Credit scorecard — Mississauga bylaw
Each category awards a maximum percentage of the annual stormwater charge as credit.
Evidence is extracted directly from the source PDF — no manual review.
✓Peak Flow
pre-vs-post controlled across multiple storms; avg reduction 7%
40%
✓Water Quality
TSS removal 80% (enhanced)
30%
✓Runoff Volume
water balance retains 5 mm on site (2% per mm, max 30% at 15 mm)
30%
—Operations
combinable O&A sub-credits — not documented
0%
Net credit
Capped at 50% of annual stormwater charge
50%
Pre vs post peak discharge
| Storm event | Pre-dev (m3/s) | Post-dev (m3/s) | Δ |
|---|
| 2-yr | 0.233 | 0.221 | −5% |
| 5-yr | 0.313 | 0.297 | −5% |
| 10-yr | 0.386 | 0.366 | −5% |
| 25-yr | 0.488 | 0.462 | −5% |
| 50-yr | 0.594 | 0.563 | −5% |
| 100-yr | 0.684 | 0.649 | −5% |
| Regional (Hurricane Hazel) | 0.321 | 0.255 | −21% |
Stormwater controls (6)
Underground storageNorth Building SWM Tank
Storage volume20.0 m³
Treatment volume36.0 m³
Outletorifice
375mm orifice tube, max head 0.9m, restricts 100-year post-development flow to 401 L/s. Quantity control volume 10 m3, water balance dead storage 36 m3. Total tank approximately 20 m3 for quantity control plus 36 m3 water balance.
Underground storageSouth Building SWM Tank
No quantity control orifice required for South Building. Water balance dead storage of 8 m3. Contains media filtration unit (e.g. Jellyfish) for quality treatment.
InfiltrationMedia Filtration Unit (Jellyfish) - North Building
Media filtration unit within underground foundation structure to treat at-grade asphalt runoff before quantity control tank.
InfiltrationMedia Filtration Unit (Jellyfish) - South Building
Media filtration unit within underground foundation structure to treat at-grade asphalt runoff.
SwaleDry Swale - Catchment 204
Dry swale without underdrain along top of bank in Catchment 204, conveying runoff over grassed surfaces to proposed catchbasin on south side of site. Provides natural infiltration and TSS removal.
Rainwater harvesting / reuseSite-wide Rainwater Harvesting for Irrigation
Storage volume44.0 m³
Outletother
44 m3 total water balance storage split between North (36 m3) and South (8 m3) building underground tanks. Stored rooftop runoff pumped for irrigation during summer months.
Best management practices (6)
Underground storage tankMedia filtration unit (Jellyfish filter)Dry swale (without underdrain)Rainwater harvesting for irrigationRe-naturalization/revegetation of floodplain areaPervious stable surfaces
Site characteristics & report metadata
Project66 Thomas Street Residential Development
Project typeRedevelopment
DeveloperDe Zen Realty Company Ltd.
PermitDARC 24-170 W11
Existing land useindustrial/commercial (existing buildings, paved parking and storage areas)
Proposed land usemixed residential (multi-storey residential towers with underground parking)
Site area2.78 ha
Impervious99% (pre) → 83% (post)
Water balance capture5.0 mm
TSS removal target80%
Quality control methodtreatment train: media filtration unit (Jellyfish) + underground storage tank settling (0.15m depth reserved) + dry swale for landscaped catchment
Extraction audit
Confidence: high
Completeness: 100%
Source: 85-page PDF
Extractor: PARCELFLOW v1
Validation: passed
Source PDF: Functional-Servicing-and-Stormwater-Management-Report-oz-opa-25-3-w11-january-2025.pdf (85 pages)
Open source PDF →
Starter package
Download credit application package »
10-page PDF: pre-filled Form 2703, starter P.Eng report skeleton, submission checklist. Engineer reviews, adds site inspection + O&M plan, certifies + submits.
Download PDF »
How to read this page. Every value above was extracted from the source PDF by the
PARCELFLOW report parser, which combines a layout-robust template detector with a
validated extraction stage tuned to Ontario Functional Servicing and Stormwater
Management reports. The four-category scorecard maps the parsed evidence onto
Mississauga's credit bylaw. Numbers are estimates — engineering review still required
before submitting a formal credit application to the City.