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CITY OF KAMLOOPS
SUSTAINABLE KAMLOOPS PLAN
INFORMATION PACKAGE ON WATER
(Final Version)
STORMWA TER
Background
Rain and snow are ty pically absorbed by the soil on which they fall. A s the water infiltrates the
soil a number of benefits occur. The infiltration process filters contaminants from the water,
replenishes soil moisture and recharges ground water aquifers (an underground lay er of rock ,
sand or grav el through which water can flow). But what about snow and rain that fall on hard
surfaces lik e pav ed streets, park ing lots and roof tops? The water running off from these areas is
called stormwater, and it is not absorbed by the soil. Instead, it generally flows into the nearest
drainage sy stem (storm sewers) and is directed into waterway s.
When the v olume of stormwater is too great for the storm sewers to accommodate, streets and
other urban areas can quick ly flood. A lso, as stormwater washes through the streets it tends to
pick up and transport whatev er it encounters – spilled oil, detergents, solv ents, salt, pet wastes
and so forth. This contaminated stormwater is usually not treated before it reaches riv ers and
lak es. Introduction of these contaminants to water bodies can lower water quality , cause an
ov erabundance of algae, and reduce aquatic life.
While Kamloops does not receiv e a lot of rain or snow, there are factors which lead to concern
ov er stormwater management in our community:

The intensity of storms we are experiencing hav e increased mark edly , possibly due to
climate change. This trend is shown on the following graph (data from A irport monitoring
station);
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
Our distinct geography , including soil characteristics in areas such as A berdeen and along
the silt bluffs ex tending from Valleyv iew to Campbell Creek , creates special challenges.
Major drainage basins in Kamloops are shown on the map on the following page.

The loss of v egetation due to pine beetle infestation has diminished the ability of our
landscape to absorb moisture.
There are a number of link s between stormwater management and community sustainability ,
including:

Env ironmental impacts resulting from degraded water quality link ed to contaminants in
stormwater, as well as erosion of streambank s and riparian habitats due to intensified
stormwater flows;

Economic and social effects which result if property damage occurs in flood conditions.
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Baseline Conditions
Stormwater in managed in two main way s in Kamloops:

In areas such as the City Centre, Sahali, A berdeen and the Southeast Sector, stormwater is
collected by drainage catch basins, conv ey ed to storm sewers, and piped directly to creek s
(such as Peterson and Guerin) and discharged to the Thompson Riv ers;

In other areas such as North Kamloops and Brock lehurst, there is limited stormwater
infrastructure and water drains uncontrolled into the nearest porous surface (ie. lawns,
trees, gardens, etc.). This is a similar situation in rural areas.
This approach to stormwater management (especially for the City Centre, Sahali and similar
areas) is illustrated in the following diagram.
A dditional baseline conditions to be established include:

Number of stormwater outfalls into the North, South and Mainstem Thompson Riv ers in
Kamloops;

Proportion of City serv ed by a stormwater collection sy stem (ie. catch basins, pipe network
and outfall), and proportion serv ed by an infiltration sy stem where stormwater seeps into the
nearest porous surface;

Stormwater quality in k ey drainage courses (such as Guerin and Peterson Creek s);

Proportion of City considered to be imperv ious area.
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Goals
The City of Kamloops has recently dev eloped a new guiding document for approaching
stormwater management. A k ey goal of this work is to mov e toward a more sustainable method
of managing stormwater, as illustrated in the following diagram.
In adopting this new approach, further goals will include:

Integrating planning and implementation activ ities with other considerations, such as land
use planning, env ironmental protection and financing of required infrastructure;

Considering env ironmental protection and enhancement as a top priority ;

Understanding the current water quality situation in stormwater drainage channels;

Remaining context-sensitiv e to the div ersity of geographic conditions in Kamloops;

Enhancing funding av ailable to support stormwater management activ ities through the
creation of a stormwater utility .
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Targets
The stormwater management guiding document contains a number of recommended targets in
areas related to land use planning, financing, operations and other dimensions of this topic.
Specific stormwater control targets are summarized below.
The City should adopt targets for stormwater control that focus on runoff rate and volume and
on runoff quality . A “dual target” sy stem which will allow different classes of dev elopment or
land use to meet stormwater management goals in an efficient manner is suggested. For
commercial, industrial, institutional and multi-family residential dev elopment (including
redev elopment), the use of performance standards could include:

For small storms (less than 12 mm in 24 hours): Capture and retain on site all rainwater
for reuse, infiltration, ev aporation and/or transpiration.

For medium storms (between 12 mm and 24 mm in 24 hours): Capture and detain for
slow release the next increment of stormwater exceeding that specified for small storms.

For large storms (greater than 24 mm in 24 hours):
Prov ide safe conv ey ance of all
stormwater, in agreement with the applicable Master Watershed Plan.

On an av erage basis, remov e 80% of Total Suspended Solids (TSS) down to 50 micron
particle size.

On an av erage basis, limit discharge of Oil & Grease to less than 10 mg/L.
For single family residential dev elopment (including redev elopment), the use of a prescriptiv e
standard is recommended, by which specific low impact BMPs must be installed or used on
residential lots and local streets:

Place 150- 200 mm of amended topsoil prior to seeding or sodding on lots and boulev ards

Meet minimum tree retention and planting requirement

Direct roof leaders to ground (not a storm sewer) or to a perforated pipe placed in the y ard

Install bioswales and/or rain gardens for street runoff, with ov erflows to the storm sewer
A dditional targets articulated in this document which hav e bearing on the goals expressed abov e
deal with issues such as creation of basin plan s using the integrated planning approach,
monitoring stormwater quality , exploring establishment of a stormwater utility , rev ising City
policies and regulations, and ensuring the protection of property .
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Proposed Directions
City Influencing Community

Enhance public awareness and education of the importance of stormwater management in
recognition both of the low profile of this issue in Kamloops’ semi-arid env ironment, and y et
its importance giv en its resource potential, climate change, and env ironmental
considerations;

Encourage stormwater capture and, if necessary , treatment to render it a v aluable water
resource;