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Green Infrastructure

  1. ‘Green Infrastructure for Regional Vibrancy’ Resolution
  2. Green Infrastructure Prioritization Tool
  3. Local GI/LID Benefits
  4. GI/LID Outreach
  5. Inventory of GI/LID Efforts within Pima County
  6. LID Case Studies Inventory Map
  7. Rainwater Harvesting
  8. Habitat Resource Planning
  9. Habitat and Species Protection

Our community leads the way for arid regions in innovative stormwater solutions. In a recent U.S. Environmental Protection Agenday document entitled, “Green Infrastructure (GI) in Arid and Semi-Arid Climates,” the Tucson region was used as an example several times as a growing Low Impact Development (LID) community which uses engineering techniques to mimic natural processes that retain and use stormwater while addressing pollution concerns.

Stormwater management efforts connect with the GI/LID approach through the best management practice of rainwater harvesting including green roofs, permeable materials, alternative street and building design, trees and rain gardens. The EPA has found that in most cases implementing well-chosen LID practices saves money for developers, property owners, and communities while protecting and restoring water quality.

Rainwater harvesting keeps yard chemicals on site, treating pollutants in runoff biologically through soil processes and slows flood flows which otherwise would be conveyed through the streets and into our fragile desert washes. Rainwater harvesting provides the additional benefits of storing water in the soil for vegetation, providing habitat, reducing the urban heat island effect, cooling and shading urban neighborhoods and improving air quality.

Promoting GI/LID practices is a great way to build stormwater quality awareness while actively conserving water in arid lands.

 Our watershed approach: Article in Edible Baja Arizona magazine

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‘Green Infrastructure for Regional Vibrancy’ Resolution

PAG created a resolution highlighting the economic, health and transportation safety benefits of Green Infrastructure (GI) and re-affirming the importance of using stormwater as a water resource for our region. A task force suggested the creation of the resolution comprised of support from jurisdictions across the region, Working Group members, and representatives from various fields of expertise representing each issue.

The resolution encourages incorporating green infrastructure as a cost saving option for roadway projects with greater return on investment than grey infrastructure.  It encourages sample guidance and policy and also recommends gathering testimonials and measuring how green infrastructure projects benefit our economic vitality, long-term water reliability, heat and drought resilience, urban biodiversity and ecosystem connectivity. 

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Green Infrastructure Prioritization Tool

Identify your heat vulnerability and tree shade opportunities through PAG's interactive web map:

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Local GI/LID Benefits

Green Infrastructure/Low Impact Development (GI/LID) are key design strategies that will allow our region to build value-added community benefit into upcoming infrastructure projects.  Understanding the economics for the full life cycle of a project is as important as understanding the planning and technical mechanics of GI/LID stormwater/water infrastructure design solutions.  This cost-benefit report, tailored with data specific to the arid southwest, is a tool to evaluate the spending of public funds for GI/LID solutions and account for social and environmental benefits.

In this project, PAG, Pima County Regional Flood Control District and the City of Tucson  worked with Impact Infrastructure, LLC  and Stantec in 2013 and 2014 on the the beta-stage of test of the automated business case evaluator of stormwater infrastructure called AutoCASE TM.

Additional project results for Sustainable Return on Investment (SROI) research and calculation resources:

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GI/LID Outreach

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GI/LID Efforts within Pima County
To gain an understanding of how the jurisdictions within the PAG region are implementing green stormwater infrastructure policies and programs, a wide-ranging analysis was undertaken in the summer of 2012. Using a rather inclusive definition of GI/LID, over 70 policies, programs, and other efforts were documented.  This exercise showed that municipal support of GI/LID has increased steadily since 1985.


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LID Case Studies Inventory Map


Pima County Regional Flood Control District and the Low Impact Development Working Group created a regional inventory of award winning case study sites and the Low Impact Development Case Study Map, which demonstrate excellence in designs that heal the watershed. Also, view the case study key and additionally the Inventory Site Addresses.

The LID Case Studies Map can be viewed on mobile devices via Avenza PDF Maps, by following the below steps.

1. Download the free App

Download PDF Maps on the App StoreAndroid app on Google Play

2. Copy URL:
3. Open PDF Maps app and go to Maps. Click on “+" to import map
4. Paste URL to “From the Web” to import LID Case Studies Inventory Map. Enjoy!

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Rainwater Harvesting

Rainwater harvesting, a stormwater management practice, captures or slows down surface stormwater so that it can be put to beneficial use.

When we harvest rainwater, we can use it to irrigate surrounding vegetation to help beautify the landscape and increase shade without depending on groundwater.

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Habitat Resource Planning

Water resources in the PAG region include groundwater, Central Arizona Project water, surface water, reclaimed water (effluent reuse) and stormwater. The region depends on water to sustain urban, agricultural and mining interests as well as natural habitat. 

PAG’s Watershed Program coordinates with local governments to discuss concerns and works to effect change at the state level as needed.

The Tucson region places a priority on preserving important habitat, wildlife corridors and critical linkages while continuing to grow and meet development demands. Pima County recently developed a long-term vision for protecting the region's heritage and natural resources through its Sonoran Desert Conservation Plan. Critical Habitat, biological corridors and riparian protection were some of the main features evaluated as part of this study.

Both the Town of Marana and the City of Tucson are working on their respective Habitat Conservation Plans, which propose conservation measures to aid the preservation needs of specific species. This work has been conducted in response to listings or potential listings of species under the Endangered Species Act.

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