Central Coast Joint Effort for LID and Hydromodification Control

The Joint Effort is a collaborative, region-wide approach municipalities are using to implement Low Impact Development and Hydromodification Control. The Storm Water Management Programs (SWMPs) for each municipality participating in the Joint Effort contain specific Best Management Practices (BMPs) pertaining to the Joint Effort. These BMPs fall into two categories: development of hydromodification control criteria, and implementation of hydromodification controls and LID. Below are links to information on these two categories as well as additional information about the Joint Effort.

• Brochure: The Central Coast Joint Effort for Controlling Impacts of Urban Growth
• Questions and Answers on the Joint Effort

April 8, 2013 Public Comment Documents for Draft Resolution R3-2013-0032 Approving Post-Construction Stormwater Management Requirements for Development Projects in the Central Coast Region

1. Public Notice
2. Description of Proposed Changes to Post-Construction Requirements
3. Draft Resolution No. R3-2013-0032 (tracked changes version)
4. Attachment 1: Post-Construction Requirements (tracked changes version)
5. Attachment 2: Technical Support Document (tracked changes version)

Technical Support Document, Attachment A: Watershed Management Zone Maps (8.6 MB)
Technical Support Document, Attachment D: Case Study of Hydrologic Benefits of On-Site Retention in the Central Coast Region
Technical Support Document, Attachment E: Methods and Findings of the Joint Effort for Hydromodification Control in the Central Coast Region (2.8MB)
Technical Support Document, Attachment G: Stormwater Control Measure Sizing: Evaluation of Attachment D to the Central Coast Post-Construction Requirements

6. Draft Resolution No. R3-2013-0032 (changes accepted version)

Attachment 1: Post-Construction Requirements
Attachment 2: Technical Support Document

 

Resolution R3-2012-0025 Approving Post-Construction Stormwater Management Requirements for Development Projects in the Central Coast Region

• Resolution R3-2012-0025
• Post-Construction Stormwater Management Requirements for Development Projects in the Central Coast Region
• Technical Support Document

September 6, 2012 Draft Post-Construction Requirements Available for Public Comment

Staff Report

Staff Report Attachments:

1. Resolution No. R3-2012-0025 (track changes version)

Resolution, Attachment 1: Post-Construction Requirements (track changes version)
Resolution, Attachment 2: Technical Support Document for Post-Construction Requirements (track changes version)


Technical Support Document, Attachment A: Watershed Management Zone Maps (8.6MB)
Technical Support Document, Attachment D: Case Study of Hydrologic Benefits of On-Site Retention in the Central Coast Region
Technical Support Document, Attachment E: Methods and Findings of the Joint Effort for Hydromodification Control in the Central Coast Region (2.79MB)

2. Post-Construction Requirements (track changes accepted)
3. Public Comment Letters Received on May 14, 2012 Draft Resolution
4. Public Comments Received on May 14, 2012 Draft Resolution and Central Coast Water Board Staff Responses
5. Key Issues in Public Comments on May 14, 2012 Draft Resolution and Central Coast Water Board Staff Responses
6. Key Milestones and History of the Central Coast Joint Effort

85th and 95th Percentile Rainfall Depths

The Central Coast Post-Construction Requirements stipulate that municipalities must require Regulated Projects to use rainfall statistics provided by the Central Coast Water Board or to calculate site-specific rainfall depths determined from local rainfall data using USEPA’s methodology (see Post-Construction Requirements Provision B.4.c). 

Rainfall Statistics Provided by the Central Coast Water Board:

WARNING: Read instructions before downloading maps.
85th Percentile Rainfall Depth Maps (Adobe Reader, pdf)
95th Percentile Rainfall Depth Maps (Adobe Reader, pdf)

Shapefiles of 85th and 95th Percentile Rainfall Depth Maps (GIS Shape Files)

Memo Explaining Process for Developing Rainfall Depth Maps
Memo Documenting Confidence Interval Accuracy of Rainfall Depths


Directions for Using Local Rainfall Data to Develop Site-Specific Rainfall Depths:
Directions for Using Local Rainfall Data to Develop Site-Specific Rainfall Depths

Spatial Data Coverages

Shapefile Descriptions

The following spatial data coverages are available, grouped by County:
Watershed Management Zones
Physical Landscape Zones
Receiving Water Type
Groundwater Basins
Geology
Urban Nodes
Hydrologic Soil Groups

Download these coverages by clicking on the County name below. 
NOTE: Download times may be lengthy, depending on connection speeds; GIS Software is required to open files once downloaded to your computer system.

Santa Cruz County (13 MB)
Santa Clara County (6.8 MB)
San Benito County (15.7 MB)
Monterey County (36 MB)
San Luis Obispo County (57.9 MB)
Santa Barbara County (32.8 MB)

Development of Hydromodification Control Criteria: Phase 1

Project Background

Fact Sheet: Why Control Hydromodification?

Methodology Project Deliverables

Review of Existing Data
Literature Review
Watershed Characterization Part 1: Precipitation and Landscape
Watershed Characterization Part 2: Watershed Management Zones and Receiving Water Conditions
Linkage Analysis: Landscape Characterization, Receiving Water Conditions, Watershed Processes, and Human Disturbance

Implementation of Hydromodification Controls and LID

To Support Integration of Post-Construction Requirements into Municipal Requirements:

User Guide for Municipal Implementation (PDF)
User Guide for Municipal Implementation (MS Word)
User Guide for Municipal Implementation – Flow Charts (MS PowerPoint)

To Support Integration of LID as Part of New and Redevelopment Projects:

LID Design (slideshow)
Steps for Successful LID Design
LID Frequently Asked Questions (FAQ)

To Support Local Regulatory Updates for Hydromodification in New and Redevelopment:

Municipal Regulatory Update Training: AHBL Leads LID Webinar for Municipal Regulatory Update Assistance Program (MRUAP) for California's Central Coast Jurisdictions AHBL's Wayne Carlson, AICP worked with Darla Inglis, Ph.D. of the UC Davis Low Impact Development Initiative to host a webinar training series for the MRUAP. The purpose of the training was to aid local governments with the review, revision, and presentation of new and amended regulatory language for hydromodification control and LID to elected officials for adoption as required by the Phase II NPDES Permit. To view the PowerPoint presentations used in the on-line MRUAP training, please click the links below:

MRUAP Session One
MRUAP Session Two

To download the PowerPoint and webinar video files, please visit AHBL's FTP site. To login using the following account (note, both the Username and Password are case sensitive).

Username: MRUAP
Password: MRUAP!

Hydromodification Control and LID Gap Analysis Template - Tacoma
Hydromodification Control and LID Gap Analysis Template - Tacoma Excel Table
Hydromodification Control and LID Gap Analysis Template - Generic
LID Site Analysis Requirements – sample language
LID Maintenance Agreements – sample language
City Council Support Documents

To Provide Technical Support for LID Implementation:
LID Parking Lot Technical Assistance Memorandum (TAM)
LID Bioretention Vegetation Guidance TAM

Additional Internet Resources:

CASQA’s Low Impact Development Portal
Volume-Based Hydrology – Examining the shift in focus from peak flows and pollution treatment to mimicking predevelopment volumes (Stormwater magazine)
Achieving Sustainable Site Design through LID Practices, by Anne Guilette

Regional Project Examples:

City of Paso Robles 21st Green Street
City of Atascadero Zoo Green Parking Lot