HomeMy WebLinkAboutEnv - 2016-02-18 - Item 2 - 2015 Stormwater Management Audit Results
Executive Summary
The City of Kitchener completed the Kitchener Stormwater Policy Development program in 2001 which
culminated in a report detailing the existing stormwater management (SWM) infrastructure. This program
outlined new policies to manage, monitor and improve stormwater management within the City. As part of
the Annual Audit, a stream monitoring program, including both biological and chemical monitoring
components was initiated in 2002.
The 2015 monitoring program was developed from the recommendations contained within the 2014 SWM
Audit (AECOM, 2014) and was built upon monitoring data collected from 2002 through 2014, continuing
to gather data from core stations monitored in the previous years. The 2015 sampling program included
grab sampling and/or auto sampling for chemistry and bacteriology, benthic and fish sampling, continuous
depth and temperature monitoring.
Physical and Chemical Analysis
Grab sampling included one (1) spring melt, five (5) wet and five (5) dry sampling events at eight
locations including Kolb Creek (KD1), Montgomery Creek (MG1), Strasburg Creek (SB13a), Sandrock
Greenway (SR2), Shoemaker Greenway (SM1), and Idlewood Creek (IW1). ISCO automated sampling
devices were installed at Strasburg Creek (SB2) and Henry Strum Creek (HS1). Continuous stage and
temperature measurements collected using a HOBO U20 pressure transducer at 15 minutes intervals.
Table ES-1 summarizes the results of the 2015 SWM Audit monitoring. Annual average and maximum
values of parameters are shown at each station. Exceedances of average and/or value from respective
guidelines have been identified as bold fonts and colored cells, respectively. Average concentrations of
chloride have exceeded the chronic guideline at all streams except Strasburg and Blair Creek stations.
Total phosphorus average concentrations also exceed the guideline at most streams except Montgomery
and Kolb Creek (where maximum concentration exceed the guideline). Maximum dissolved phosphorus
concentrations exceed the guideline for total phosphorus in many stations, too. Total suspended solids
and to some extent metals (lead, copper and zinc) exceed their respective guidelines in Blazer, Hidden
Valley, Idlewood, Strasburg (SB2), Shoemaker and Sandrock.
Table ES-1: Summary of 2015 SWM Audit Monitoring Results
Notes:
All values are in mg/L
Concentrations are shown as: Average (Maximum) values
Exceedance of average concentration is shown through bold fonts
Exceedance of maximum concentration is shown through highlighted cells.
Temperature monitoring resulted in the classification of Henry Strum and Strasburg Creeks as cool-warm
water and cool water, respectively.
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Flow Measurement
Discrete flow measurements and corresponding flow depths were recorded during water quality sampling,
on five (5) occasions for HS1 and SB2. The continuous water level data collected at station Kolb HS1 and
SB2 was translated from water levels to flow rates by utilizing the relative flow versus depth relationship.
Continuous flow monitoring data was normalized using barometric pressure.
Trends
Stations with eight (8) years or more of data that were involved in both wet and dry sampling events in
2015 were compared with historical data for wet and dry sampling events. These stations included
Strasburg 2 (SB2), Henry Strum 1 (HS1), Kolb Creek (KD1), Montgomery (MG1) and Sandrock (SR2).
Time series are provided for TSS and chloride. Metals and nutrients are generally correlated with TSS
and follow the same patterns. A summary of the analysis result is as follows:
SB2: no long-term trend is observed in this station for TSS and chloride with concentrations being
generally below respective guidelines.
HS1: wet weather measurements of TSS have been high since 2008, at which point it reached a
concentration of 2100 mg/L. since. Dry weather concentrations of chloride started to increase from
around 120 mg/L to a few hundred in 2008.
KD1: wet weather measurements of TSS have climbed to vales above 100 mg/L since 2009. Both dry
and wet weather concentrations of chloride have been above the CCME guideline of 120 mg/L since
2009.
MG1: wet weather measurements of TSS have climbed to vales about 140 mg/L since 2009. Chloride
concentrations during both wet and dry weather events have been hovering around 400 mg/L with some
wet years falling below the CCME guideline of 120 mg/L for chronic toxicity.
SR2: wet weather measurements of TSS increased from earlier lower values to about 300 mg/L in 2012
and 150 mg/L in 2015. Dry weather concentrations of chloride have general been between CCME
guidelines of 120 and 640 mg/L for chronic and acute toxicity, respectively, with one sample reaching
2100 mg/L in January 2012. No specific trend is observed for TSS or chloride.
Biological Sampling
Benthic macroinvertebrate and fish sampling was conducted at the eight stations listed above.
Given that it is difficult to determine specific thresholds for the number (or percentage) of organisms for
each metric that should be found in an unimpaired stream sample, the samples were compared to one
other by stream. Samples collected within each watercourse were also measured against the First and
Second Five Year Report Card to note any changes in the benthic data over time.
Aquatic invertebrate samples collected as part of the 2015 Kitchener Stormwater Monitoring Program
yielded similar results to the previous years. Shoemaker Greenway (SM1) scored highest in two metrics
(% EPT and % Clingers), and second highest in three metrics (% Dominant, % Scrapers and HBI); the
results suggest that Shoemaker Greenway (SR2) has the highest overall water quality within the study
area. Montgomery Creek (MG1) and Strasburg Creek (SB2) each scored highest in two metrics,
suggesting good overall water quality at these locations as well. Kolb Creek (KD1) had the lowest overall
water quality, scoring lowest in three indices (% EPT, % CL and the Shannon Diversity Index).
Over the past three years, the overall quality of Montgomery Creek (MG1) and Strasburg Creek (SB2)
has increased for all indices measured. Overall water quality in Strasburg Creek (SB2) plummeted in
2014 from its 2013 conditions, but results revealed a marked improvement in 2015. Values increased
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dramatically in Strasburg Creek (SB2) for almost all water quality indices from 2014 to 2015, and this
watercourse is once again considered to have one of the healthiest biological communities of the eight
sites examined for the purpose of this study. While water quality has generally improved in Montgomery
Creek (MG1) and Strasburg Creek (SB2) since 2013, this is not the case for Sandrock Greenway (SR2).
The 2015 fish sampling revealed a fish community similar to that of past monitoring years. Strasburg 2
(SB2) scored highest in % Intolerant Species, which is a result of the presence of Brook Trout, a highly
sensitive species to pollution. Species density was highest at Kolb Creek (KD1), with a variety of tolerant
and intermediately tolerant coolwater and warmwater species identified. No fish were captured at
Shoemaker Greenway (SM1) for the second consecutive year, and as a result this watercourse scored
low in all metrics. The majority of the species captured at Strasburg 2 (SB2) are coolwater species, with
the exception of Brook Trout and Mottled Sculpin (Cottus bairdii) which are coldwater species. The fish
community in Montgomery Creek (MG1) is transitioning from a diverse assemblage containing many
different fish species to a community dominated by only a few tolerant species. In
2015, a higher number of individuals were captured in Strasburg Creek (SB2) and Sandrock Greenway
(SR2) than during the previous two sampling years. However, species richness (as well as the other
indices measured) has remained more or less consistent since 2013.
Biological Monitoring tasks were undertaken as part of the Balzer Creek Class Environmental
Assessment (Ecosystem Recovery 2015) and suggested an overall “Fair” stream condition with a low to
moderate degree of species diversity.
Sediment Volume
In order to estimate the sediment volumes, an existing surface survey was constructed using a
combination a of total station survey and sonar technology. The results were compared to the design
bottom surface of the stormwater management pond, which were either as-constructed information
(design drawings provided by the City), or the bottom surface surveyed in 2008. The volume comparison
in six ponds (excluding wetlands
showed that the volume above the full volume is greater than 200 m
3
and dry ponds), including Ponds 41, 53, 57, 80, 100 and 101. These ponds are identified as having
priority for cleaning.
Non-Point Source Pollution and Best Management Practices
A discussion of non-point sources of pollution and Best Management Practices (BMPs) have been
provided for urban non-point sources to the Grand River. Existing BMP databases were reviewed to
provide recommendations for best opportunities for improving water quality in the City of Kitchener.
In 2014, AECOM prepared a Best Practices Guide for Reducing Urban Non-Point Source Pollution in the
Grand and Speed Rivers for the GRCA, through which, a literature review was completed indicating that
the water quality of the water courses in the study area is reflective of the regional geology, land use, land
management practices, and seasonal weather conditions. It also identified a wide variety of operations
and maintenance (O&M), infrastructure, and planning enhancements of stormwater management headed
by the area municipalities. These stormwater management enhancements include each of the
municipality‘s stormwater infrastructure Geographic Information System (GIS) availability, transportation
corridor maintenance (i.e., street sweeping, leaf collection, catch basin cleanouts, and road salting
operations), SWM infrastructure inventory and maintenance practices, and monitoring
programs. The guideline identified three key objectives (themes) and 13 recommendations for reducing
urban NPS pollution; a summary of which is provided in this report.
Providing more specific recommendations requires a detailed knowledge of urban non-point sources
(which may be obtained from the proposed GRCA/City/Region study) and analysis of pollution loads
(estimated using EMC data).
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Recommendations
The recommendations for the 2016 SMW Audit were developed based on the recommendations for 2015-
2019 contained within the 2014 SWM audit by AECOM, the results of the 2015 SWM Audit Program, as
well as discussion with the Steering Committee members. These include:
Establishment of the two existing flow proportionate sites at Stations SR2 (Sandrock) and SM1
(Shoemaker); Autosamplers are also recommended at Balzer Creek and Idlewood Creek to monitor
changes associated with construction activities, to be completed under the project umbrella (outside of
the scope of the 2016 SW Audit);
Monitoring stations for collection of grab samples at locations where EMCs have already been
established i.e. Henry Sturm 1 (HS1), Kolb Creek 1 (KD1), Montgomery 1 (MG1), Strasburg 2 (SB2), and
Strasburg 13a (SB13a);
Review of the long-term monitoring program in light of the City of Kitchener’s Integrated Stormwater
Management Plan (ISWMP; to be released in 2016). Landuse and future and/or active projects and
programs should be considered in the determination of monitoring needs.Specific recommendations
include:
i. To place autosamplers strategically, and aim at producing long-term continuous data (rather
than at 5-year cycles) at a limited number of stations. Generally speaking at least 10
consecutive years of data is required for establishment of trends. As more autosamplers
become available, the program can be extended to other stations;
ii. In order to interpret the monitoring results correctly, it is important to identify site-specific
receiving water targets (when applicable), and a reference station (to establish baseline
conditions). It is understood that these are being identified under the ISWMP, and therefore
the Plan needs to be consulted when interpreting the monitoring results; and
iii. The GRCA, in partnership with City of Kitchener, City of Waterloo and Region of Waterloo,
are initiating a study in 2016 to characterize urban nonpoint source pollution in the Middle
Grand River, using existing water monitoring data. It is recommended that the consultant
responsible for the 2016 Audit be informed of that process in order to apply the insight gained
in revising the long term program.
Biological monitoring, including fish and benthic invertebrate surveys, are recommended for all stations
monitored for water quality. The purpose of this component is to document changes in habitat quality
over time which may indicate changes in water quality and watershed conditions. Such changes may
trigger the need for additional monitoring or recommendations to update the established EMC for a
specific station demonstrating evidence of change
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