04/21/2014 11:02 am ET Updated Jun 21, 2014

Taking the Long View of the National Mall on Earth Day

Earth Day 2014's theme, Green Cities, is particularly appropriate as we consider the challenges and opportunities of the iconic landscape that is the centerpiece of our Capital City -- the National Mall.

The National Mall is a unique national park -- a living memorial to American ideals in the heart of an urban setting, where more than 29 million people from around the world visit each year. That's more visitors than Yosemite, the Grand Canyon, and Yellowstone National Park combined.

When Pierre L'Enfant conceived the Mall in 1791, and when it began to take its current form in the early 1900s with the McMillan Plan, no one could have imagined the volume of visitors or the thousands of rallies, concerts, and events that would take place each year.

The result? The National Mall has been loved to death, and the evidence is all around -- the grassy vista stretching from the Lincoln Memorial to the Capitol Building has been turned into a dustbowl of dirt and rock solid turf. Sidewalks are cracked and broken. The walkways around the Tidal Basin near the Jefferson and Roosevelt Memorials are slowly sinking. Fish die each August in the Constitution Gardens pond.

So when the National Park Service decided eight years ago to embark on a comprehensive plan for the future of National Mall, it set out to tackle $400 million in much-needed repairs, and took the opportunity to make this urban park more "green" and functional for generations to come. This National Mall Plan, signed into effect in 2010, provides a critical blueprint for a more sustainable and visitor-friendly urban park.

To date, the National Park Service, with the support of the Trust for the National Mall, has repaired the Lincoln Memorial Reflecting Pool, preserving approximately 50 million gallons of city drinking water that leaked every year, and replaced the source with water from the nearby Tidal Basin.

Energy-efficient LED lights were installed along pathways from 3rd to 14th Streets, reducing the Mall's lighting energy use by an estimated 65 percent. And a recycling program supported by The Coca-Cola Company placed over 300 permanent blue recycling bins in high-traffic areas throughout the park, enabling the Park Service to process about 17 tons of recyclable material each month.

The Trust for the National Mall, through a national design competition, has major plans for habitat and soil restoration, low-maintenance landscaping, energy-efficient infrastructure, and water conservation in poorly-functioning areas of the park near Constitution Gardens and the Sylvan Theater. Complete with amenities like a skating rink and an outdoor amphitheater, these areas will highlight how the park can be sustainable, while being enjoyed and stewarded by the visitors it serves.

The project that has done more to "green" the Mall than any other thus far is the ongoing restoration of the park's rock-hard, compacted grass. It is also the project that is most dependent on a public commitment to sustainability.

The National Park Service sought out turf experts - many from major league sports stadiums -- who helped choose durable strains of seed and compaction-resistant soil. The park built a drainage and irrigation system that uses cisterns to capture and hold rain and gray water for watering the grass -- making the new lawn green in every sense of the word.

These efforts are just one half of an equation to make the National Mall more sustainable. The other half falls on the millions of visitors, event planners, and protesters to not only enjoy -- but to also protect -- this national treasure. Leave no trace is an ethos that pervades society's thinking about the great outdoors, and we need to extend that thinking to urban landscapes like the National Mall.

Taking care of our natural resources, and one as important as the National Mall, requires all of us to come together to preserve it for each other, and future generations to enjoy.

The great news is many visitors are showing the park to be a laboratory of how people and nature can peacefully coexist. At President Obama's second inauguration, the National Park Service and the inaugural committee put down a layer of permeable plastic widely used in sporting arenas to protect the newly refurbished areas of the National Mall lawn. The intervention protected the grass while inauguration visitors enjoyed the event.

On a smaller scale, the congressional softball teams -- several hundred members strong -- continue to play their games on the National Mall, yet now they are rotating home plate to minimize wear and tear on the new grass. They are among the newest stewards of a refurbished National Mall.

The National Mall is free and open for all visitors, and it requires a new mindset to make it a sustainable national park that can be affordably preserved for our children and grandchildren. It isn't just about marble, granite and grass. Ultimately, how we treat the National Mall says a lot about our belief in the most iconic common ground in America, and the values it represents.