Effect of Land Use Change on Groundwater Recharge Potential in the Water Catchment Areas of East Balikpapan

Abstract

Balikpapan City has experienced consistent population growth, with an increase of 19,000 residents in 2023 and an additional 4,600 people between January and March 2024. This population growth has significantly impacted land demand, particularly in East Balikpapan District, which covers an area of 137.16 km² with a population of 102,959 and a population density of 868.04 people/km². According to Balikpapan Mayor Regulation No. 22 of 2021 on the Detailed Spatial Plan (RDTR), and based on the Strategic Environmental Assessment (KLHS), a total of 630.34 hectares has been designated as water catchment zones across the sub-districts of Manggar, Manggar Baru, and Lamaru. However, the 2021–2026 Regional Medium-Term Development Plan (RPJMD) of Balikpapan indicates ongoing land use mismatches due to community practices that are inconsistent with spatial allocations. The 2023 Balikpapan Environmental Protection and Management Plan (RPPLH), through the DPSIR (Driving Force–Pressure–State–Impact–Response) analysis, indicates a decline in environmental carrying capacity caused by unplanned land clearing, reduced open spaces, and the shrinking of both water catchment areas and forest zones. An analysis of water catchment potential shows a notable shift: in 2014, 74% of the area was considered less suitable; in 2019, 58% was moderately suitable; and by 2024, 86% was moderately suitable. Land use conversion predominantly occurred between 2014–2019, with 136.99 hectares changing from fields/gardens to forest, and between 2019–2024, from forest to shrubs—both within high-potential zones.