Underground Detention¶

This page is a source-backed entry point for the underground-detention concept, but the live citations layer resolves it through BMP Manual Chapter 11.2 rather than through a standalone underground-detention chapter. The page therefore treats it as a derived detention application anchored to the extended-detention source bundle.

Structured citation evidence for this page lives in the sibling claim manifest.

Overview¶

In the live source set, underground detention is best read as a subsurface application of the Chapter 11.2 detention framework. The source-backed emphasis is on storage and controlled release, not on GI or recharge performance.

Source Mapping¶

This route is retained for site navigation, but the live citations layer flags a taxonomy or classification caution for it.

Route caution: Underground detention (subsurface storage) is not a standalone BMP Manual chapter. May derive from Ch. 11.2 Extended Detention Basins or Ch. 5 computations. Source needs identification.
Route type: derived
2023 source bundle: Chapter 11.2 (2023_BMP_11_2) - Extended Detention Basins (underground variant)
2026 source bundle: Chapter 11.2 (2026_BMP_11_2) - Extended Detention Basins (underground variant)
Source-basis note: Underground detention is not a standalone BMP Manual chapter. Typically a subsurface application of extended detention (Ch. 11.2). Source and scope need documentation.

Key verified claims already tied to this page manifest: - Underground detention is source-derived from Chapter 11.2 rather than from a standalone chapter. - Underground detention stays a Chapter 11.2 detention application rather than a separate source authority. - Underground-detention maintenance remains tied to the Chapter 11.2 detention framework.

Design Criteria¶

The reconciled design criteria below come from the live crosswalk and page-level claim set, not from the older narrative snapshot.

This route does not have a dedicated parameter table in the crosswalk, so the controlling criteria stay tied to the verified claims and canonical source-bundle mapping below.

Source-backed criteria that still control this route: - Underground detention is source-derived from Chapter 11.2 rather than from a standalone chapter. - Underground detention stays a Chapter 11.2 detention application rather than a separate source authority. - Underground-detention maintenance remains tied to the Chapter 11.2 detention framework.

Siting Constraints¶

The current source-backed siting review should focus on:

whether a subsurface detention layout is really being designed within the Chapter 11.2 detention framework
whether access, inspection, and sediment-removal logistics are realistic
whether the page is being used to overstate recharge or GI value that the source basis does not support

Maintenance¶

Maintenance remains access-centered:

preserve inspection and cleanout access
monitor sediment buildup and outlet behavior
treat blocked access or hidden performance loss as a core operating risk

Source Bundles¶

Use these source bundles when checking the live extracted text or paired OCR evidence:

2023 bundle: Chapter 11.2 (2023_BMP_11_2) - Extended Detention Basins (underground variant)
2026 bundle: Chapter 11.2 (2026_BMP_11_2) - Extended Detention Basins (underground variant)