Tank renovation near Mahalgaon
tank-11 · 21.0351, 80.0374 · Sakoli taluka · PIN 441802
Contributing catchment 438.5 km² · soil HSG-C (clay 38%).
In plain words
An existing tank near Mahalgaon (Sakoli) — close to the mapped Lawari Lake — that both sensors see swing seasonally (optical 82 → 0, radar 55 → 0). It displaces no one. It sits at low confidence because the two sensors track only weakly (correlation 0.48) and disagree on extent, and no inventory lake falls within the confirmation range (nearest ~1.9 km).
What to build
Ground-truth the water body and its relationship to Lawari Lake; if it is a distinct, renovable tank, desilt and strengthen.
Why here
The seasonal signal is clear and there is no displacement, but the weak sensor agreement and the absence of an inventory confirmation mean a ground check must establish what is actually here before funds are committed.
How
A field visit to confirm the tank is distinct from the adjacent lake and check the developing land nearby; then renovate if confirmed.
The delta — now vs after
If it is a real tank distinct from Lawari Lake, a clean no-displacement renovation; if it is backwater of the lake, drop it.
What it delivers · indicative
Live capacity from the observed satellite extent (82 ha) x 1.5 m mean depth. Desilting restores the depth lost to siltation — the tank empties to near-nothing by summer today, so recovered depth means water held later and more recharge. Irrigation ~5 TCM/ha; drinking 150 lpcd. Actual yield varies with monsoon reliability, seepage and siltation.
Incremental over today · the net-new gain, from the 4-year record
≈ 715 thousand m³ of net-new water · 143 ha irrigable · 13,000 drinking person-years.
recovered draw-down (48 ha of 48 ha peak) x 1.5 m — the water it loses to summer today. The site already carries ≈3 thousand m³ into summer today — that is not counted; only the recovered draw-down is new.
Why this site
An existing water body — desilting and strengthening recovers lost storage at a fraction of new-build cost.
Seasonal water extent · dual-sensor
Radar (S1, 48 passes) fills the monsoon gap that cloud hides from optical (S2, 38 scenes). Radar peak vs summer low: 47.8 → 0.2 ha, a 47.6 ha annual draw-down — the storage renovation recovers.
Cross-witness & confidence — independent corroboration
Two sensors track together
Optical (S2) and radar (S1) rise and fall together with correlation r = 0.48 across 38 paired months. Absolute extents match 29% — a close magnitude match strengthens the read on an open water body.
Independent inventory (HydroLAKES)
No HydroLAKES polygon within 800 m (nearest 1,907 m) — likely seasonal water not in the global inventory; treat as unconfirmed.
Land acquisition (submergence)
Submergence not computed for this structure type.
Low confidence — sensors disagree and no independent lake confirms this site. It must be ground-truthed before any commitment of funds.
Displacement witness — real building footprints
No structures in footprintIn the submergence footprint
0
a renovation floods no new land — desilting restores depth within the existing waterspread, so nothing is displaced.
Nearest structure
194 m
to the closest mapped building.
Within 500 m
41
buildings in the influence ring.
Restoring lost depth within the existing waterspread raises no new water level and acquires no new land, so no one is displaced. Verify bed encroachment on the historical spread on the ground before restoring the full level.
Overture Maps buildings 2026-05-20.0 (union of OSM / Google Open Buildings / Microsoft / Esri), Bhandara admin_code=506. A desktop displacement screen — precedes, not replaces, cadastral (7/12) verification.
Reconnaissance context & access — Ola + Google Places
Nearest habitation
Mahalgaon
1,873 m away · Sakoli taluka · PIN 441802
Nearest landmark
Lawari Lake
Schools within 2 km
1
nearest 1,887 m
Health within 2 km
1
nearest 1,801 m
Google Places (New) searchNearby + Ola Maps Places nearbysearch · reconnaissance-grade. Independent witness to the buildings displacement layer — dense amenities near a site corroborate high displacement. Does not replace cadastral 7/12 records, geotechnical bores or a level survey.
Human pressure — land-cover change (2022 → 2026)
Stable land coverVegetation (NDVI) change
-0.016
218 ha lost · 85 ha gained over 1,753 ha land
Built-up (NDBI) change
208.4 ha
new built-up / bare (construction proxy)
Window
2022-11..2023-02 (8 scenes)
→ 2025-11..2026-02 (8 scenes)
Sentinel-2 L2A dry-season MEDIAN composites (2022-23 vs 2025-26), water-masked; NDVI+NDBI change screen — not cadastral or DEM cut/fill
DPR-grade desktop hydrology from Copernicus GLO-30 (30 m) + ISRIC SoilGrids + ESA WorldCover; water extent from Sentinel-2 L2A MNDWI (optical) and Sentinel-1 GRD VV radiometrically calibrated to σ⁰ (DN²/sigmaNought² from the product calibration LUT, GCP thin-plate-spline geocoded, open water at σ⁰ < −17 dB; thermal-noise floor not subtracted). A desktop assessment that precedes — not replaces — the statutory ground & geotechnical survey.