In Arvada Urban Renewal Authority v. Columbine Professional Plaza Association, Inc., 85 P.3d 1066 (Colo. 2004), the City of Arvada had designated a 500-acre tract for redevelopment. After a portion of that tract had been redeveloped pursuant to the redevelopment plan, the city "formally released" it. But, when one of the buildings on that portion became vacant, the city initiated a condemnation action. Holding that the city could not condemn that land under the existing redevelopment plan, the Supreme Court of Colorado stated that once the purpose of the renewal plan had been achieved -- the elimination or prevention of the spread of slum or blight -- "an authority may no longer rely on a municipality's initial blight determination to condemn property because it can no longer exercise its condemnation powers in furtherance of a valid public purpose." Id. at 1073.