing pools constructed in 2010 rise from the mouth of the creek to two culverts. Above the culverts is about 500 metres of prime coho spawning habitat. In order for coho to climb the pools, gravel must be removed annually.

BIFWC volunteers start the project by shoveling gravel from the top pools and work down.

In assembly-line fashion, Andre Chollat’s bucket is filled and passed along. To make the load easier for senior volunteers, holes have been drilled in the bottom of the plastic buckets to allow the water to drain out.

This view illustrates the assembly-line process of removing gravel from the climbing pools and piling the gravel at the bottom to be spread by an excavator. This gravel, and additional gravel that migrates from above the culverts during heavy rainfalls, creates an excellent spawning bed for chum salmon unable to climb up the pools.

After the gravel has been removed from the climbing pools, the increased water depth allows coho to jump from level to level then navigate through the culverts to the spawning habitat beyond.

CREATING THE REARING POOL AND SPAWNING BED

After some leveling by the excavator, gravel that is piled at the bottom of the climbing pools is spread and a small pool is created to allow coho to jump into the first pool. Several boulders had to be adjusted so that the water flow and levels were optimal. Note how shaded and well planted the new rearing pond and spawning area is; ideal for fish.

The excavator continued along the channel from the base of the Explosives Creek climbing pools to Tunstall Beach; leveling and placing gravel in the spawning bed. There was minimal disruption to the thick vegetation on both sides of the channel. During summer dry spells when the water in the beach channel is extremely low, coho fry and cutthroat trout can retreat to the spawning channel and rearing pond.

When the water from Explosives Creek enters onto the beach, it is important that the channel be built-up and strengthened with large boulders and logs to increase the water velocity during heavy rainfalls. This creates a self-scouring effect to keep the channel open. The excavator places boulders and logs along the natural channel bank. It is important to note that we did not try to construct a new channel, rather, the objective was to re-enforce the existing natural channel.

Looking from the mouth of Explosives Creek onto Tunstall Beach after the excavator has created the extensive spawning bed and re-enforced the entrance to the beach channel with boulders and logs. The plants and trees along the creek and beach channel have been carefully protected during all excavation and movement of material.

RE-ENFORCING THE NATURAL CHANNEL ACROSS TUNSTALL BEACH

This is the view looking from Tunstall Beach toward the mouth of Explosives Creek after the excavator has placed large boulders and driftwood logs to protect and maintain the entrance to the channel. During heavy rainfall the water flow from Explosives Creek becomes a torrent and at high, high tide in the winter the beach channel is full of ocean water.

The excavator continues to re-enforce the natural channel across the beach to Tunstall Bay. Boulders are carefully placed and a very large diameter log is placed upright into the gravel to stop other logs from washing up into the channel during high tides and storms.

Where necessary, large logs on Tunstall Beach were relocated by the excavator in the hope that they would prevent the build-up of gravel in the beach channel. Large stumps and firmly embedded logs were left undisturbed.

The completed re-enforcement of the channel across Tunstall Beach looking toward the mouth of Explosives Creek. This is in early May at low tide. At high, high tide in the winter the entire channel will be under 5 feet of water.

REPAIRING EROSION DAMAGE AND PROTECTING TUNSTALL BEACH HILLSIDE

One of the most important features of Tunstall Beach is the hillside and large cedar and alder trees providing stability and shade. Over the years the bank has eroded so it is very important to mitigate further erosion during winter tides and storms. The excavator placed boulders along the eroded bank and logs on the beach in front of the rocks to dissipate the force of waves.

The bank of the hillside was re-enforced with boulders and logs. Additional logs were placed above the boulders directly on the hillside to discourage people from storing kayaks, paddle boards, or putting derelict boats on the hillside. Activity on the hillside has a negative impact on plants, trees, and roots; all stabilizing factors which protect the hillside.

TUNSTALL BEACH RE-VISITED
CHANNEL REMEDIATION

In late November, 2014, a strong storm with high wind and waves during high tides caused significant damage to the Tunstall Beach channel and hillside bank rock wall. Bowen Island Fish & Wildlife Club (BIFWC) volunteers made the decision to hire J&E Backhoe and use the many large logs washed into the channel to redesign and strengthen the hillside bank.

There was significant damage and damming caused by logs and debris washed into the beach channel and settling in and above the pool toward the mouth of Explosives Creek.

During the storm many large logs were washed onto the beach and into the beach pool around the alder tree. The logs restricted the flow in the channel.

Debris, including surf boards, accumulated behind the logs toward the mouth of Explosives Creek.

The logs were removed from the beach channel by a wheeled backhoe while BIFWC volunteers cleaned up the debris which had been washed into the beach pool. The backhoe operator was careful to protect the alder tree leaning over the channel.

After the logs and debris were removed the water ran across Tunstall Beach to the ocean freely again.

We now recognize that nature’s winter storms and high tides will continually impact the channel across Tunstall Beach.

TUNSTALL BEACH RE-VISITED
HILLSIDE BANK REMEDIATION

As pointed out previously, the hillside above Tunstall Beach must be protected by mitigating erosion.

The rocks placed along the eroded bank became dislodged and collapsed because of strong storms during high tide. After researching better options, BIFWC volunteers came to the conclusion that the rock wall should be replaced with an irregular criss-cross of logs and rocks which will disperse the force of waves and reduce erosion.

Strong waves and high tides caused the rock wall protecting the eroded hillside bank to collapse. Note the boat that washed up onto the top of the rocks during the storm.

The rocks and washed up logs from the beach channel and pool were piled and criss-crossed haphazardly to build a redesigned protective barrier better able to mitigate the effects of winter storms.

CONTRIBUTING TO SALMON HABITAT REHABILITATION

This project would not have been possible without the energy and dedication of Bowen Island Fish & Wildlife Club volunteers, technical expertise and guidance from the Department of Fisheries & Oceans Canada, funding from the Pacific Salmon Foundation, and support from landowners, the Tunstall Bay Community Association and Bowen Island Municipality, and users such as the Bowen Island Yacht Club’s Learn To Sail Program and Bowen Island Sea Kayaking. We also thank Ed Weismiller and the employees from J&E Backhoe who assured work was done well and on time.

 

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Report written by: Tim Pardee, President
Bowen Island Fish and Wildlife Club
(604) 512-5245
https://bowenhatchery.org

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BIFWC wishes to thank
Cam Hayduk for photography
and Julia McCaig for print design.