Shirley=S Brook and Watts Creek Subwatershed Study

Shirley=s Brook and Watts Creek Subwatershed Study

Report - Appendix A

SHIRLEY=S BROOK SUBWATERSHED FACT SHEETS

Catchment Area SB-1

Existing Environmental Conditions

Ground Water Resources

native subsoils not conducive to infiltration (minimal overburden and numerous bedrock out croppings)
within bedrock groundwater recharge area

Surface Water Resources

428 ha drainage area to Shirley=s Brook Tributary S1
intermittent baseflow
flood plain mapping is dated and does not extend upstream of March Road
known flood prone areas downstream of March Road

Water Quality

elevated TP
high E Coli & fecal coliforms
moderately elevated trace metals

Morphology

low-order tributary only in this Catchment Area
no obvious channel instability
cohesive banks
livestock access to channel downstream of March Rd.
no significant erosion sites present
poor riparian vegetation (grasses and cattails)
poorly defined bed morphology

Aquatic Resources

the stream reach within this Catchment Area does not constitute as fish habitat as it is an intermittent agricultural drain
this reach outlets into Type 2 habitat further downstream

Terrestrial Resources

contains three natural/woodlot areas. Area S1 is on the western edge of the Catchment Area and contains an excellent diversity of dry and wet forest that has been disturbed very little. The other two areas are of less importance as portions that have been cleared for estate residential development

Existing Land Uses

existing: open space and agriculture, small amount of low density residential and forest

Potential Development Impacts

Future Land Uses

development within the General Rural Area designation (increase of 293 ha of rural residential)
predicted increase in impervious area from 4% to 21%

Catchment Area SB-1 (Cont’d)

Groundwater Resources

as area is to remain largely rural, impacts limited to potential for quality impacts from on-site septic systems, road runoff, etc..
some potential quantity impacts due to increased usage but should be within acceptable limits

Surface Water Resources

increased runoff peak flows, aggravate existing flooding hazards
water quality impairment of receiving watercourses
for 2-year return period event, expected peak flow increase is 820 % over existing conditions
for 100-year return period event, expected peak flow increase is 387 % over existing conditions

Instream Water Quality

increase in TSS (from increased flows, erosion etc.)
moderate increase in E. Coli and Fecal coliforms
increased pollutant loading from vehicle traffic

Morphology

increased duration of low flow discharge B establishment of perennial channel is possible
increased incision into floodplain
increased sediment transport
increase erosion potential
widening of low flow channel: bank toe erosion
development of meandering plantform to occupy larger floodplain area

Aquatic Habitat

no significant impacts as fish habitat not present and little future development

Environmental Protection Targets

Surface Water Quality and Quantity

provide Level 2 water quality enhancement of urban storm water runoff
maintain post-development runoff peak flows to existing levels for all storm events up to the 100-year

Protection Level / Description / 2SWMP Type / 3Storage Volume (m3/ha) for Impervious Level
35% / 55% / 70% / 85%
Level 2 / Applied in areas of Type 2 fish habitat. Includes:
$aquatic habitat identified as ecologically valuable, but is sufficiently abundant or not considered to be a limiting factor for habitat productive capacity
$general feeding areas and pool-riffle-run complexes / Infiltration / 20 / 20 / 25 / 30
Wetlands / 60 / 70 / 80 / 90
Wet Ponds / 90 / 110 / 130 / 150
Dry Pond / 60 / 80 / 95 / 110

Note:1Source, Stormwater Management Practices Planning and Design Manual, (MOEE, 1994c)

2For wetlands and wet ponds, the required storage volume is comprised of 40 m3/ha extended detention, while the remainder is the permanent pool volume.

3Storage volumes are based on 24 hour detention.

Storage volumes are based on a 80, 70, 60 and 50% TSS removal for Protection Levels 1, 2, 3 and 4, respectively.

Catchment Area SB-1 (Cont’d)

Instream Water Quality

Parameter / Units / Recommended Criteria Level
Dissolved Oxygen / mg/L / > 3.0 mg/L
Temperature / o C / < 20 C change (in stormwater discharge)
PH / pH / 6.5 - 9.0
Total Suspended Solids (TSS) / mg/L / 10
Un-ionized ammonia / mg/L / 0.02
Total Phosphorus / mg/L / 0.03
Aluminum / mg/L / 0.3
Cadmium / mg/L / 0.0005
Copper / mg/L / 0.005
Lead / mg/L / 0.025
Zinc / mg/L / 0.03

Recommended Management Measures

Storm Water Management Practices

peak flows for 2 year to 100 year events to be controlled to pre-development levels

Catchment Area and Proposed Land Use / Source and Conveyance Controls / End-of-Pipe Controls
SB-1
Rural, residential, and natural area / Foundation drains discharged to the ground
Reduced lot grading / Rural road cross-sections
Grassed swales
Channel/outlet protection
Filter strips
Buffer strips / Wet ponds
Artificial wetlands
Hybrid ponds

Note:

$The final selection of infiltration facilities will require local soil and groundwater information.

$Reduced lot grade assumes a 1% slope (even for soils with infiltration capacity < 15 mm), compared to the current Kanata standard of 1.5%.

Morphology

protect low-order streams, increase conveyance control
no reduction in channel length
establish stream corridor based on belt width or comparable estimate
improve quality of riparian zone
develop set-back limits to meander belt width
ensure that entrenchment does not exceed 4
spacing of SWM along length of channel rather than downstream control
maintain drainage density

Catchment Area SB-1 (Cont’d)

Natural Area Protection and Restoration

none recommended for aquatic habitat
protect and maintain Natural Areas S14 and S13 as much as possible through a woodlot management plan to support linkages to other identified natural areas (identified as low priorities due to impacts from estate residential development). Area S1 identified as a priority for preservation

Catchment Area SB-2

Existing Environmental Conditions

Ground Water Resources

native subsoils not conducive to infiltration
within bedrock groundwater recharge area

Surface Water Resources

361 ha drainage area to Shirley=s Brook Tributary SB2
intermittent baseflow
flood plain mapping is dated and does not extend upstream of March Road
known flood prone areas downstream of March Road.

Water Quality

elevated TP
high E Coli & fecal coliforms
moderately elevated trace metals

Morphology

low-order tributary only, in this Catchment Area
majority of reach does not have any obvious channel instability
upstream of 2nd line Rd. the channel has been straightened
cohesive banks
extensive erosion sites where livestock access channel
poor riparian zone vegetation
no clearly defined pools or riffles
on-line ponds exist in upper and lower end of channel

Aquatic Resources

includes a combination of headwater areas with no defined channel (unlikely fish habitat). Reaches 1 and 2 potential Type 2 habitat due to intermittent nature of flow (Reach 3) and finally, a stretch of low quality Type 2 or Type 3 (Reach 4)

Terrestrial Resources

contains southern extension of natural area S1 (see Catchment Area S1) plus S12, and S11
S12 and S11 have been impacted by estate development

Existing Land Uses

forest and agriculture, small amount of low density residential

Potential Development Impacts

Future Land Uses

limited development in General Rural Area designation.
area of imperviousness to increase from2% to 15%
increase is predominately rural residential (129 ha) and some urban residential (43 ha)

Catchment Area SB-2 (Cont’d)

Groundwater Resources

as area is to remain largely rural, impacts limited to potential for quality impacts from on-site septic systems, road runoff, etc..
some potential quantity impacts due to increased usage but should be within acceptable limits

Surface Water Resources

increased runoff peak flows, aggravate existing flooding hazards
water quality impairment of receiving watercourses
for 2-year return period event, expected peak flow increase is 490 % over existing conditions
for 100-year return period event, expected peak flow increase is 215 % over existing conditions

Instream Water Quality

increase in TSS (from increased flows, erosion, etc.)
nutrients (TP, nitrates, etc..) Expected to decline due to decrease in agricultural activities
moderate increase in E. Coli and Fecal coliforms
increase pollutant loading from vehicle traffic

Morphology

increased duration of low flow discharge
increase in sediment transport
incision into floodplain
headwater erosion of the channel
widening of low flow channel: bank toe erosion
plantform development: increase lateral width of floodplain occupation
increased sedimentation of on-line ponds
increase flushing flows through channel
increase erosion potential

Aquatic Habitat

impacts in upper reaches are not expected as outside of urban boundary
bottom end of Reach 4 (just east of of March Road) has potential to be impacted from change in flows due to proposed new development (Kanata North Expansion Area)
decrease in habitat quality with potential increase in sedimentation and nutrients

Environmental Protection Targets

Surface Water Quality and Quantity

provide Level 2 water quality enhancement of urban storm water runoff
maintain post-development runoff peak flows to existing levels for all storm events up to the 100-year

Catchment Area SB-2 (Cont’d)

Protection Level / Description / 2SWMP Type / 3Storage Volume (m3/ha) for Impervious Level
35% / 55% / 70% / 85%
Level 2 / Applied in areas of Type 2 fish habitat. Includes:
$aquatic habitat identified as ecologically valuable, but is sufficiently abundant or not considered to be a limiting factor for habitat productive capacity
$general feeding areas and pool-riffle-run complexes / Infiltration / 20 / 20 / 25 / 30
Wetlands / 60 / 70 / 80 / 90
Wet Ponds / 90 / 110 / 130 / 150
Dry Pond / 60 / 80 / 95 / 110

Note:1Source, Stormwater Management Practices Planning and Design Manual, (MOEE, 1994c)

2For wetlands and wet ponds, the required storage volume is comprised of 40 m3/ha extended detention, while the remainder is the permanent pool volume.

3Storage volumes are based on 24 hour detention.

Storage volumes are based on a 80, 70, 60 and 50% TSS removal for Protection Levels 1, 2, 3 and 4, respectively.

Instream Water Quality

Parameter / Units / Recommended Criteria Level
Dissolved Oxygen / mg/L / > 3.0 mg/L
Temperature / o C / < 20 C change (in stormwater discharge)
pH / pH / 6.5 - 9.0
Total Suspended Solids (TSS) / mg/L / 10
Un-ionized ammonia / mg/L / 0.02
Total Phosphorus / mg/L / 0.03
Aluminum / mg/L / 0.3
Cadmium / mg/L / 0.0005
Copper / mg/L / 0.005
Lead / mg/L / 0.025
Zinc / mg/L / 0.03

Catchment Area SB-2 (Cont’d)

Recommended Management Measures

Storm Water Management Practices

peak flows for 2 year to 100 year events to be controlled to pre-development levels

Catchment Area and Proposed Land Use / Source and Conveyance Controls / End-of-Pipe Controls
SB-2
Rural and urban residential and natural area / $Foundation drains discharged to the ground
$Reduced lot grading / Rural road cross-sections
Grassed swales
Channel/outlet protection
Filter strips
Buffer strips / $Wet ponds
Artificial wetlands
Hybrid ponds

Note:

$Catchment areas with proposed development only, therefore areas SB-7, WC-3, 4, 5 are not included in the table.

$The final selection of infiltration facilities will require local soil and groundwater information.

$Reduced lot grade assumes a 1% slope (even for soils with infiltration capacity < 15 mm), compared to the current Kanata standard of 1.5%.

$Alternatives marked * should only be selected after site specific soil investigations. Infiltration basin should only be used where local soils have infiltration capability of > 60 mm

Morphology

Error! Bookmark not defined.no regulation of low flow events
protect low-order streams, increase conveyance control
ensure that entrenchment ratio does not exceed 4
no reduction in channel length
increase diversity and quality of riparian zone
establish a stream corridor based on meander belt widths or comparable measure
develop set-back limits to meander belt width
spacing of SWM along length of channel rather than downstream control
in-channel works to address existing erosion issues; improvement of bed morphology (inter-pool gradient should be ~ 10% less than bankfull gradient)
maintain on-line ponds to allow for natural regulation of flows
increase diversity of bed morphology

Natural Area Protection and Restoration

reach 4 recommended for restoration through natural cannel design; buffer to be increased along reach 3 through riparian plantings
natural area S1 identified as a priority for preservation
management recommendations for natural area S10 identified as a medium to high priority

Catchment Area SB-3

Existing Environmental Conditions

Ground Water Resources

native subsoils not conducive to infiltration (minimal overburden and numerous bedrock outcroppings)
northern half within bedrock groundwater recharge area

Surface Water Resources

609 ha drainage area to Shirley=s Brook main branch
intermittent baseflow
flood plain mapping is dated
known flood prone areas downstream of March Road

Water Quality

TSS high (>80 mg/L)
elevated TP
high E. Coli and fecal coliforms
moderately elevated trace metals

Morphology

extensive low-order stream drainage network, origin of main channel
fairly stable channel: narrow form with good riparian vegetation
upstream end of channel has been straightened, plantform alterations near CN rail embankment, downstream end appears natural
cohesive banks (silt/clay); bedrock sometimes close to channel
some within-channel vegetation that causes choking
poorly defined bed morphology (pool/riffle)
bed material varies from clay to cobbles, but is generally cohesive
swamp near Hydro corridor and on-line ponds, especially in the tributary channels (headwater)
woody debris observed throughout reach, debris jams upstream of Goulbourne Forced Rd.

Aquatic Resources

upper reaches are Type 1 (headwaters) and mid to lower reaches are Type 2

Terrestrial Resources

Much of this drainage area is covered by a 450 ha woodlot (S2) having the second highest score within the subwatersheds. Area has an excellent diversity of habitats.

Land Uses

predominately forest cover with some agriculture

Catchment Area SB-3 (Cont’d)

Potential Development Impacts

Future Land Uses

moderate increase in the amount of urban residential (121 ha) and industrial/commercial development (61 ha)
predicted increase in impervious area from 0% to 14 %

Ground Water Resources

potential impacts due to road runoff as well as non-specific commercial/industrial point sources (e.g., gas stations)

Surface Water Resources

increased runoff peak flows, aggravate existing flooding hazards
water quality impairment of receiving watercourses
for 2 year return period event, expected peak flow increase is 806%
for 100 year return period event, expected peak flow increase is 382%

Instream Water Quality

minimal impact anticipated due to limited development, nevertheless, slight increases in pollutant loading from vehicle traffic and slight increases in TSS and E. Coli/fecal coliforms can be expected

Morphology

incision into floodplain
increase in low flow channel width through bank toe erosion
increase in flushing flows to remove fines from channel
adjustments to channel plantform in straightened reaches upstream of Goulbourne Forced Rd. (increase in sinuosity will increase width of meander plantform)
increase in erosion potential

Aquatic Habitat

impacts in upper reaches are not expected as outside urban boundary
lower reaches (towards Golbourne Forced Road) have potential to be impacted from development ( e.g. erosion)
sedimentation resulting in overall decrease in habitat quality including interference of spawning activity of resident fish species

Environmental Protection Targets

Surface Water Quality and Quantity

provide Level 2 water quality enhancement of urban storm water runoff
maintain post-development runoff peak flows to existing levels for all storm events up to the 100-year

Catchment Area SB-3 (Cont’d)

Note:1Source, Stormwater Management Practices Planning and Design Manual, (MOEE, 1994c)

2For wetlands and wet ponds, the required storage volume is comprised of 40 m3/ha extended detention, while the remainder is the permanent pool volume.

3Storage volumes are based on 24 hour detention.

Storage volumes are based on a 80, 70, 60 and 50% TSS removal for Protection Levels 1, 2, 3 and 4, respectively.

Instream Water Quality

Parameter / Units / Recommended Criteria Level
Dissolved Oxygen / mg/L / > 3.0 mg/L
Temperature / o C / < 20 C change (in stormwater discharge)
PH / pH / 6.5 - 9.0
Total Suspended Solids (TSS) / mg/L / 10
Un-ionized ammonia / mg/L / 0.02
Total Phosphorus / mg/L / 0.03
Aluminum / mg/L / 0.3
Cadmium / mg/L / 0.0005
Copper / mg/L / 0.005
Lead / mg/L / 0.025
Zinc / mg/L / 0.03

Catchment Area SB-3 (Cont’d)

Recommended Best Management Practices

Storm Water Management Practices

peak flows for 2 year to 100 year events to be controlled to pre-development levels

Catchment Area and Proposed Land Use / Source and Conveyance Controls / End-of-Pipe Controls
SB--3
Urban residential, industrial/commercial and natural area / $Roof leader downspouts to grassed areas at industrial and commercial areas
$Foundation drains discharged to the ground
$Reduced lot grading
$Roof and parking lot storage
$Oil and grit separators / Grassed swales
Channel/outlet protection
Filter strips
Buffer strips / $Wet ponds
Artificial wetlands
Hybrid ponds

Note:

$The final selection of infiltration facilities will require local soil and groundwater information.

$Reduced lot grade assumes a 1% slope (even for soils with infiltration capacity < 15 mm), compared to the current Kanata standard of 1.5%.

Morphology

no regulation of low flow events to minimize erosion of channel
protect low-order streams, increase conveyance control
ensure that entrenchment is greater than 4

no reduction in channel length
maintain or enhance drainage density
protect riparian zone: develop a stream corridor based on meander belt width or on a comparable measure
develop set backs to the corridor
spacing of SWM along length of channel rather than downstream control
maintain on-line ponds and protect swamp at Hydro corridor to retain natural within-channel flow regulation
minimize watercourse crossings to reduce interference with the natural channel

Natural Area Protection and Restoration

natural process of restoration (from old agriculture to forest) should be maintained along Reach 6. For Reach 7, (Type 2 habitat) in addition to maintaining a 15m buffer, consider natural channel design as part of development plans. Although Reach 6 is intermittent, a 30 m buffers should be maintained, as it is a Type 1 habitat.
area S2 identified as a priority for preservation

Catchment Area SB-4

Existing Environmental Conditions

Ground Water Resources

small portion of Catchment Area contains subsoils that may be conducive to infiltration
much of drainage area (east half) within bedrock groundwater recharge area

Surface Water Resources

324 ha drainage area to Shirley=s Brook main branch
continuous baseflow
flood plain mapping is dated
known flood prone areas downstream of March Road, major spill zone to Kizell Drain
small on-line ponds through Kanata Research Park, not used for storm water management

Water Quality