Stormwater Atlas

City of Missoula

Montana Circular DEQ-8 — Subdivision Storm Water Drainage Standards

CityDEP / DEQMontanamediumNeeds reviewCitations verified

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Compare each cited field to the official PDF before relying on it. What this means

Municipality coverage via Montana DEQ-8 (Helena pattern).

Other manuals in Montana: City of Helena, Montana, Montana, Montana

Document Metadata

Jurisdiction level
City

No evidence cited

State
Montana

No evidence cited

Version / edition
2024 Edition

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Adoption / effective date
2024

No evidence cited

Last revised date
2024

No evidence cited

Relationship to state manual
adopts state manual directly

No evidence cited

Design Criteria

Design storm return periods (years)
2-year, 10-year, 100-year

No evidence cited

Water quality volume method
Initial Storm Water Facility must infiltrate, evapotranspire, and/or capture for reuse post-development runoff from the first 0.5 inches of rainfall on impervious areas (V = 0.5 × Aimp / 12).

No evidence cited

Peak flow calculation method(s)
Rational Method, TR-55 / SCS Curve Number Method, Storage-Indication Routing

No evidence cited

Hydrologic/hydraulic software
Not found in document

No evidence cited

Approved BMP categories
Initial Storm Water Facility, Retention / Detention / Infiltration, Bioretention

No evidence cited