Accurate and frequent monitoring of inland water body levels is essential for water sources and their ecological protection and management. Water bodies such as natural lakes and manmade dams provide an ecological environment for endangered animals and endemic plants and serve as irrigation and water source for human activities. However, in situ measurements or fixed observation stations are not always available for small to large water bodies. Here, we investigate water level changes at a regional level where endangered endemic species live in the Ramsar site, a nationally protected park, and inland waters using the National Aeronautics and Space Administration's Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) satellite launched in 2018. Most of the inland water bodies show high R-2 values ranging from 0.28 to 0.99 and the root mean square error values are widely distributed lower than 1 m. This study shows the potential and limitations of the new altimetry data source ICESat-2 ATL13 product for monitoring the long-term behavior of inland water reservoirs for sustainable monitoring.