How Outdoor landscapes are Critical to Our Cities Survival
A vital component of our cities, urban outdoor landscapes present a wealth of opportunity when it comes to water sustainability and climate resilience. Whether it’s outside a home, a store, or an office, a property’s primary interaction with the environment is it’s landscape.
Using sustainable landscape strategies, our urban outdoor areas can help our communities weather droughts, mitigate floods, sequester carbon, improve human well-being and much more.
Are Sustainable Landscapes the Answer to Urban Problems?
Can we use sustainable landscapes to actively contribute to our watershed’s health? Sustainable landscapes would theoretically help balance our local climate and ecology. The 4 key elements of sustainable landscapes include:
- Preserving and building healthy soils.
- Preserving vegetative cover growth.
- Using climate-appropriate plants.
- Conserving water and other resources.
Sustainable landscape strategies would include tactics such as removing turf, building rain gardens or installing permeable pavement or rain reservoirs.
How to Make Changes to Achieve Sustainable Urban Environments
California is a great example, and represents our problems nationally and globally. These should be examined more closely. California has always had a wide range of yearly precipitation levels and patterns. This appears to be increasing with climate change.
California is experiencing longer and more severe droughts, and more intense storms. There also seem to be more dramatic fluctuations between the extremes. This means that California cities are facing more severe threats of both water shortages and increased flooding.
Current urban landscapes, which are covered by big lawns and paved areas, don’t offer any relief from the problems of drought or flooding. In most cases, lawns and pavement exacerbate the problems.
Thirsty turf grass requires a lot of irrigation, especially when it’s dry and hot and water is in shorter supply. More than half of urban water use in California (PDF) goes to landscape irrigation. Vast expanses of pavement leave no place for rain water to go but down the drain. Limited capacity to handle intense storms is the leading cause of flooding and the spreading of pollution.
Are There Better Sustainability Options for Our Cities?
We have an opportunity to transform our urban landscapes into assets for climate resilience, rather than a source of risk. We can replace water hungry lawns with native plant landscaping and reap significant rewards.
Studies of both types of landscapes showed that the sustainable landscape uses 83 percent less water. It also creates 56 percent less green waste and requires 68 percent less maintenance than the more traditional lawn based landscaping.
Sustainable landscapes provide a multitude of benefits (PDF), however here we’ll focus on four themes here: how sustainable landscapes affect community; flood; drought; and carbon.
Sustainable landscapes improve community well-being
Sustainable landscapes provide benefits to communities, beyond helping them weather droughts and floods. Switching from outdoor areas dominated by grass and pavement to ones with beautiful native plants and expanded natural spaces improves our well-being.
Research shows that employees who have access to sustainable landscapes at their workplace are happier and more productive. Adopting sustainable landscape practices alleviates the urban heat island effect, a public health threat growing worse because of climate change.
How Sustainable Landscapes Reduce Flooding and Water Pollution
California is experiencing more rain events that are growing in intensity. Urban areas need to better prepare for these storms, and improve their flood management. Sustainable landscapes are better at capturing and holding water. This is also useful for mitigating local flooding.
If water is absorbed into the soil, that means less water pooling on streets, parking lots and sidewalks. The following changes would contribute to reducing localized flooding:
- Designing existing green spaces to hold flood waters.
- Reducing the amount of paved area.
- Replacing paving with permeable paving or more green space.
These strategies would also help prevent water pollution in our waterways. Sustainable landscapes can absorb and purify the “first flush” of a rain event. This which contains the most polluted water carrying all the grime and contaminants from our city streets.
Sustainable Landscapes Must be Drought Resistant
There are two key ways that sustainable landscapes can make urban communities more resilient to drought: using less water, and capturing water to use later.
Replacing grass with climate appropriate plants and properly irrigating those plants can reduce a landscape’s water needs by 70-80 percent. Changes made during the last California drought were clearly evident on Google Maps. As a result of these changes California’s urban communities were able to exceed the emergency drought mandate of reducing water use by 20 percent.
Sustainable landscapes can be designed to capture water and hold it for future use. Building healthy soils allows water not taken up by plants to infiltrate down into groundwater aquifers, rather than running off and being lost down the drain.
Rain barrels and tanks can capture roof runoff, which can be applied back onto the landscape when it’s needed. Research shows that applying these approaches across southern California and the San Francisco Bay Area could increase local water supplies (PDF) by 20 billion gallons each year, roughly the amount of water used by the city of Los Angeles annually.
Sustainable Landscapes Sequester Carbon and Reduce Greenhouse Gas Emissions
Water, energy and land use management are all intertwined and deeply connected to climate. Healthy soils rich in organic matter, a key component of sustainable landscapes, can provide carbon mitigation by sequestering carbon from the atmosphere.
Sustainable landscape practices also can reduce energy use because they require less mowing, blowing and green waste hauling than typical grass-dominated landscapes. There is also the energy embedded in water (PDF) to consider. With sustainable landscaping using native plants instead of sod, which means less water needs to be collected, treated and transported to irrigate your landscape.
How Innovation Will Help Us Transition to Sustainable Urban Landscapes
The challenge of achieving resilience to droughts and floods, reducing carbon emissions and fostering community well-being is one faced by cities around the globe. These are important and deeply connected issues with urban landscapes at the center of them all.
With urbanization increasing, and climate change becoming a growing issue, the call to action is becoming more urgent. Tackling this requires the collaboration of diverse urban stakeholders, from residents, businesses, scientists, city governments and on-the-ground change makers. The Pacific Institute has been working for over 30 years on advancing innovative solutions for water-smart cities, including sustainable urban landscapes.
How have you adapted your urban landscape to promote Sustainability? Share your urban landscaping success with us in the comments.
Calculate Your Carbon Footprint
If you would like to calculate your Carbon Footprint, follow the link to the free carbon footprint calculator of the United States Environmental Protection Agency.