NATURAL SPRINGS AND LATERITIC AQUIFERS IN WESTERN MAHARASHTRA, INDIA: ECO-HYDROGEOLOGICAL SIGNIFICANCE AND CONSERVATION IMPERATIVES

Natural springs in the Western Ghats and Konkan plains of India are crucial for sustaining freshwater ecosystems by providing baseflows to streams. They serve as vital drinking water sources for millions in rural communities while supporting riparian vegetation and biodiversity. Fed predominantly by lateritic aquifers, spanning 4,910.87 sq. km in western Maharashtra with thicknesses of 5–45 m, these springs exhibit diverse typologies influenced by geomorphology, aquifer characteristics, and discharge rates. The aquifers occur in two geomorphological units: low-level laterites (0–284 m amsl) along the Konkan coastal plain and high-level laterites (970–1,439 m amsl) in the Western Ghats. Together, they sustain over 2,200 natural springs, providing refugia for spring dependent organisms.

Spring typologies include contact, depression, gravity, fracture, and thermal springs, classified into Fourth to Eighth magnitude based on Meinzer’s system. Low-level lateritic springs are typically rheocrene or limnocrene types with discharge ranging from 10–100 GPM, while high-level springs include contact and gravity springs with lower discharge (1–10 GPM). Thermal springs along lineaments exhibit higher discharge, mineral content, and fall into the Fourth magnitude.

Water quality data from 47 locations reveal significant variability. Low-level laterite springs show pH 6.8–8.5, TDS 52–488 mg/L, and hardness 52–276 mg/L, while high-level springs exhibit pH 7.1–8.3, lower TDS (38–175 mg/L), and hardness (35–180 mg/L). Thermal springs show elevated TDS (230–1,280 mg/L), hardness (120–580 mg/L), and minerals such as Na (15–175 mg/L) and HCO₃ (124–490 mg/L). Bacteriological contamination is rare in protected springs but occurs near settlements.

This study highlights the eco-hydrogeological significance of lateritic aquifers in sustaining springs, streams, rivers, and wetlands, especially during peak summer months. It also underscores their role in supporting biocultural hotspots like sacred groves (Devrai) and petroglyphs. However, these ecosystems face threats from land-use changes, aquifer degradation, and pollution. The study advocates for eco-hydrogeological research and conservation to ensure the sustainability of these fragile groundwater-dependent ecosystems in Western Maharashtra.