WATER

Water is a precious resource, and natural systems are of critical value for their ability to store, clean and distribute available water.

WHY IS WATER MANAGEMENT IMPORTANT?

The shortage of clean water is rapidly becoming one of the most urgent challenges facing humanity. Only .003 percent of the earth’s water is available for human consumption. In the U.S. alone, 36 of 50 states anticipate a shortage in freshwater within the next 10 years. Our home lawns and gardens are a significant cause of this. Americans apply more than 7 billion gallons of water a day to landscapes, often in the form of potable water, or drinking water, without realizing the costs of treating and transporting this water source. Moreover, stormwater, or precipitation runoff, is often viewed as a waste product and is removed from the landscape as quickly as possible. Instead of capturing and using stormwater in our gardens and landscapes, this resource flows through a costly infrastructure of gutters, downspouts and sewers, often carrying with it residue from fertilizers, pesticides and other pollutants that can contaminate local waterways like creeks, lakes or rivers, and must be treated before returning back to the landscape in the form of irrigation water.

Learning specific water reuse and conservation strategies, gardeners can utilize stormwater and other non-potable water sources (e.g., air conditioner condensate) to irrigate their garden or landscape. Sustainable gardens capture these resources, store them on-site and reuse them in the landscape. Doing so saves money and protects nearby ecosystems from harmful pollutants. In addition, the amount of water going to storm sewer systems is reduced, lessening the likelihood of flooding and combined sewer overflows.

This water feature conserves rainwater. As water runs off the roof, it moves through a gravel bioswale into a small pond. Stepping stones and porous pavers reduce the area of impervious surface and slow runoff. Image credit: SWT Design

Lawns are unsustainable water hogs and sprinklers like this one waste water. Drip irrigation and diverse plantings are more sustainable options. Image credit: Shutterstock/Repina Valeriya

Rainwater captured in a plastic barrel. Image credit: Shutterstock/Egorov Igor

THE ROLE OF WATER IN A SUSTAINABLE LANDSCAPE

Water supports our environment and sustains our lives. It is required for producing food, clothing and electronics; transporting our waste; and supporting the natural environment. The effects of climate change vary regionally, but sustainable water management and low impact development strategies can provide adaptive benefits for a wide array of circumstances.

Conserving water reduces cost for irrigation.
Storing stormwater reduces runoff and lessens the amount of water that contributes to flooding.
Reusing captured stormwater reduces the need for irrigation via potable water.
Harvesting water from non-potable sources like air conditioner condensate or greywater minimizes dependency on potable water use.

MORE ON WATER

Water is a precious resource, and natural systems are of critical value for their ability to store, clean and distribute available water. Gardeners can help protect this resource by conserving water, preventing pollution, and building best practices into the design and everyday maintenance of a home’s landscape.

Additionally, water in a landscape can provide opportunities for restorative experiences and reflection. Such activities may promote healing, stress reduction and work productivity. The benefits people derive from having a stronger physical and mental connection to water and its sources are innumerable.

Water use is also apparent in many of our local community resources, such as fire-fighting, maintaining local parks or filling municipal swimming pools. However, communities all across the country are starting to face challenges regarding the supply and availability of water for these local services.

Using water wisely and efficiently, as well as planning creative and restorative uses for water in the landscape, will address the importance of restoring and maintaining natural water sources and systems, and will allow people to have a stronger mental and physical connection to water and the local climate.

The sights and sounds of water features in a garden can reduce stress. Image credit: Shutterstock/Moomusician

The infiltration and runoff of rainwater is directly influenced by the amount of impervious surface in an area. Image credit: Landscape For Life

Animal waste contributes to water pollution and must be disposed of properly. Image credit: Shutterstock/kkkomgri

Driveways covered with materials such as crushed seashells or locally sourced gravel are far more sustainable than those topped with coal tar sealants. Image credit: Shutterstock/jocic

LANDSCAPE PRACTICES CONTRIBUTE TO WATER POLLUTION

In a natural landscape, soil and vegetation hold onto and work to clean rain and stormwater. In developed areas, however, much of the land has been paved over, and the soil itself is often compacted and impervious. Rainfall flows from our roofs into gutters and downspouts, over compacted lawns and driveways, onto roads, and down storm drains — picking up pollutants all along the way. Researchers have found runoff from developed land to be the leading cause of water pollution in urban areas. In many older cities, stormwater can overwhelm sanitary sewers, sending raw sewage as well as runoff into nearby waterways.

Common sources of stormwater pollution:

Fertilizers, Herbicides and Insecticides

Excess nutrients from overuse of fertilizer can cause algal blooms when fertilizer runs off as part of stormwater. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can’t exist in water with low dissolved-oxygen levels. Insecticides and herbicides present in stormwater can poison aquatic life, while land animals and people can become sick from eating contaminated fish and shellfish or drinking pesticide-contaminated water. Homeowners can reduce the risk of these pollutants by minimizing their use of fertilizers and pesticides. Any excess fertilizer spread on driveways, sidewalks, streets or other impervious surfaces should be collected and properly disposed of before it has an opportunity to pollute stormwater.

Animal Waste

Feces contains bacteria and other matter that pollutes our waterways and can harm human health. Animal waste should be removed from vegetative areas surrounding waterways or other areas where it may contaminate stormwater runoff.

Rock Salt

Rock salt can leach into soil, changing its chemical composition, and it can poison fish and aquatic organisms after flowing into local waterways as part of stormwater runoff. It is also harmful to sensitive plants. Salt is highly corrosive to paved surfaces, buildings and metal. Alternatives to rock salt include materials that increase traction, such as kitty litter and sand. For situations where a product that actually melts ice is required, look for rock salt substitutes such as those made with beet juice extracts, a byproduct of beet sugar production that would normally be disposed of as waste. Magnesium chloride, which is safer to use near plants than rock salt (but not as effective in very cold conditions) is another possibility.

Fluids From Automobiles

Automobiles deposit pollutants such as oil and gas as well as particles from brake linings, tires and engines onto paved surfaces. These pollutants are washed off by rainfall and transported into storm sewers, often ending up in local waterways. Landscapes that capture and reuse stormwater minimize the spread of pollutants and provide a valuable water source to the garden.

Sediment

Sediment from improperly managed landscapes can cloud waterways and carry pollutants. Landscapes can minimize sediment pollution by preventing erosion and capturing stormwater and sediments on-site.

Building Materials

Materials such as copper and zinc found in roofing and gutters, along with galvanized materials and treated lumber, can contaminate stormwater. When replacing roofs, homeowners should consider materials such as wood or slate that typically release fewer pollutants. Green roofs are also an attractive option for buildings that can support the additional weight.

Coal Tar Sealants

Roads treated wtih coal tar sealants, or blacktop, contribute to the pollution of many urban lakes. This shiny black material, which is applied to driveways as well as roads, is high in polycyclic aromatic hydrocarbons (PAHs), which are toxic to aquatic life. Several PAHs are suspected carcinogens, and blacktop is also impermeable. Sustainable landscapes use less-toxic materials such as crushed seashells, which would otherwise be disposed of as a waste, or locally obtained gravel.

FRESHWATER SHORTAGES

What are the global and local impacts of freshwater shortages?

Freshwater supports our environment and sustains our lives. It is essential to human survival, our livelihoods and almost every form of economic production. This finite resource is required for producing food, clothing and electronics; transporting waste; and supporting the natural environment.

These landscape practices contribute to freshwater shortages:

Planting species not suited to local rainfall patterns
Wasteful irrigation practices
Degraded soil conditions that limit the infiltration and water-holding capacity of the soil
Paving, roofing and other impervious surfaces that prevent water from infiltrating the soil and recharging groundwater supplies
Treating stormwater as waste and funneling it to sewers before it has an opportunity to benefit the landscape.

Freshwater is a finite resource. Even seemingly small problems like a leaking faucet must be taken seriously and repaired. Image credit: Shutterstock/kwanhom

Unsustainable vs. Sustainable Landscapes:
How They Compare

Unsustainable Landscape

Treats stormwater as a waste product that is quickly removed from the site, contributing to water pollution.
Most irrigation systems use municipal drinking water.

Sustainable Landscape

Manages stormwater on site. Uses stormwater as a resource to sustain the landscape.
Minimizes the use of potable water. Supplements water in the landscape with on-site alternatives such as harvested rainwater, stormwater or air conditioner condensate.

GET STARTED WITH WATER

Create a Water-thrifty Landscape

Use Alternatives to Municipal Drinking Water for Irrigation

Use Plants Adapted to Local Rainfall Patterns

Limit Exposure to Pesticides

Protect and Restore Vegetated Buffers

Create a Rain Garden

Avoid Polluting Water Resources

BECOME A LANDSCAPE FOR LIFE TEACHER!

Landscape For Life includes a complete kit of teaching resources which can be used to conduct classes in sustainable home gardening. New training opportunities coming in 2023!

Learn More

Landscape For Life™ is a collaboration between Colorado State University Extension and the United States Botanic Garden based on the principles of the Sustainable Sites Initiative (SITES®).