WASHINGTON, D.C. -- Spring has sprung in our nation’s capital. Proof of the season’s arrival can be seen on thousands of cherry trees during peak bloom this week. 

It is perhaps the greatest indication that spring has arrived. 

“The blossoming with the cherry trees every year is arguably the grandest of springtime traditions in the nation's capital,” said Mike Litterst, the Chief of Communications for the National Mall and Memorial Parks. 

It’s peak bloom for roughly 3,700 cherry trees in Washington, D.C. that attract over one million tourists each year. 

“We can expect between a million and a million and a half people here during the four weeks of the National Cherry Blossom Festival,” said Litterst. 

It’s a tradition that Litterst and the National Park Service (NPS) are very familiar with, and a tradition that dates back to 1912. 

“The cherry trees were a gift from the mayor of Tokyo to the people of Washington, D.C. in 1912,” said Litterst. “It is arguably one of the oldest and most famous international gifts of friendship in the United States.” 

But preserving special traditions can be challenging, especially with environmental changes like rising water levels and an aging seawall dating back to the late 19th century. 

“So we've now got water six feet above where the walls were designed and originally constructed to keep it out,” said Litterst. “It’s causing considerable damage to cherry trees in the area, infrastructure in terms of sidewalks and walkways.” 

Within the next month, Litterst says a $113 million, three-year plan will get underway to reconstruct the seawalls near the Tidal Basin. 

140 cherry trees will be removed for the project, but Litterst says they'll still play a vital role in this treasured ecosystem. 

“They’ll be mulched, the mulch is returned to the National Mall. It's placed over pieces of trees to protect tree roots. And as the mulch breaks down, it becomes soil. And that soil provides nutrients for living trees for years to come,” said Litterst. 

Litterst says the short-term impact is necessary for the long-term benefit of enjoying this springtime tradition for the next century. More than 270 trees will be replaced near the Tidal Basin when the seawall construction is completed in 2027.