City of Roanoke

Stormwater Management Design Manual — Chapter 5 Stormwater Hydrology (+ Ch.12 WQ)

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

Manual is chaptered; ingested Ch.5 hydrology PDF plus Ch.12 pollutant-removal criteria from city DocumentCenter. Prefer full combined PDF if published later.

Other manuals in Virginia: Arlington County, City of Alexandria, City of Charlottesville, City of Chesapeake, City of Norfolk, City of Richmond, Fairfax County, Virginia Department of Environmental Quality (DEQ), Virginia Department of Transportation (VDOT)

Document Metadata

Jurisdiction level

City

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State

Virginia

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Version / edition

Revised July 1, 2014 (manual Oct 1, 2007 base)

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Adoption / effective date

2014-07-01

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Last revised date

2014-07-01

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Relationship to state manual

deemed equivalent to state manual

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Design Criteria

Design storm return periods (years)

2-year, 10-year, 25-year, 100-year

“Open Channels: Minor Channel Capacity 10-year ... Major Channel Capacity 100-year ... Culverts: Principal Arterial Roads 25-year Other Roads 10-year ... Storm Drains: 10-year”
§5.2.2

Water quality volume method

Ch.12: stormwater quality BMPs per DEQ BMP Clearinghouse; runoff reduction method / water quality compliance worksheet per 9VAC25-870-65. Phosphorus removal is primary design target (assumes metals/TSS also controlled). Channel protection and flood protection for SWM facilities per 9VAC25-870-66. Hydrology Ch.5: open-channel minor 10-year (lining 2- or 10-year by size), major 100-year; culverts 10-/25-year; storm drains 10-year; check 100-year where flooding risk.

“runoff reduction method will be utilized. A water quality compliance worksheet ... 9VAC25-870-65”
Ch.12 §12.3

Peak flow calculation method(s)

Rational Method (with Cf for storms >10-year), SCS Method / hydrographs, VDOT Drainage Manual / VA SWM Handbook references, Anderson Method (as applicable)

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Hydrologic/hydraulic software

Not found in document

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Approved BMP categories

Virginia BMP Clearinghouse practices, Manufactured BMPs (Clearinghouse-listed only), Retention / detention (Ch.10), Open channels / culverts / storm drains

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