Our Work in the S’amunu/Somenos Watershed

Once salmon freely migrated from Cowichan Bay to the many creeks around Somenos Lake, completing their natural life cycle and beginning a new generation of fish for the community. Today, the pollution of our waterways has made that all but impossible. GreenStreams has a vision that will restore the S'amunu waterways to health and bring the salmon back to our rivers.

The GreenStreams goal is to work in partnership with local residents to restore the S’amunu/Somenos Watershed from the mountains to the sea, beginning with the stream corridors on Swuq’us (Mt Prevost) and Richards Mountain, and ending at the Cowichan River. This includes Richards, Averill, Bings and Somenos Creeks, their tributaries, and Somenos Lake and Marsh.

GreenStreams recognizes that landowners who live along these waterways are valuable partners in restoring them to health, and managing them responsibly for future generations. We collaborate with these residents by helping them evaluate their property, understand how their activities affect the watershed, and identify solutions that work for them. By exchanging knowledge and collaboratively solving problems, GreenStreams empowers residents to become stewards of the watershed, preserving the waterways and the plants and animals that depend on them.

Other community members can contribute their time and knowledge to our project as volunteers through the Community Stewardship Program. We rely on Community Stewardship volunteers to help us manage invasive plants, add to riparian planting, restore in-stream areas, and monitor water quality according to our 5-Year S'amanu Watershed Recovery Plan.

Working together, we can reverse the contamination of our local waterways and restore the S'amunu watershed for future generations.

Our Projects

Riparian Restoration

The three main tributaries flowing into Somenos Lake - Averill Creek, Richards Creek, and Bings/Menzies Creek, all support populations of spawning salmon, as well as the BC blue-listed Coastal Cutthroat Trout. Each creek drains creeksheds that contain urban, residential, industrial, agricultural, and forestry lands. SMWS staff, along with a consulting biologist, completed Level 1 & 2 Watershed Assessments for each tributary in 2020 and 2021 and, from the data collected, have prepared a Restoration Priority Plan for all three creeks. The plan involves riparian area improvements (planting and invasive plant removal) along with some in-stream works. The plan also identifies projects needing to be undertaken by the Municipality to improve fish access or improve water quality. We thank the Pacific Salmon Foundation for funding the 2022 creek assessments and we would also like to thank our friends at the Cowichan Green Community for giving us the space to store, and helping us maintain, our restoration plant inventory.

Water Quality Monitoring

Historically, Somenos Lake has provided critical year-round habitat for salmonids within the Somenos Basin. Currently, however, it only provides suitable habitat during the colder and wetter months of the year. This is due to high temperatures in the upper water column and anoxic conditions (low levels of dissolved oxygen) in the lower water column during the summer. Poor water quality has led to prolific cyanobacteria (blue-green algae) blooms during the summer that create an anoxic environment unsuitable for salmonids. Water quality monitoring has been ongoing in Somenos Lake since spring 2014, weekly during the summertime and monthly during the winter. Every year, volunteers measure water temperature, dissolved oxygen, pH, dissolved solids, specific conductivity, nutrients, water clarity and lake levels.

 To complement the data collected by volunteers, permanent data loggers were installed in the deepest part of the lake, measuring water temperature hourly at the surface, at mid-depth and at the bottom. This project provides crucial information that helps us track water quality fluctuations throughout the year and their effects on the ecological functions of the Somenos Basin. This, in turn, helps us identify, develop, and execute studies and management plans that will improve these conditions. This citizen science water quality monitoring program also help us monitor the long-term effectiveness of ecological restoration efforts delivered throughout the S’amunu watershed. Thank you to the Pacific Salmon Foundation, Municipality of North Cowichan and in-kind support from the Cowichan Watershed Board, Cowichan Valley Regional District. Without the support of all of you we would not be able to continue our research. Special thank you to all the volunteers that have participated in this project, we cannot do it without you.

You can find a collection of water quality reports in our library.

Fish monitoring

Despite its historic reputation as the greatest salmon nursery on southern Vancouver Island the S’amunu Watershed has not been closely studied over the years leaving a lack of data about populations, spawning numbers, or species. There have been some studies, particularly of the upper Richards Creekshed Coho population, but apart from this data, recorded information is limited. The SMWS is exploring the use of smolt traps, minnow traps and a Didson (sonar) camera to improve our ability to collect accurate numbers and to identify the species, ages, and numbers, and how each utilizes the Somenos system. We are also embarking on collecting an oral history of salmon use of the S’amunu Watershed and to learn if spawning salmon made it past the waterfall barriers on Bings and Averill Creeks in past years.

Salmon Watch Program

The Salmon Watch Program is a Citizen Science exercise where we enlist the community to watch for spawning salmon. Since we have a concern that the poor water quality of Somenos Creek might be delaying spawning salmon from reaching their S’amunu Watershed spawning grounds, we are using volunteer monitors to watch the spawning sites to provide reports of arrival times, locations, numbers and to capture some video if possible. These numbers will help us determine the success of our efforts to improve the water quality to the point when salmon can access the Somenos system as early as possible.

Bings, including Menzies Creek stem

Bings Creek (sometimes called Holmes Creek) and it’s lesser tributary, Menzies Creek, were assessed in 2020 along with a property owner contact and survey exercise. Using the assessment results, staff launched our restoration efforts in 2021 with a small project on Bings Creek close to the Trans-Canada Highway, where we increased salmon spawning habitat by adding gravel and large rocks to rehabilitate and renew some old spawning areas. A couple of salmon were seen shortly after scoping out the new site. This project was completed with funding from the Ministry of Highways and the Municipality of North Cowichan. We have plans to return in 2022 to restore one more spawning site in the same area. Our goal is to eventually create a wetland complex west of the Trans-Canada Highway (behind the current RCMP detachment building on Canada Avenue) to help mitigate the poor water quality caused by storm sewers flushing roads into the creek, and at the same time, creating some badly needed salmon spawning and rearing habitat in the area.

Averill Creek

Averill Creek was assessed in the summer of 2021 along with a property owner contact and survey exercise. SMWS staff also assisted provincial personnel in a flow monitoring exercise which will likely continue in 2022. We recently started a small restoration project on Averill Creek funded by TD/Canada Trust Friends of the Environment Foundation and the SMWS. We will return there in late summer to complete the work when salmon are not in the stream. We will continue to work with Cowichan Tribes and the Provincial governemnt conducting flow monitoring studies on the creek.

Richards Creek

Richards Creek was assessed along with a property owner contact and survey exercise in the summer of 2021. Being that Richards Creek is vastly different ecologically than Bings and Averill Creeks due to the terrain it passes through is mostly flat and agricultural and past dredging has resulted in more of a drainage ditch than a functioning stream in the lower reaches, staff are undertaking a neighbourhood initiative to learn more about the needs and wants of Richards Creek drainage residents before embarking on any restoration activities in the Richards creekshed.

Somenos Lake

Our work in Somenos Lake is currently limited to water quality testing in the centre of the lake and at each tributary entrance into the lake. We test weekly from the spring until the late fall rains, and then monthly until spring returns. We also conduct invasive plant surveys along the lakeshore on a regular basis. The Drinkwater Dock and fishing float, from where the SS Somenos, our electric survey boat, launches, as well as the information kiosk were built by the SMWS and gifted to the Municipality of North Cowichan. Both SMWS staff and volunteers maintain the area on a regular basis.

Somenos Creek 

Our primary work on Somenos Creek involves dealing with Parrot’s Feather (PF), an invasive aquatic plant that, in summer, covers more than 85% of Somenos Creek’s 3km length before it meets the Cowichan River. PF was first introduced to Somenos Creek in 2014, and over the past 8 years, has creating dense mats of floating vegetation that can obstruct the creek’s natural flow. We are currently researching the impact of Parrot’s Feather on salmonid species ability to travel upstream to Somenos Lake and its tributaries where spawning occurs. This research includes monthly surveys during the PF growth season to monitor the spread and behaviour of the plant combined with inquiries on the effect that parrot’s feather has on water quality pertaining to fish migration. Our long-term strategy is to restore the riparian vegetation cover to recover ecological functions in the riparian area that will control the spread of PF, a shade intolerant plant. For a more immediate solution, we are looking into the acquisition of an aquatic weed harvesting machine to mechanically clear paths through the Parrots Feather mats for water quality and fish passage improvements. To learn more about Parrot’s Feather visit our library page or check out this educational poster created by one of our 2020 summer staff. 

The SMWS’s main wildlife viewing infrastructure, apart from the Drinkwater Dock, is at the Somenos Marsh Open Air Classroom. This small property, which was once a paved commercial site with a large building, now has trees, elevated boardwalks, gravel trails, a viewing tower and other amenities and is maintained entirely by SMWS volunteers. Volunteer work parties are regularly held year-round to help maintain the facilities. This work could include, removal of invasive species, cleaning up homeless camps, moving rocks back to the path edge, and a lot of grass and brush clipping during the height of summer. We also have some interesting projects ahead including managing the small field that borders the south leg of the boardwalk and the possible extension of Derricks Way / For the Birds boardwalk and platform closer to the field for better waterfowl viewing in winter when the field is flooded.

The swallow nest box program at Somenos Marsh has existed since the early 1970’s when nest boxes were installed by Cowichan Valley Naturalists Society member, John Comber. Later in the 1990’s, long-time birder and naturalist, Derrick Marven, installed many more boxes on fence post extensions throughout the marsh. The nest boxes are frequented in spring by many breeding Tree Swallows who benefit from this important support. Invasive species such as House Sparrows also like to make their nests in these boxes if they can get in. Project Nest Box’s purpose is to collect data about the species that use the nest boxes and submit the data to a national bird data tracking program.  Nest boxes are monitored and cleaned in the fall and data is collected on which species has been nesting in each box. The project engages students in building, maintaining, and monitoring nesting boxes for Somenos Marsh native cavity nesters.

Stormwater Treatment Wetlands

The SMWS proposed in 2013 to develop the Conservation Area’s Beverly Street property, once slated for a new police station location, into a wetland to support increased biodiversity for native plants and animals and provide an ecological service by pollution remediation of urban stormwater runoff before it passes under the dike into the Somenos fish-bearing system. The project began in 2015 and, once the machine work was completed, volunteers moved in under SMWS supervision to plant the disturbed area. In the summer of 2021, the final phase of the Beverly Street Wetland project was undertaken by North Cowichan, when further pond excavation and shaping of the land was performed, along with blocking the main ditch that ran along the easternmost border of the wetland. The SMWS followed the completion of the earthworks with volunteers primarily comprised of an ecology class from Cowichan Secondary School, who planted the newly contoured area with about 700 trees and shrubs. The SMWS is currently in discussions with the Municipality of North Cowichan to develop a site-monitoring program. This program will likely include inventory and survival monitoring of the newly planted flora, along with water quality sampling and soil contaminant sampling at the inflow and outflow points of the wetland to ensure efficacy of the pollutant-removal powers of the constructed wetland.

Invasive Species Management

S’amunu is home to numerous invasive plants and wildlife. Top of the list for the SMWS is the Parrot’s Feather aquatic weed covering a significant area of Somenos Creek. The next problem plant on our invasive plant hit list is Yellow Flag Iris which has become a significant issue due to late-season draining fields. We also manage Himalayan Blackberry, despite its delicious berries, as it is a prolific spreader and out competes many native plants. Then we have all the other plants and trees including non-native English Hawthorns, Purple Loosestrife, Scotch Broom, and others. In the animal world we have a serious American Bullfrog issue that we are hoping will settle itself as the population finds its place in the ecosystem as management is not in our plans presently. The same goes for the Pumpkinseed fish (sunfish) which are very happy in the unhealthy waters of Somenos Lake and in numbers that are not manageable. The good news is that predators have taken a liking to bullfrogs.

Completed projects

Having 35 years of history under our belts we have completed many important projects. These include construction of elevated boardwalks that allow access to flooded areas during winter, a viewing tower, a book - Somenos …the Grandfathers spoke to me, videos and many restoration projects. Our most recent 3-year restoration project was our Clean Water Action Project where we mapped and supported Somenos Lake properties that needed riparian planting and invasive weed management.