A Streamflow Forecasting System for the Operation of the Panama Canal

A state of the art rainfall and river forecasting system has been implemented by the ACP (Panama Canal Authority) to assist in daily operations of the Panama Canal. More accurate forecasts of precipitation, and inflows and elevations for the reservoirs that provide water for canal operations will help ensure an adequate water depth for the more than 13,000 ships that transit the canal each year. The project to design and install the system is the result of an agreement between the Panama Canal Commission and the U.S. National Oceanic and Atmospheric Administration's National Weather Service Office of Hydrology [NOAA NWS/OH] signed in August 1996. The National Weather Service and its contractors developed, implemented, and integrated the forecasting system for the Meteorological and Hydrographic Branch of the canal’s Engineering Division. The work involved the integration of two distinct projects – the development of a mean areal precipitation reporting and forecasting system (PANMAP) linked with a streamflow and reservoir operation simulation and forecasting system (PANFCST). The Hydrologic Research Center, San Diego, California, developed the PANMAP system which uses radar, climate station measurements, and model forecasts to produce estimates of MAP (mean areal precipitation) over each of the nine sub-basins in the 1,289 square miles (333,851 ha) canal watershed. These precipitation values are then provided to the PANFCST system, implemented by RTi (Riverside Technology, inc.), Ft. Collins, Colorado. PANFCST computes simulations and forecasts of inflows to and pool elevations in the reservoirs that provide the water for canal operations. The NWS International Hydrologic Technology Transfer Center provided project management and coordinated integration activities. When the canal was opened in 1914, Gatun Dam, built across the Chagres River as it entered the Atlantic Ocean, was one of the largest earthen dams in the world. The lake behind the dam covers an area 164.1 square miles (42,500 ha) and forms most of the navigable portion of the canal (Figure 1). Madden Dam, completed in 1936, is also located on the Chagres River, approximately ten miles (16.1 km) upstream from the central portion of the canal near the continental divide. Gatun Lake provides most of the water essential for ship transits through the waterway, while Madden Lake collects water from the upper reaches of the watershed, providing an additional supply of water for ship transits and flood protection. Both Gatun and Madden Dams provide hydroelectric power and drinking water for the residents of Panama.