凱帝草原含有孕育數千隻鵝、鴨、蒼鷺、白鷺、鳴禽及其他野生動物的農田溼地、凹窪地貌溼地(depressional wetlands)、河道與沿海草原棲地。山巒協會同時也發現草原像個巨大的防洪海綿塊，吸收並防止洪水對下游水牛河區 (Buffalo Bayou)造成破壞。
然而3月3日德州運輸部(Texas Department of Transportation)利用聯邦經濟振興基金中的10億8千1百萬元投資包含此大公園路E段道路開發等方案。本項決定受到爭議，部分是因為決議尚未全數通過如工兵處(U.S Army Corps of Engineers)的環境協議。
The Sierra Club late Monday filed a lawsuit in federal district court in Houston against the Federal Highway Administration over the environmental impacts of the proposed Grand Parkway Segment E in western Harris County.
"In the rush to push Segment E of the Grand Parkway for the benefit of real estate developers, the Federal Highway Administration conducted a weak environmental review that ignores the project's harm to the Katy Prairie, its potential impact on Houston air quality, and better transportation alternatives. The Sierra Club, over the past 25 years, has worked to protect the Katy Prairie and implement transportation alternatives to the proposed Grand Parkway, Segment E. We are now at a point where we did not want to be.
Filing a lawsuit is a serious undertaking which requires money, time, and other resources. It is a strategy of last resort, not first resort. It is because the Sierra Club feels so strongly about protection of the Katy Prairie and the harmful effects the proposed Grand Parkway Segment E will have on the Katy Prairie, that we have filed this lawsuit," said Brandt Mannchen, air quality chair for the state chapter and Houston group of the Sierra Club.
The Katy Prairie includes agricultural wetlands, depressional wetlands, creek corridors, and coastal grasslands inhabited by hundreds of thousands of geese, ducks, herons, egrets, songbirds, and other wildlife.
The Sierra Club notes that the prairie is also a giant sponge that soaks up flood waters and keeps them from flooding down Buffalo Bayou, causing havoc downstream.
Nevertheless, last week the Texas Department of Transportation included the Grand Parkway Segment E in a list of projects to be funded in part with $181 million out of federal economic stimulus funds. That decision has generated controversy, in part because the project has not secured all the necessary permits to proceed, including a U.S. Army Corps of Engineers environmental permit.
Some groups question the use of federal stimulus money to construct a toll road, which is what the Grand Parkway is slated to be. The Sierra Club says there are proven transportation alternatives to the proposed Grand Parkway Segment E that will reduce traffic congestion where people live, work, and play.