4.1 Introduction

The LID BMPs in this Chapter include tools used for water quality treatment and/or flow control. By using the site inventory, analysis, and planning practices described in Chapter 2: Planning for LID and Chapter 3: Designing for LID, the BMPs included in this Chapter can be designed as landscape amenities that take advantage of site topography, existing soils and vegetation, and location in relation to impervious surfaces to reduce stormwater volume, attenuate and treat flows, and help mimic the natural site hydrologic patterns.

This Chapter includes design guidance on the following LID BMPs:
4.2 Amending Construction Site Soils
4.3 Dispersion
4.4 Bioretention
4.5 Trees
4.6 Permeable Pavement
4.7 Vegetated Roofs
4.8 Minimal Excavation Foundations
4.9 Rain Water Harvesting

Each section begins with a description of the BMP and the intent behind its use. Following this general description are seven sub-sections, as follows:
    Applications and Limitations.
    Runoff Model
    Infeasibility Criteria.

Local jurisdiction requirements on applications and limitations, design, sizing, infeasibility criteria, and maintenance should be used as the basis of design and implementation, unless deviations are approved locally. The sub-section on runoff model representation provides guidelines for modeling the flow control and/or treatment benefits of the LID BMPs and instructions on how to adjust site-wide hydrologic models to evaluate reduced downstream BMP requirements as a result of implementing LID on-site.