HIFLD OPEN Lock Traffic Signal Stations (USACE IENC)

The USACE IENCs coverage area consists of 7,260 miles across 21 rivers primarily located in the Central United States. IENCs apply to inland waterways that are maintained for navigation by USACE for shallow-draft vessels (e.g., maintained at a depth of 9-14 feet, dependent upon the waterway project authorization). Generally, IENCs are produced for those commercially navigable waterways which the National Oceanic and Atmospheric Administration (NOAA) does not produce Electronic Navigational Charts (ENCs). However, Special Purpose IENCs may be produced in agreement with NOAA.

美国陆军工程兵团（United States Army Corps of Engineers, USACE）所辖内河电子航海图（Inland Electronic Navigational Charts, IENCs）的覆盖范围涵盖美国中部地区21条河流，总里程达7260英里。IENCs适用于由美国陆军工程兵团维护、供浅吃水船舶航行的内陆航道（例如，航道维护水深为9至14英尺，具体标准根据航道工程授权要求确定）。通常而言，IENCs专为美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）未制作电子海图（Electronic Navigational Charts, ENCs）的商业通航航道编制。不过，经与美国国家海洋和大气管理局协商后，可编制专用内河电子航海图（Special Purpose IENCs）。