Houston, a city long defined by its gigantic live oak trees and lush landscaping, is changing for the worse as the relentless, thrashing sun has taken a toll on all things green and growing.

The ongoing drought, which is the worst in Houston’s 175-year history, destroyed the first wave of historic live oak trees this week in Memorial Park and throughout the city, Trees for Houston executive director Barry Ward tells CultureMap.

The once utopian backdrop of Memorial Park has been most affected by the outdoor water restrictions, leaving thousands of trees close to dead. Only approximately 400 of those have been removed, and Ward says a potential catastrophic wildfire could strike if the dead trees don’t get cleared out soon.

“If the timber isn’t removed and someone flicks a cigarette butt in the wrong place, 100 acres could be burned down in one day,” Ward says. “Could you imagine? A 100-acre wildfire inside the Loop?”

The city is, however, working quickly to remove as many trees as possible, with the ones that may harm people or property given priority.

Ward said the greater Houston region is home to more than 660 million trees, but even if rain were to fall today, 66 million of those trees will be dead and removed within the next 24 months.

“Most of the damage to the trees has already been done and their root structures have been destroyed,” Wards said. “We are trying to save as many trees as we can though, and the city is doing an unusually thorough job of trying to find where to best use their resources.”

The city has four watering trucks and a few more on contract making the rounds to try and keep trees hydrated. Trees for Houston has also shifted most of its planting money to contract watering trucks for the rest of the drought, and is heavily watering parts of Memorial Park, though Ward said it will never look the same.

A Houston Parks and Recreation Department rep said it is focusing on conserving the live oak trees that line Main Street, since the majority of them are more than 80 years old and hold great significance to Houstonians. If only two or three of those Main Street trees were to die, it would take almost a 100 years for the street to be architecturally sound again, Ward said.

Given the fact that more trees have been lost this summer than in Hurricane Ike (which uprooted thousands of trees), the drought of 2011 may go down in Houston history as the year the city turned brown.