SIOUX FALLS — One of several proposed pipeline systems to deliver Missouri River water in South Dakota could cost $8.4 billion to $10 billion, according to estimates shared Monday. Dakota Mainstem Regional Water System Executive Director Kurt Pfeifle was on a panel speaking to the Rotary Club of Downtown Sioux Falls. Pending federal legislation sponsored by South Dakota’s congressional delegation would provide funding to help with that study and two other studies for the proposed Western Dakota Regional Water System pipeline, which has an estimated projected cost of $4 billion, and a planned expansion of the Lewis and Clark Regional Water System in southeast South Dakota, which has an estimated project cost of $2.5 billion. Lewis and Clark Regional Water System Executive Director Troy Larson and Minnehaha Community Water Corporation Executive Director Scott Buss were also on the panel. Construction began on the Lewis and Clark system in 2003 and is ongoing, although the constructed portion already serves 20 member cities and rural water systems.