Borewell Recharge Design: Sizing, Filter Media, and CGWB Compliance
Borewell recharge is the most cost-effective artificial recharge method for hard-rock aquifers of peninsular India, where over 60% of urban and rural water supply depends on borewells. This guide covers the full design chain: inlet chamber, silt trap, filter media, casing depth, and connection to the borewell annulus.
Design a borewell recharge system →
When to choose borewell recharge over recharge pits
Borewell recharge is preferred when the top 3–10 m is clayey or low-permeability, when large volumes must be recharged rapidly (>10,000 L/hr), or when an existing dry or low-yield borewell is available for reuse.
Recharge pits and trenches work in sandy or gravelly soils with high infiltration capacity. Rain GEO SAT auto-selects the structure using soil texture from SoilGrids and Bhuvan.
Design components and typical dimensions
A standard borewell recharge system has four components: inlet chamber (1 m × 1 m × 1.5 m), silt trap (0.6 m × 0.6 m × 0.6 m), filter chamber (1.2 m diameter × 2 m deep), and PVC connection to the borewell annulus (100–150 mm).
- Inlet chamber — receives rooftop or catchment runoff via first-flush diverter
- Silt trap — coarse sand + gravel to remove suspended solids
- Filter media — bottom 0.5 m boulders (40–65 mm), middle 0.5 m gravel (20–40 mm), top 0.5 m coarse sand
- Recharge pipe — perforated PVC into the borewell annulus below casing
- Overflow — safety pipe at inlet chamber to prevent flooding
Indicative cost and payback
Typical cost for a residential borewell recharge structure in India is ₹18,000–₹45,000 depending on soil excavation difficulty and filter material availability. For a 200 m² rooftop in a 900 mm rainfall zone, harvested volume offsets tanker cost within 2–4 years and typically raises the water table around the borewell by 1–3 m within two monsoons.
Frequently asked questions
- Can I recharge a functional (yielding) borewell?
- Yes, provided filtration is adequate. Rain GEO SAT recommends triple-media filtration (boulders + gravel + coarse sand) and periodic maintenance every 6 months to prevent clogging.
- What is the maximum recharge rate?
- For hard-rock aquifers, 10,000–20,000 L/hr per borewell is typical. Alluvial aquifers can accept 50,000+ L/hr. The Expert engine estimates this from aquifer transmissivity.
- Do I need CGWB permission?
- For artificial recharge into a private borewell for own use, no permission is typically required. Commercial or industrial deep recharge may require SEIAA or CGWA clearance depending on the state.
Ready to apply this on your site?
Rain GEO SAT calculators use IMD, NASA POWER, Open-Meteo, and CGWB data to deliver engineer-grade rainwater harvesting and groundwater recharge designs.
Related guides
- Rainwater Harvesting Calculator: Rooftop Yield, Tank Volume & Recharge Sizing
- Groundwater Recharge Design: Pits, Trenches, Shafts, and Percolation Tanks
- Stormwater Drain Design: Rational Method, IDF Curves, and Peak Discharge
- Watershed Analysis Guide: Delineation, Flow Direction (D8), and Recharge Prioritisation
- ESG Water Reporting: GRI 303, CDP Water Security, and BRSR Compliance
- Water Positive Certification: CII-GBC, AWS Standard, and Verification Pathway