Post on 16-Dec-2015
transcript
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WUQWATR Wascana Riparian Health
Assessment ProjectPhase 3 interim report August 2014
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Local non-profit source water protection agency
Implementing “Getting to the Source”, with 82 recommendations
Covers two watershed area, the Wascana and the Upper Qu’Appelle
Agriculture programming, invasive weed management and research
More info at www.wuqwatr.ca
Who is WUQWATR?
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WUQWATR Watersheds
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Lack of Riparian Health Assessment data in Wascana Watershed identified in 2008
Funding received for project design from Saskatchewan Watershed Authority in 2009/10
Field work was delayed by flood conditions in 2011
Wascana Riparian Health Assessment
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First field assessments in summer 2012 within City of Regina boundaries
Further design and field assessments took place in 2013 on Creek upstream of Regina
Third phase completed this summer downstream of Regina to the Qu’Appelle, and on portion of Cottonwood Creek
Wascana Riparian Health Assessment
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Phase 3 study area
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Smallest Saskatchewan watershed area, with highest population density
Highly modified environment. Major urban impact, and intensive cropping Saskatchewan State of the Watershed
Report condition ranking is “Impacted” Saskatchewan State of the Watershed
Report stressor ranks “High Intensity” Issues of flooding, invasives, nutrient
loading, high streamflow downstream of Regina.
Why Wascana Creek?
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Why Wascana Creek?
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What is the riparian area?
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Riparian Health Assessment uses observational data to measure indicators of riparian health
Some indicators involve identification of plant species composition and plant cover, and condition of plant life
Other indicators classify the physical condition of the bank such as structural composition and integrity
Why Riparian Health Assessment ?
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Allows for a better understanding of the condition of key ecological functions on the landscape
Data collected can be used as a baseline to monitor condition over time
Results can compare different management zones along a waterway
Results can inform management decisions made by landowners and managers
Can be used to identify project sites
Why Riparian Health Assessment ?
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Trap sediment Build and maintain streambanks Store flood water and energy Recharge of aquifers Filter and buffer water Reduce and dissipate stream energy Maintain biodiversity Create primary productivity
Key Ecological Functions of Riparian Areas
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Balances erosion with bank restoration – reduces effects of erosion by adding bank elsewhere
Increases stability and resilience Maintains or restores the profile of the
channel – and extends the width of riparian area through higher water table
Measures of Riparian Function-Streambank Protection and Development
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Utilizes two categories – Lotic for rivers and streams, lentic for lakes, sloughs, wetlands
Utilizes set questions – 12 for lotic system, 9 for lentic system
Utilizes visual observation and assigns point scores based on data
Overall Health score of 80% or greater rates “healthy”
Overall Health score of 60%-79% rates “healthy with problems”
Overall Health score of less than 60% rates “unhealthy”
Riparian Health Assessment -Method
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Scores 80 or higher
All riparian functions are being performed
High level of riparian condition
Demonstrates resiliency and stability
Health Assessment Ratings – “Healthy”
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Healthy Riparian Score
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Scores range from 60-79
Many riparian functions are being performed, but some clear signs of stress are apparent
The reach area many not be as capable of rebounding from floods and human activity
Health Assessment Ratings- Healthy with Problems
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“Healthy with Problems”
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Scores 0 -59
Most riparian functions are severely impaired or have been lost
Reach has lost most of its resiliency, stability is compromised
Health Assessment Ratings- “Unhealthy”
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“Unhealthy score”
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Preferred species have deep binding root mass
Most preferred species are native plants Good balance of trees –Willow, Manitoba
Maple, Elm, Green Ash, Hawthorn Shrubs Chokecherry, Saskatoon, Dogwood Forbs and grasses - Cattails, rushes, reed
grass, native grasses
Vegetative Cover – preferred species
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Invasive species out-compete preferred species
Often are exotic plants that lack local controls
Invasive plants impair riparian function Brome grass is pervasive throughout
watershed, replaces preferred grasses Disturbance plants grow where preferred
species have disappeared Sow thistle, burdock, dandelion
Vegetative cover – invasive and disturbance species
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Top 4 invasive plants species
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Top 4 invasive plant species – smooth brome
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Top 4 invasive plant species – scentless chamomile
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Top 4 invasive species – Absinthe
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Health rating – Wascana Creek Downstream
85%
15%
Health Rating Composition of Wascana Creek Downstream of the City of Regina
Unhealthy
Healthy with Problems
Healthy
Figure 2: This pie chart shows the health rating composition (healthy, unhealthy, and healthy with problems) of Wascana Creek flowing from the western city limits of the City of Regina to where Wascana Creek flows into the Qu'Appelle River.
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Average coverage score was 3 out of 6, which indicates significant areas of bare ground due to water
Lots of areas where flooding had washed out large areas, especially on outside meanders
Bare ground was more common further downstream
Results- Vegetative cover
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Vegetative Cover
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Average score for Wascana Creek was .04 out of 6
Prevalence of smooth brome
Also widespread scentless chamomile, thistle,
Absinth and locations with leafy spurge
Invasive species
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Overall average score on trees and shrubs is 8.8 out of 12
Trees are present and regenerating themselves
Presence of beaver browsing lowers score
Where are the beaver dams?
Presence of preferred trees and shrubs
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Average Wascana score of 2 out of 6
Indicates that overall only 35%-65% of the streambank is anchored with deep, binding root mass
Deep rooted vegetation
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Average scores are 4.5 out of 6 for human caused bare ground
Average score of 4.8 for human alteration
These are good indications about local management
Human caused bare ground and alteration by human activity
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Average Wascana score is .7 out of 6
This indicates that at least 30% of the site reach shows active lateral cutting from stream flow
Active lateral cutting
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Lateral cutting of banks
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Average Wascana score was 2.1 out of 9
This means that the stream cannot access its flood plain
This continues the cycle of incisement and slumping, until bank stability is achieved by erosion
Access to flood plain
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Access to flood plain
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Cottonwood Creek results
38%
13%
50%
Health Ratings of Cottonwood Creek
Unhealthy Healthy with Problems
Healthy
Figure 3: This pie chart shows the health rating composition (healthy, healthy with problems, and unhealthy) of Cotton -wood Creek from grid SK-730 to where it joins Wascana Creek.
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Physical structure of streambank has been clearly compromised by high peak flows, and intense rainfall events over the year
Problems with high flows are compounded by 60 meter drop in elevation
Highly erodible glacial till soils further downstream
Clay, loam, gravel, sand
Interpretation of results – physical structure
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Wascana Creek historical hydrograph
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Wascana Creek hydrograph 2014 –Qu’Appelle
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2011 hydrograph –Wascana Creek at Qu’Appelle
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Wascana Creek water level -2014 April 1-Aug
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Seven Bridges Road RM#189
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WWTP - outlet
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Scores overall lowered due to invasive plant species
Some species like smooth brome are too pervasive to be controlled
Expansion of other species like leafy spurge can be controlled
Evidence of flood damage leading to spread of invasive and disturbance plants
Interpretation of results – Invasive species
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Flow from WWTP has altered Creek hydrograph to flow year round
Impacts from recent high flows are pronounced
Potential impacts from stormwater flows from hard surface in Regina. High peak runoff events downstream
Phase 3 Downstream of Regina
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Constant flows are likely impacting establishment of vegetation, increasing erosive force on gravelly glacial soils
Recent major slumping at sites like Sherwood Forest and Deer Valley
Seven Bridges Road in RM #189 has serious erosion issues
Cottonwood Creek is healthy but now the receiving waterbody for the GTH stormwater system
Phase 3 downstream of Regina
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Total results for 3 phases 150 sites
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Healthiest sites are riparian park areas in Regina
Much engineering alteration in City and upstream, which may speed up water
Creek serves as natural pathway for invasives
Improvement will require cooperation and creativity
Overall results
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Some agricultural impacts, such as overspray with herbicide
No notable siltation from cropping No notable impacts from livestock overall Naturalization of parks and stormwater
channels helps manage city runoff Need more information about where flows
are coming from in the watershed
Overall results
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Questions?