for the "Arroyo Seco Parkway" in 2004. The Plan was created through a partnership with the National Trust for Historic Preservation, the National Scenic Byways Center (Federal Highways), Caltrans (State Highways), the National Park Service, the Santa Monica Mountains Conservancy, and The Center for Preservation Education and Planning (CPEP Inc.). The Arroyo Seco Flood Control Channel, was built by the Works Progress Administration before and during construction of the parkway to avoid damages from future floods. Floods and controls The Arroyo Seco generally has a flow of several cubic feet per second, but periodically it is inundated by torrential floods from its steep, erosion-prone mountain watershed. The reputation of Arroyo Seco floods led the Spanish to site the original Pueblo de Los Ángeles away from the confluence of the Arroyo Seco and the Los Angeles River. Historically, these floods would race down the stream bed and overflow through Pasadena, South Pasadena, Alhambra and Los Angeles communities all the way to the Los Angeles River. As Los Angeles developed into a city and grew outwards, the damage from these floods was particularly severe in 1914 and 1916. Devil's Gate Dam In 1920, the Los Angeles County Flood Control District built the first flood control dam in Los Angeles County at Devil's Gate gorge. Named for a rock outcropping which resembles the face of a devil, this is the narrowest spot on the Arroyo Seco's course below Millard Canyon. The construction was by the Bent Brothers Company. Devil's Gate Dam in the Arroyo Seco in northern Pasadena between La Cañada Flintridge and Altadena is managed by the Los Angeles County Department of Public Works. The flood basin above the dam captures the flows of the mountain watershed of the Arroyo Seco. This area is now called "Hahamongna", a phrase meaning "Flowing Waters, Fruitful Valley". Hahamongna also refers to the original Native American tribe of the Tongva Indians who once inhabited the area. In 2011, the flood basin had filled with debris brought down after the 2009 Station Fire, reducing its effectiveness as a flood control measure. The County of Los Angeles conducted public hearings on the Environmental impact statement before selecting a method to remove debris from the Hahamongna area. In 2014, the Board of Supervisors approved a five-year project to remove 2.4 million cubic yards of sediment () from the basin despite strong opposition from neighbors and recreational enthusiasts. The opponents