tanggul

Tanggul is an embankment or levee constructed along rivers, coasts, or reservoirs to prevent flooding and control water flow. It is typically built from compacted earth, clay, and sand, and may be reinforced with rock, concrete, or gabions. The primary purpose is to keep land dry during high water levels and to guide water along safe channels. In practice, tanggul protects farmland, settlements, and infrastructure in flood-prone areas.

Types include river embankments (tanggul sungai) and coastal dikes (tanggul pesisir), designed to withstand river floods and tidal surges, respectively. Some structures combine both functions in delta regions.

Design and construction involve calculating the crest height and width based on extreme water levels and land use. A stable slope on both sides, an impermeable core or seepage cutoff, and proper drainage are essential. Erosion protection on the outer slope, through grass cover, concrete panels, or riprap, extends the structure’s life.

Maintenance and safety require regular inspections for seepage, cracking, piping, and slope movement. Repairs may involve soil stabilization, piping prevention measures, or reinforcement. Overtopping risk is mitigated by raising crest elevations or linking with flood-storage and pumping schemes.

Context: Tanggul are common in Indonesia, Southeast Asia, and other flood-prone coastlines. They are a key component of flood risk management and coastal defense, and are distinct from dams that store water.