Tucson, Arizona, with its arid climate and limited annual rainfall, presents unique challenges and opportunities for water harvesting. Efficient collection, storage, and distribution of water can significantly reduce reliance on municipal supplies, improve plant health, and contribute to sustainable gardening and landscaping practices. Additionally, integrating fire-resistant plants into landscapes enhances safety by reducing the spread of wildfires, a growing concern in dry desert environments.
This guide provides an in-depth look at water harvesting techniques, best practices, fire mitigation strategies, and implementation approaches specifically suited for Tucson’s environment.
Why Harvest Water in Tucson?
Water harvesting provides numerous benefits, including:
- Reducing dependence on municipal water: Conserving potable water by utilizing rainwater for irrigation.
- Lowering water bills: Less need for paid water sources results in cost savings.
- Supporting desert-adapted plants: Rainwater is free of salts and chemicals found in treated water, making it ideal for native and adapted species.
- Preventing urban flooding: Capturing runoff mitigates erosion and flooding during monsoon season.
- Enhancing soil moisture: Proper water distribution improves plant root health and soil structure.
- Mitigating fire risk: Properly designed landscapes with moisture-retaining plants can help reduce wildfire spread.
- Increasing property value: A well-designed water-efficient landscape is aesthetically pleasing and can enhance real estate value.
Types of Water Harvesting
Passive Water Harvesting
Passive water harvesting involves techniques that direct, slow, and absorb water without requiring mechanical intervention. These methods are particularly beneficial for landscaping, groundwater recharge, and erosion control.
- Contour Berms and Swales
- Berms are raised soil barriers, while swales are shallow ditches designed to capture and redirect water.
- These structures slow down water movement, allowing it to percolate into the soil.
- Ideal for directing rainfall to tree basins and garden beds, reducing the need for supplemental irrigation.
- Basins and Depressions
- Shallow basins collect rainwater and allow it to infiltrate slowly.
- These can be placed around trees, shrubs, and garden beds to provide deep watering during rainy periods.
- When lined with mulch or organic matter, they reduce evaporation and promote soil health.
- Permeable Paving
- Unlike traditional concrete, permeable paving allows rainwater to soak through the surface into the soil below.
- Reduces runoff and recharges groundwater supplies.
- Examples include gravel driveways, permeable concrete, and interlocking pavers with gaps.
- Curb Cuts and Street Runoff Collection
- Modifications to street curbs allow water from roads to flow into adjacent plant beds instead of draining into storm sewers.
- Helps sustain urban greenery and reduces water loss.
- Must be carefully designed to prevent pooling and mosquito breeding.
- Rain Gardens
- Shallow, planted depressions designed to capture and absorb rainwater from roofs, driveways, and streets.
- Filled with native plants and mulch to help filter pollutants and improve soil absorption.
- Aesthetic and functional, providing habitat for pollinators and improving biodiversity.
- Terracing
- The practice of cutting step-like levels into sloped land to slow down water runoff and enhance infiltration.
- Helps in controlling erosion on hilly terrain.
- Often used in combination with mulch and drought-tolerant plants to maximize benefits.
- Mulching and Soil Amendments
- Using organic mulch around plants reduces evaporation and increases soil moisture retention.
- Compost and other soil amendments improve soil structure, allowing better water absorption and storage.
- Promotes healthier plant growth by retaining nutrients and minimizing water loss.
Active Water Harvesting
Active water harvesting uses infrastructure to collect, store, and distribute water for later use. These methods require more initial investment but provide greater control over water use.
- Rain Barrels
- Small-scale storage containers that collect rainwater from rooftops.
- Typically hold 50–100 gallons and are ideal for watering small gardens.
- Equipped with a spigot for controlled water release and can be connected to drip irrigation.
- Cisterns
- Larger storage tanks that can hold hundreds to thousands of gallons.
- Available in above ground and underground models to store water for irrigation or household non-potable use.
- Equipped with pumps or gravity-fed systems for controlled distribution.
- Greywater Systems
- Reuse of water from sinks, showers, and laundry for irrigation.
- Requires plumbing modifications but significantly reduces freshwater consumption.
- Must comply with Arizona greywater regulations to ensure safety and proper implementation.
- Stormwater Collection Systems
- Large-scale systems designed to capture and store runoff from roads, parking lots, and large rooftops.
- Typically used in commercial or municipal settings to supplement irrigation and reduce flooding risks.
- Can be combined with filtration systems for enhanced water quality.
- Dew Collection Systems
- Innovative methods that extract moisture from the air, condensing it into usable water.
- Useful in extremely arid regions with limited rainfall.
- Can supplement other harvesting methods when humidity levels are sufficient.
Fire-Resistant Plants for Mitigating Fire Risks
To further enhance sustainability and safety, incorporating fire-resistant plants into landscapes can help slow the spread of wildfires and provide a safer buffer around homes and structures.
Characteristics of Fire-Resistant Plants
- High moisture content: Plants that retain water in their leaves and stems are less likely to ignite.
- Minimal resin or oil production: Avoid plants with high resin or oil content, as these materials burn more readily.
- Low-growing habit: Ground covers and low shrubs help reduce fire spread.
- Deciduous nature: Many fire-resistant trees and shrubs drop their leaves seasonally, reducing fuel load.
- Deep-rooted species: These help with soil stabilization and increase moisture retention.
Recommended Fire-Resistant Plants for Tucson
Trees:
- Desert Willow (Chilopsis linearis) – A drought-tolerant, deciduous tree with minimal leaf litter.
- Netleaf Hackberry (Celtis reticulata) – Provides shade with fire-resistant characteristics.
- Arizona Sycamore (Platanus wrightii) – A water-wise tree that thrives along washes and floodplains.
- Velvet Mesquite (Prosopis velutina) – A nitrogen-fixing native tree that supports local wildlife.
Shrubs:
- Creosote Bush (Larrea tridentata) – A native desert shrub with a high moisture content and minimal litter.
- Texas Sage (Leucophyllum frutescens) – Fire-resistant and drought-tolerant with attractive purple blooms.
- Saltbush (Atriplex canescens) – A hardy, low-maintenance shrub with a high moisture content.
- Jojoba (Simmondsia chinensis) – An evergreen shrub that requires little water and resists ignition.
- Chuparosa (Justicia californica) – A vibrant flowering shrub that provides nectar for hummingbirds.
Ground Covers and Perennials:
- Trailing Dalea (Dalea greggii) – A spreading ground cover with excellent erosion control properties.
- Deer Grass (Muhlenbergia rigens) – A clumping grass that stays green longer and resists ignition.
- Desert Marigold (Baileya multiradiata) – A low-growing perennial with fire-resistant properties.
- Globemallow (Sphaeralcea ambigua) – A colorful and hardy ground cover ideal for xeriscaping.
- Blackfoot Daisy (Melampodium leucanthum) – A low-maintenance perennial with long-lasting blooms.
- Firecracker Penstemon (Penstemon eatonii) – A bright red, hummingbird-attracting flower with fire-resistant characteristics.
By combining water harvesting techniques with fire-resistant landscaping, Tucson residents can create sustainable, resilient outdoor spaces that conserve water and enhance safety. Whether through passive earthworks, active storage systems, or strategic plant selection, these practices contribute to long-term environmental and economic benefits for the region. With available rebates and proper design, implementing these strategies is both practical and rewarding. Incorporating native and adapted plants further reduces maintenance and enhances biodiversity, making Tucson landscapes both beautiful and functional for years to come.