Post-Construction Storm Water Runoff Management

Post Construction Stormwater Management Requirements (PCRs)

On July 13, 2013, the Central Coast Regional Water Quality Control Board adopted the Post-Construction Stormwater Management Requirements (PDF) (Resolution R3-20132 to 0032025).

Stormwater Technical Guide

Applicants for development approvals in jurisdictions within the Paso Robles Stormwater Management Program should use the Stormwater Technical Guide when preparing Stormwater Control Plans. However, local requirements vary. Check with staff in the jurisdiction where your project is located to identify differences that may apply. A pre-application meeting is recommended for all projects subject to the PCRs.

Requirements at a Glance

Type of Project Performance Requirements
Tier 1: Projects, including single-family homes, that create or replace 2,500 square feet or more of impervious surface. Implement LID Measures:
- Limit disturbance of natural drainage features.
- Limit clearing, grading, and soil compaction.
- Minimize impervious surfaces.
- Minimize runoff by dispersing runoff to landscape or using permeable pavements
- Application completeness:
- Submit a Stormwater Control Plan for Small (Tier 1) - Projects (Single Family Residence Site Plan).
Tier 2: Projects, other than single-family homes, that create or replace 5,000 SF or more of net impervious surface*

Detached single-family homes that create or replace 15,000 SF of or more net impervious surface*.
Tier 1 requirements, plus: Treat runoff with an approved and appropriately sized LID treatment system prior to discharge from the site.

Application completeness: Submit a Stormwater Control Plan that addresses Site Design (Tier 1), runoff treatment and source control measures (Tier 2).
Tier 3: Projects including single-family homes that create or replace 15,000 SF or more of impervious surface. Tier 2 requirements, plus: Prevent offsite discharge from events up to the 95th percentile rainfall event using Stormwater Control Measures.

Application completeness: Submit a Stormwater Control Plan that addresses Site Design (Tier 1, runoff treatment and source control measures (Tier 2), and stormwater retention (Tier 3).
Tier 4: Projects that create or replace 22,500 SF or more of impervious surface (collectively over the entire project site). Tier 3 requirements, plus: Post-development peak flows discharged from the site must not exceed pre-project peak flows for 2-year through 10-year storm events.

This requirement is not applicable in Watershed Management Zone 4 (on the west side of Paso Robles).

*Net impervious surface equals new and replaced impervious area minus the total pre-project-to-post-project reduction in impervious area (if any).