One FoLAR's more prominent ongoing projects is the annual Great LA River Cleanup, which began in 1988 with a group of less than twenty people. In 2017, the Great LA Cleanup had up to 10,000 volunteers over three weekends covering the upper, middle, and lower sections of the River. On average, each volunteer at one of FoLAR's cleanups pulls 20l pounds of trash from the LA River. As of 2018, FoLAR has adopted a year-round cleanup model through partnerships with other environmental organizations like Heal the Bay, and through service opportunities for corporate groups and large organizations through River Makers program. In 2012, FoLAR raised a $1 million donation to support the completion of the ARBOR study by the United States Army Corps of Engineers (USACE). This study ultimately resulted in the adoption of Alternative 20, a restoration plan focused on 719 acres of habitat and pedestrian-friendly improvements, among other things. In 2016, an estimated 5,000 volunteers took place in the annual cleanup, including the mayor and several elected officials. In 2019, the FoLAR cleanup was the largest river cleanup in the United States. By that summer, kayaking in Los Angeles in the river had become common.