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42 / BUILDING DIALOGUE / March 2022 ELEMENTS Landscape Design Building Great Communities in Midst of a Changing Climate W ater has become a critical devel- opment issue throughout much of the country. Builders and commu- nity developers are being impacted by issues of ongoing drought, aridification, water quality, storm-water management, and aging infrastruc- ture. These issues are influencing the pace and direction of building and housing affordability across the country. A more water-driven approach to neighborhood and community design can effec- tively address these challenges. Some 71% of the Earth’s surface is covered in wa- ter, yet only 3% of Earth’s water is fresh water and only 1% of this water is accessible. Only 0.007% of the planet’s water is available to fuel and feed its 6.8 bil- lion people. In the West, drought and long-term arid- ification mean there will be even less water accessi- ble and drinkable for a rapidly growing population. In the East and Southeast more intense storm events and increased rainfall mean increased flooding, prop- erty damage and contamination of potable water sources. The way you design and build your commu- nities has a dramatic effect on this demand for water. The cost and availability of potable water is not just a problem of the arid western U.S. Ever increas- ing demand for potable water as climate change re- duces availability is placing more pressure on old, inadequate facilities. In many communities in the South and East, increasing rainfall is exceeding the capacity of antiquated and undermaintained storm water infrastructure. Many older cites in the East are unraveling out-of-date combined storm and sanitary sewer systems that are being overwhelmed by ever increasing sewage and stormwater volumes. Increasing construction costs and resultant tap fee increases for both water and sanitary sewer are driv- ing up the cost of newdevelopment and significantly impactinghousingaffordability. Rainwater capture is a viable design approach even in moderate and high rainfall areas. Every gallon of rainwater captured and directed to landscape areas is a gallon of water a mu- nicipality does not have to accommodate in its water treatment and distribution infrastructure. The “urban heat island” effect, where impervious surfaces, heat generated by buildings, homes andmo- tor vehicles create a rise in temperature in the urban condition, is impacting cities in both high- and low- water environments. Green roofs, “complete streets,” parks, andopen spaces and innovativeurban forestry programs can be used to combat the effect and cool down our communities and neighborhoods. Green roofs also provide for improved water quality and can detain significant amounts of stormwater. Here is a top 10 list of things you can do today in the neighborhoods and communities you are build- ing to conserve water and use it more efficiently: • Use low-impact design principles for your devel- opment. • Preserve the native landscape. The native land- scape provides for ecological diversity, is regen- erative, performs best with natural rainfall, and provides significantly greater stormwater manage- ment benefit by holding and slowing run-off better than urbanized, non-native landscapes with more Craig Karns, ASLA, ULI, NAHB Principal and Founder, Con- silium Design Low-impact development at Leyden Rock in Arvada Parking lot street flow to water quality swale at Stanley Marketplace