The San Antonio River Authority will thin out the trees in the Mission Reach area of the San Antonio River over the next four months. SARA's annual Stem Density Removal program aims to keep overgrowth from expanding the floodplain. The work will be concentrated along a stretch of a bit more than two miles between South Alamo Street and Confluence Park. SARA says the project may last through February. The annual project is carried out in the fall and winter so as not to disturb birds during the nesting season.