IntroductionIndonesia has designated 15 National Priority Lakes (Presidential Regulation No. 60/2021), yet quantitative baselines to assess sedimentation threats remain insufficient for most watersheds. This study evaluates Volume Development (VD) trajectories as early warning indicators of basin infilling in the Three Mahakam Lakes (Jempang, Melintang, Semayang)—a flood-pulsed tropical lake complex supporting the new capital city, Ibu Kota Nusantara (IKN).MethodsWe analyzed Landsat-derived shor