The Mahakam Delta in East Kalimantan is the largest in Indonesia and is located in the Makassar Strait. Based on Landsat images in 1995, the delta was overgrown with mangroves and had only a few ponds. In the following years, 2000, 2010, and 2022, these ponds grew and replaced the mangroves. The current rate of mangrove degradation is faster than the rate of data collection and mangrove mapping. Rapid and accurate mapping of mangroves is urgently needed to provide information on the current status to monitor mangroves’ changes and better manage them in the future. The automatic mangrove map and index (AMMI index) generates mangrove maps automatically, and the automatic shoreline map (ASM) index maps water bodies, especially ponds, rivers, and shorelines. Using these indexes, the mangrove area in 1995–1996 was 82,203.9 ha, while the pond area was only 3575.7 ha. The rapid increase in ponds is shown in Landsat 2000 imagery, which shows 43,935 ha of mangroves and 14,145 ha of ponds area. This significant increase in the pond area is due to the depreciation of the rupiah against the US dollar, which led to an increase in the export of pond resources as they became more profitable. By 2021–2022, the remaining mangrove area was 24,732.36 ha, while the pond area increased to 29,975.9 ha. This chapter applies a model using the two indices that automatically, quickly, and accurately inform about changes in mangroves, ponds, and shorelines multi-temporally using the Google Earth Engine (GEE) platform.