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BMP Crosswalk — 2023 vs. 2026

Generated: 2026-03-12 Phase: 1 — Chapters 9–11 (BMP Library Pages)

Summary

Item Count
BMP entries 26
Parameters tracked 30
Verified from PDF 47
Unverified 13
Errors in register 11
Classification issues 9

Verification progress: 78% (47/60 era-parameter slots confirmed)

Values with verified: false have not been confirmed against OCR source PDFs.

Library Classification Issues

Library Page Library Chapter Manual Chapter Issue
subsurface-gravel-wetland.md ch9-small-scale-gi 11.5 Subsurface Gravel Wetlands are classified in the BMP Manual under Ch. 11 (Non-GI). The library places them in Ch. 9 (Sm…
extended-detention.md ch10-large-scale-gi 11.2 Extended Detention Basins are classified in the BMP Manual under Ch. 11 (Non-GI). The library places them in Ch. 10 (La…
rain-garden.md ch9-small-scale-gi Rain Garden is not a separate BMP Manual chapter. It is a lay term for small-scale bioretention (Ch. 9.7). All design c…
tree-trench.md ch9-small-scale-gi Tree Trench / Tree Box Filter is not a separate BMP Manual chapter in 2023 or 2026. It draws from 9.7 (small-scale bior…
hydrodynamic-separator.md ch11-non-gi 9.5 or 11.3 Hydrodynamic separators are a type of Manufactured Treatment Device (MTD). The BMP Manual addresses MTDs in Ch. 9.5 (Sm…
oil-grit-separator.md ch11-non-gi 9.5 or 11.3 Oil/Grit Separators are a type of Manufactured Treatment Device (MTD). Same as hydrodynamic separators — should cite Ch…
membrane-system.md ch11-non-gi Membrane systems are not a standalone BMP Manual chapter. May derive from Ch. 11.4 Sand Filters With Underdrain or spec…
dry-detention.md ch11-non-gi 11.2 Dry detention (extended detention without wet pool) is likely a variant of Ch. 11.2 Extended Detention Basins. There is…
underground-detention.md ch11-non-gi Underground detention (subsurface storage) is not a standalone BMP Manual chapter. May derive from Ch. 11.2 Extended De…

Parameter Crosswalk by BMP

bioretention

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/bioretention.md Type: direct 2023 source: Small-Scale Bioretention Systems (BMP Manual §9.7, doc: 2023_BMP_9_7) 2026 source: Small-Scale Bioretention Systems (BMP Manual §9.7, doc: 2026_BMP_9_7)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Contributing drainage area ≤ 2.5 acres ≤ 2.5 acres unchanged 2023:✓ 2026:✓ E-03
Maximum ponding depth 12 in 12 in unchanged 2023:✓ 2026:✓
Typical ponding depth 6 in 6 in unchanged 2023:✓ 2026:✓
Engineered media depth 18–48 in 18–48 in unchanged 2023:✓ 2026:✓
Filter media composition 60% sand / 20% topsoil / 20% compost 60% sand / 20% topsoil / 20% compost unchanged 2023:✓ 2026:✓
Drawdown time ≤ 72 hours ≤ 72 hours (24–48 hrs preferred) unchanged 2023:✓ 2026:✓
Underdrain required when Ksat < 0.5 in/hr or HSG C/D soils Ksat < 0.5 in/hr or HSG C/D soils unchanged 2023:✓ 2026:✓
SHWT separation 2 ft below bottom of media — measured from static SHWT 2 ft below bottom of media — measured from static SHWT unchanged 2023:✓ 2026:✓ E-09
K_design calculation K_design = K_field ÷ 2.0 (factor of safety = 2.0) K_design = K_field ÷ 2.0 (factor of safety = 2.0) unchanged 2023:✓ 2026:✓ E-10
Pretreatment required Required Required unchanged 2023:✓ 2026:✓

dry-well

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/dry-well.md Type: direct 2023 source: Dry Wells (BMP Manual §9.2, doc: 2023_BMP_9_2) 2026 source: Dry Wells (BMP Manual §9.2, doc: 2026_BMP_9_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Minimum Ksat (field-measured) ≥ 0.5 in/hr ≥ 0.5 in/hr unchanged 2023:✓ 2026:✓ E-04
SHWT separation 2 ft below dry well bottom — measured from static SHWT 2 ft below dry well bottom — measured from static SHWT unchanged 2023:✓ 2026:✓ E-09
Drawdown time ≤ 72 hours ≤ 72 hours unchanged 2023:✓ 2026:✓
Foundation setback ≥ 10 ft ≥ 10 ft unchanged 2023:✓ 2026:✓
Septic system setback ≥ 10 ft ≥ 10 ft unchanged 2023:✓ 2026:✓
Required infiltration test method Primary: percolation test, tube permeameter, single ring in… Primary: percolation test, tube permeameter, single ring in… unchanged 2023:✓ 2026:✓ E-06
K_design calculation K_design = K_field ÷ 2.0 (factor of safety = 2.0) K_design = K_field ÷ 2.0 (factor of safety = 2.0) unchanged 2023:✓ 2026:✓ E-10

cistern

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/cistern.md Type: direct 2023 source: Cisterns (BMP Manual §9.1, doc: 2023_BMP_9_1) 2026 source: Cisterns (BMP Manual §9.1, doc: 2026_BMP_9_1)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Storage capacity / sizing method unknown 2023:⏳ 2026:⏳
Chapter 14 volumetric reduction credit N/A — Ch. 14 did not exist Cistern + reuse system may qualify for volumetric reduction… new 2023:✓ 2026:✓

grass-swale

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/grass-swale.md Type: direct 2023 source: Grass Swales (BMP Manual §9.3, doc: 2023_BMP_9_3) 2026 source: Grass Swales (BMP Manual §9.3, doc: 2026_BMP_9_3)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Maximum side slope unknown 2023:⏳ 2026:⏳
Maximum longitudinal slope unknown 2023:⏳ 2026:⏳

green-roof

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/green-roof.md Type: direct 2023 source: Green Roofs (BMP Manual §9.4, doc: 2023_BMP_9_4) 2026 source: Green Roofs (BMP Manual §9.4, doc: 2026_BMP_9_4)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Growing media depth (extensive) unknown 2023:⏳ 2026:⏳
Volumetric reduction credit (Ch. 14) ET credit method (no Ch. 14) ET credit method via Ch. 14; cistern/reuse required to qual… modified 2023:⏳ 2026:✓

infiltration-basin

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/infiltration-basin.md Type: direct 2023 source: Small-Scale Infiltration Basins (BMP Manual §9.8, doc: 2023_BMP_9_8) 2026 source: Small-Scale Infiltration Basins (BMP Manual §9.8, doc: 2026_BMP_9_8)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Minimum Ksat unknown 2023:⏳ 2026:⏳
SHWT separation 2 ft — measured from static SHWT 2 ft — measured from static SHWT unchanged 2023:✓ 2026:✓ E-09
K_design calculation K_design = K_field ÷ 2.0 (factor of safety = 2.0) K_design = K_field ÷ 2.0 (factor of safety = 2.0) unchanged 2023:✓ 2026:✓ E-10

pervious-pavement

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/pervious-pavement.md Type: direct 2023 source: Pervious Paving Systems (BMP Manual §9.6, doc: 2023_BMP_9_6) 2026 source: Pervious Paving Systems (BMP Manual §9.6, doc: 2026_BMP_9_6)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Storage void ratio Maximum 0.40 unknown 2023:⏳ 2026:⏳
SHWT separation Measured from static SHWT Measured from static SHWT unchanged 2023:✓ 2026:✓ E-09

rain-garden

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/rain-garden.md Type: derived 2023 source: Small-Scale Bioretention Systems (lay term: rain garden) (BMP Manual §9.7, doc: 2023_BMP_9_7) 2026 source: Small-Scale Bioretention Systems (lay term: rain garden) (BMP Manual §9.7, doc: 2026_BMP_9_7)

Parameter 2023 Value 2026 Value Change Verified Conflicts

small-scale-sand-filter

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/small-scale-sand-filter.md Type: direct 2023 source: Small-Scale Sand Filters (BMP Manual §9.9, doc: 2023_BMP_9_9) 2026 source: Small-Scale Sand Filters (BMP Manual §9.9, doc: 2026_BMP_9_9)

Parameter 2023 Value 2026 Value Change Verified Conflicts

subsurface-gravel-wetland

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/subsurface-gravel-wetland.md Type: misclassified 2023 source: Subsurface Gravel Wetlands (Non-GI per Manual) (BMP Manual §11.5, doc: 2023_BMP_11_5) 2026 source: Subsurface Gravel Wetlands (Non-GI per Manual) (BMP Manual §11.5, doc: 2026_BMP_11_5)

Parameter 2023 Value 2026 Value Change Verified Conflicts

tree-trench

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/tree-trench.md Type: derived 2023 source: Small-Scale Bioretention (tree trench is a subtype) (BMP Manual §9.7, doc: 2023_BMP_9_7) 2026 source: Small-Scale Bioretention (tree trench is a subtype) (BMP Manual §9.7, doc: 2026_BMP_9_7)

Parameter 2023 Value 2026 Value Change Verified Conflicts

vegetated-filter-strip

Library page: Green-Guides/bmp-library/ch9-small-scale-gi/vegetated-filter-strip.md Type: direct 2023 source: Vegetative Filter Strips (BMP Manual §9.10, doc: 2023_BMP_9_10) 2026 source: Vegetative Filter Strips (BMP Manual §9.10, doc: 2026_BMP_9_10)

Parameter 2023 Value 2026 Value Change Verified Conflicts

ch10-large-bioretention

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/index.md Type: direct 2023 source: Bioretention Systems (BMP Manual §10.1, doc: 2023_BMP_10_1) 2026 source: Large-Scale Bioretention Systems (BMP Manual §10.1, doc: 2026_BMP_10_1)

Parameter 2023 Value 2026 Value Change Verified Conflicts
Contributing drainage area No explicit maximum in BMP Manual (small-scale cutoff at 2.… No explicit maximum in BMP Manual (small-scale cutoff at 2.… unchanged 2023:✓ 2026:✓ E-03

constructed-wetland

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/constructed-wetland.md Type: direct 2023 source: Standard Constructed Wetlands (BMP Manual §10.4, doc: 2023_BMP_10_4) 2026 source: Standard Constructed Wetlands (BMP Manual §10.4, doc: 2026_BMP_10_4)

Parameter 2023 Value 2026 Value Change Verified Conflicts

extended-detention-ch10

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/extended-detention.md Type: misclassified 2023 source: Extended Detention Basins (Non-GI per Manual) (BMP Manual §11.2, doc: 2023_BMP_11_2) 2026 source: Extended Detention Basins (Non-GI per Manual) (BMP Manual §11.2, doc: 2026_BMP_11_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts

infiltration-trench

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/infiltration-trench.md Type: direct 2023 source: Infiltration Basins (BMP Manual §10.2, doc: 2023_BMP_10_2) 2026 source: Infiltration Basins (BMP Manual §10.2, doc: 2026_BMP_10_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts
SHWT separation 2 ft — measured from static SHWT 2 ft — measured from static SHWT unchanged 2023:✓ 2026:✓ E-09

sand-filter-ch10

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/sand-filter.md Type: direct 2023 source: Sand Filters (Large-Scale GI) (BMP Manual §10.3, doc: 2023_BMP_10_3) 2026 source: Sand Filters (Large-Scale GI) (BMP Manual §10.3, doc: 2026_BMP_10_3)

Parameter 2023 Value 2026 Value Change Verified Conflicts

wet-pond-ch10

Library page: Green-Guides/bmp-library/ch10-large-scale-gi/wet-pond.md Type: direct 2023 source: Wet Ponds (Large-Scale GI) (BMP Manual §10.5, doc: 2023_BMP_10_5) 2026 source: Wet Ponds (Large-Scale GI) (BMP Manual §10.5, doc: 2026_BMP_10_5)

Parameter 2023 Value 2026 Value Change Verified Conflicts

blue-roof

Library page: Green-Guides/bmp-library/ch11-non-gi/blue-roof.md Type: direct 2023 source: Blue Roofs (BMP Manual §11.1, doc: 2023_BMP_11_1) 2026 source: Blue Roofs (BMP Manual §11.1, doc: 2026_BMP_11_1)

Parameter 2023 Value 2026 Value Change Verified Conflicts

dry-detention

Library page: Green-Guides/bmp-library/ch11-non-gi/dry-detention.md Type: derived 2023 source: Extended Detention Basins (dry detention variant) (BMP Manual §11.2, doc: 2023_BMP_11_2) 2026 source: Extended Detention Basins (dry detention variant) (BMP Manual §11.2, doc: 2026_BMP_11_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts

extended-detention-ch11

Library page: Green-Guides/bmp-library/ch11-non-gi/extended-detention.md Type: direct 2023 source: Extended Detention Basins (Non-GI) (BMP Manual §11.2, doc: 2023_BMP_11_2) 2026 source: Extended Detention Basins (Non-GI) (BMP Manual §11.2, doc: 2026_BMP_11_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts

hydrodynamic-separator

Library page: Green-Guides/bmp-library/ch11-non-gi/hydrodynamic-separator.md Type: derived 2023 source: Manufactured Treatment Devices (Non-GI MTD subtype) (BMP Manual §11.3, doc: 2023_BMP_11_3) 2026 source: Non-GI Manufactured Treatment Devices (MTD subtype) (BMP Manual §11.3, doc: 2026_BMP_11_3)

Parameter 2023 Value 2026 Value Change Verified Conflicts

manufactured-treatment-device

Library page: Green-Guides/bmp-library/ch11-non-gi/manufactured-treatment-device.md Type: direct 2023 source: Manufactured Treatment Devices (Non-GI) (BMP Manual §11.3, doc: 2023_BMP_11_3) 2026 source: Non-GI Manufactured Treatment Devices (BMP Manual §11.3, doc: 2026_BMP_11_3)

Parameter 2023 Value 2026 Value Change Verified Conflicts

membrane-system

Library page: Green-Guides/bmp-library/ch11-non-gi/membrane-system.md Type: derived 2023 source: Sand Filters (possible parent for membrane systems) (BMP Manual §11.4, doc: 2023_BMP_11_4) 2026 source: Sand Filters With Underdrain (possible parent for membrane systems) (BMP Manual §11.4, doc: 2026_BMP_11_4)

Parameter 2023 Value 2026 Value Change Verified Conflicts

oil-grit-separator

Library page: Green-Guides/bmp-library/ch11-non-gi/oil-grit-separator.md Type: derived 2023 source: Manufactured Treatment Devices (oil/grit separator subtype) (BMP Manual §11.3, doc: 2023_BMP_11_3) 2026 source: Non-GI Manufactured Treatment Devices (oil/grit separator subtype) (BMP Manual §11.3, doc: 2026_BMP_11_3)

Parameter 2023 Value 2026 Value Change Verified Conflicts

underground-detention

Library page: Green-Guides/bmp-library/ch11-non-gi/underground-detention.md Type: derived 2023 source: Extended Detention Basins (underground variant) (BMP Manual §11.2, doc: 2023_BMP_11_2) 2026 source: Extended Detention Basins (underground variant) (BMP Manual §11.2, doc: 2026_BMP_11_2)

Parameter 2023 Value 2026 Value Change Verified Conflicts