onto the beach—is at times alarmingly high, often surpassing the legal limit for California. As a result, the area where the creek meets the sea, and the creek itself, are considered permanently off limits to swimmers and bear prominent signs that warn of the dangers of trespassing into such toxic waters. Nevertheless, people do, almost daily. Officials from the Orange County Environmental Health Department say that skin rashes, infections, "pink eye" and other assorted ailments are not uncommon to those who use Aliso Beach and, unwittingly, come in contact with the creek and its invisible bacteria...". Urbanization has also changed sediment transport in the creek. The obstruction of natural sediment sources and increased water flow due to urban runoff has caused significant downcutting in the river bed. The creek has eroded to depths exceeding below its original bed in some areas, disconnecting the creek from its natural floodplain and riparian zones. In 2017 the U.S. Army Corps of Engineers reported that $5 million of damage had been caused by erosion along lower Aliso Creek. This includes physical damage to creek banks, bridges, roads and water pipelines. Landslides have occurred along the creek and its tributaries, including at English Canyon in the 1990s. The creek is estimated to deliver 20,000–60,000 tons of sediment to the sea in an average year, and as much as 200,000 tons in wet years. The South Orange County Wastewater Authority (SOCWA) Coastal Treatment Plant is located next to Aliso Creek in Laguna Beach, and treats about 2.9 million gallons (11 million litres) of sewage each day. Treated wastewater is discharged into the Pacific Ocean about offshore from Aliso Beach via the Aliso Creek Ocean Outfall. A pipeline carrying raw sewage downstream to the treatment plant and two pipelines carrying treated sludge back upstream to SOCWA's Regional Treatment Plant in Laguna Niguel for recycling are buried roughly parallel to the creek within Aliso Canyon, and have been frequently threatened by flooding and erosion. Sewage spills have occasionally entered the creek, forcing the closure of Aliso Beach. In 2016, the California Coastal Commission approved a project to replace the two treated sludge lines, which had deteriorated extensively over the last 30 years. Restoration projects There have been several attempts to clean up the creek, stabilize its banks and restore native habitat. One of the earlier projects was Aliso Creek Wildlife Habitat Enhancement Project (ACWHEP), conceived and jointly funded