Making the Most with Stormwater From each home and down to the - - PowerPoint PPT Presentation

Catlow Shipek

Policy and Technical Director

Kieran Sikdar, CFM

Engineer and Program Manager

Making the Most with Stormwater –

From each home and down to the San Pedro River

Watershed Management Group develops and implements community‐based solutions to ensure the long‐term prosperity of people and health of the

• environment. We provide people with the knowledge, skills, and resources for

sustainable livelihoods.

Developing an Action Plan

Purpose:

• Promote Health of San Pedro River
• Reduce groundwater demand
• Enhance recharge
• Promote Health of Community
• Economic prosperity
• Shade & beautify
• Reduce nuisance flooding

Stormwater Utilization Opportunities

Demand Reduction – Low Impact Development Practices Enhanced Recharge – Geomorphic Restoration Treatments Enhanced Urban Recharge – Direct Recharge Facility

Stormwater Utilization Opportunities

Demand Reduction – Low Impact Development Practices

WMG’s Living Lab and Learning Center

LID demonstrated @Cochise College

LID Demonstrated @McFadden Park

LID Demonstrated @ Sierra Vista City Hall

Potential LID Demonstration @ along Garden Ave

Fry Blvd Main Gate Entrance

Woodcutter Wash Hydrologic Modeling of LID Scenario

Scenario: 10% LID adoption

• f small scale

distributed features included retrofits of:

• residential

landscapes

• commercial

landscapes

• parking areas, and
• street rights‐of‐

way 4” ponding basin depth (assume no infiltration during rain event) 2 year, 6 hour rain

Woodcutter Wash Hydrologic Modeling of LID Scenario

Scenario: 10% LID adoption

• f small scale

distributed features included retrofits of:

• residential

landscapes

• commercial

landscapes

• parking areas, and
• street rights‐of‐

way 4” ponding basin depth (assume no infiltration during rain event) 2 year, 6 hour rain

Woodcutter Wash Hydrologic Modeling of LID Scenario

Scenario: 10% LID adoption

• f small scale

distributed features included retrofits of:

• residential

landscapes

• commercial

landscapes

• parking areas, and
• street rights‐of‐

way 4” ponding basin depth (assume no infiltration during rain event) 2 year, 6 hour rain

Cost Benefit Analysis (CBA)

Costs

Installation and maintenance

Benefits

Based on the volume of water harvested and the number of trees planted.

Benefit/Cost Ratio: Bigger is BETTER!

$3-6 Benefit / $1 Cost

Summary of LID policy opportunities

• Route stormwater to sunken landscape areas before

being discharged offsite.

• Retain the 15 minute 95% rainfall event on‐site (~0.5”)
• Infiltrate collected water within 24hrs
• Utilize and maintain vegetation, low‐water use native

plants, as a functional element of the stormwater harvesting system

• Water harvesting practices to meet on‐site irrigation

demand

• Develop funding mechanism for LID retrofits and

adoption incentives

Stormwater Utilization Opportunities

Demand Reduction – Low Impact Development Practices Enhanced Recharge – Geomorphic Restoration Treatments

Channel Erosion and Concept Design

• Analyze stability of the wash.
• Suggest methods for correcting

erosion problems.

• Evaluate opportunities for

managed groundwater recharge (MGR).

Grade Control and Erosion

• Analyze stability of the wash.
• Suggest methods for correcting

erosion problems.

• Evaluate opportunities for

managed groundwater recharge (MGR).

Design Concept to re‐route upland flows

• Analyze stability of the wash.
• Suggest methods for correcting

erosion problems.

• Evaluate opportunities for

managed groundwater recharge (MGR).

Image credit: Stream Dynamics Image credit: Stream Dynamics

Location: San Vicente Creek, Silver City, NM Built for a 100yr (8600cfs) event with a 1.5‐2 design safety factor

• Protects a sewer main
• Controls grade
• Promotes riparian

vegetation for long‐term natural stability

Image credit: Stream Dynamics

Natural Channel Design for Enhanced Recharge

• Identify areas with greater

permeability

• Use features that promote

streambed infiltration and bank storage

• Mimic channel bed slopes

and fluvial structure of stable reaches

• Tie projects to additional

community benefits: bike/pathways, protecting infrastructure, promoting riparian vegetation and wildlife,…

Stormwater Utilization Opportunities

Demand Reduction – Low Impact Development Practices Enhanced Recharge – Geomorphic Restoration Treatments Enhanced Urban Recharge – Direct Recharge Facility

Tackling the Water Deficit

Assumption - Three Scenario Timeframes (fixed, not variables in this model) Percentage

• f Supply

relative to current use (assumed) Population Growth Rate per year (assumed) Adoption by SV home of RWH and efficiency Change per year (Assumed) Sierra Vista GPCD Rate

• f Change

per year (assumed) Other Demand Change per year (assumed) Channel Portion Treated to Enhance Urban Stream Recharge for Sierra Vista (assumed) Phase 1: Early adopters 2015-2020 100% 0.0% 5.0%

• 6.0%
• 2.0%

10.0% Phase 2: Moderate adopters 2021-2025 100% 2.0% 10.0%

• 4.0%
• 2.0%

10.0% Phase 3: Majority adopted 2026-2030 100% 2.0% 10.0%

• 4.0%
• 2.0%

0.0% Fixed Parameters Demand Impacts on Deficit Sierra Vista Subwatershed MODEL PARAMETERS