Editor's Note: We keep receiving more excellent news from participants who were able to achieve their goals & who plan to work on ongoing projects. The Taber Irrigation District has been working on 3 projects with 2 fully completed - and one to be completed over the next month. But before we get into it, it's worth remembering that if you look out onto the landscape, you might not know what is being done - or why. It might look like either: "Not much" or "Big, bad equipment" to the untrained eye.
But how do we REHABILITATE our watershed? If that question doesn't interest you, how about HOW DO WE MITIGATE FLOOD AND DROUGHT? The answer is WETLANDS and NATIVE GRASSLANDS. Here's a link to a video on wetlands and the flood problem just downstream from the Oldman a couple years ago (your memory is not that bad, is it?!) https://vimeo.com/153843975 Here's another link to an interview done with the filmmaker: http://oldmanwatershed.ca/blog-posts/2016/2/21/interview-with-rick-searle-on-wetlands-matter-documentary
You can find out more about who's doing what and why (the people who are moving from talk to action) at the upcoming #SAWC17 awards ceremony. IT'S FREE! PLEASE JOIN US!
The #SAWC17 awards ceremony will be held on November 17, 2017 (09:45 AM) at Southern Alberta Ethnic Association to celebrate those who completed their pledged actions and to hear from their success stories.
For free registration to the event, click the following link: http://sawc17.eventbrite.com
Taber Irrigation District's, District Manager, Christopher Gallagher gave us some insight on what these projects are about - and explains what you are seeing out there.
Project 1: Constructed Wetland
The Taber Lake Lateral Constructed Wetland, located approximately 3 km east of the Town of Taber, was created from a 2 Ha backwater zone between the downstream toe of the east dam of Taber Lake Reservoir and the Taber Lake Lateral. Nearby grazing cattle accessed this area that included a mix of wet ponded areas, high grasses areas and scrubland. The area, not well-suited for grazing or running water, was identified by Native Plant Solutions (NPS - the technical arm of Ducks Unlimited), as having good potential for development of a wetland.
Taber Lake Lateral Looking Upstream (North) from SE Corner of Future Wetland
Funding from Alberta’s Watershed Resiliency and Restoration Program (WRRP), which also funded the NPS study, was used to construct a containment berm along the east side, grade the site, install level control and inlet/outlet structures, and install fencing to exclude the cattle. The wet and variable soil conditions made construction a challenge, but good site management by NPS’s Lyal Egilson, and a capable crew provided by George Miller Excavating (GMX) ensured that grades were close to those specified in the design.
Wetland Bed Grading, Looking South
TID designed and installed a duckbill weir to stabilize water levels in the pool serving the wetland inlet structure. Taber Lake Lateral serves a number of irrigated parcels, and also conveys flows to help supply Fincastle Reservoir downstream. Flows in Taber Lake Lateral are adjusted by the operator based on the downstream demand. The long weir length of the duckbill design allows the pool level to remain stable as flows to Taber Lake Lateral are adjusted, ensuring flows into the wetland through the inlet check structure are maintained.
Duckbill Weir Looking Upstream
Pool Looking South Showing Duckbill Weir (Left) and Inlet Structure to Wetland (Top)
The outlet structure controls the level in the wetland.
Outlet Structure Back into Taber Lake Lateral Looking NW
The process of establishing cattails in this area has been a challenge, but Melissa Mushanski with Native Plant Solutions completed seeding in early June and has been advising TID staff on managing levels, including keeping low areas pumped out. This first year has involved long periods of dewatering to encourage germination.
Pumps (background) Were Used to Maximize Seed-Soil Contact During Dewatering”
The effort is paying off as new plants emerge and existing plants thrive. Plots were selected by NPS to evaluate the progress objectively.
Pin Flags for Quadrat to Monitor Growth Progress of Cattail
TID is encouraged by the steady progress of wetland establishment and looks forward to mature infill.
Taber Lake Lateral Wetland Looking South from Inlet
Project 2: Drain Water Characterization & Synoptic Study
EXO 2 Sonde (www.ysi.com)
With cost-share funding through the Growing Forward 2 – Irrigation Conveyance Works Management Program, TID has partnered with Alberta Agriculture and Forestry (AAF) to characterize the water we receive into our open water systems through surface and subsurface drainage systems. Regular water sampling has been conducted in bottles for laboratory analysis, while simultaneously testing with a mobile multiparameter probe called a Sonde. The Sonde has an internal logger and has also been deployed in our Taber Lake Lateral to gain insight on the changes in water quality parameters over time. The project included a synoptic study completed in early June, in which samples were taken from the canal as it flowed and from each drain inlet where drainage entered the canal.
Drain Inlet Sampled in 2017
Results from one reach are already assisting in the design of mitigation for an adjacent parcel that drains to our Taber Lake Lateral. Additionally, TID is evaluating the effectiveness of a denitrification bioreactor that was installed to mitigate for tile drain discharge. The preliminary results are promising. It seems that the hemp straw medium that was used is having a significant beneficial effect in reducing the concentrations of key parameters such as nutrients and E.coli.
Hemp Straw as Carbon Medium for Denitrification Bioreactor
Project 3: Lateral 18 Taber Canal – Naturalized Drainage, Retention and Treatment System
The Lateral 18 Taber Canal rehabilitation involved installation of a buried pipeline for irrigation deliveries, and repurposing of the 4 km downstream reach for drainage. Rather than just leaving the canal as a drain ditch for conveyance, TID thought this could be developed as a linear storm water pond. TID designed a series of permeable checks and weirs for water retention during high flow events, followed by slow release. This reduces channel erosion and allows settling of sediment from the adjacent land base.
Permeable Check Structure – Gaps in the Boards Allow Slow Release
Not stopping at hydraulic retention, TID has designed infiltration systems with a hemp straw core that will act as a bioreactor to enhance the effectiveness of the infilling vegetation. This will also allow denitrification and other bioremediation outside the growing season. The remaining structures are being installed in the next few months as TID maintenance crews are available.
The Oldman Watershed Council is a not-for-profit, registered charity. Our Board consists of a large group of sector representatives - 23 voices united together behind policies, research, education, and projects for the betterment of watershed management and health. We welcome all efforts made to make a difference in our watershed. Volunteer. Donate. Make a Change.
