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Site Constraints Analysis

Site constraints analysis builds the factual record that later BMP selection and sizing depend on. In the live source set, that record is anchored to Chapter 12 soil-testing criteria and the hydraulic-impact framework for infiltration into subsoil.

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

What Must Be Established

The current source-backed minimum record includes:

  • field-supported soil and permeability information at the proposed BMP location
  • seasonal high water table evidence suitable for design use
  • the physical and regulatory conditions that affect whether infiltration into subsoil is supportable
  • enough subsurface information to decide whether Chapter 13 hydraulic-impact review is needed

Source-Backed Checkpoints

The minimum evidence chain for this stage is stronger than a generic geotechnical summary. The live source set expects the design team to leave this stage with answers to the following:

Checkpoint What has to be known before moving on
Soil evidence Whether the Chapter 12 exploration and testing record supports infiltration design values
SHWT evidence Whether the SHWT has been established by the Chapter 12 methods suitable for design use
Infiltration trigger Whether the proposed strategy infiltrates into subsoil and therefore triggers hydraulic-impact review
Feasibility boundaries Whether site conditions force lined, underdrained, or non-infiltration alternatives

Why This Comes First

The source set does not support treating these constraints as cleanup items after a preferred BMP has already been chosen. They control whether infiltration-based BMPs remain viable and whether the project can credibly claim recharge or volumetric-reduction benefits.

At the page level, the key screening questions are:

  1. Is the soil evidence chain strong enough for infiltration design?
  2. Is SHWT separation adequate for the proposed BMP configuration?
  3. Does infiltration into subsoil trigger hydraulic-impact review?
  4. Are there site conditions that push the project toward lined, underdrained, or non-infiltration alternatives?

Workflow Effect

The output of this stage is not just a soil memo. It determines what the later pages are allowed to say:

  • Hydrologic Analysis depends on the site evidence chain
  • BMP Selection uses this stage to keep infeasible BMPs off the shortlist
  • BMP Sizing depends on the credited design permeability and hydraulic-impact framework

The practical deliverable from this stage is therefore a defensible feasibility record, not just a preliminary preference for one BMP type.