Tank renovation near Dhamlewada
tank-5 · 21.5204, 79.8014 · Tumsar taluka · PIN 441915
Contributing catchment 1.31 km² · at a 3 m bund it impounds 1,876 thousand m³ over 69 ha · design monsoon yield 1,175 thousand m³ · soil HSG-D (clay 40%).
In plain words
The most certain site in the shortlist — a large reservoir near Dhamlewada (Tumsar) that both satellites watch filling and emptying in near-perfect step, and that the global lake inventory independently confirms. Every monsoon it brims to reservoir scale, then draws down to almost bare ground by summer.
What to build
Renovate — desilt and strengthen the existing malguzari tank. No new dam, and no land to acquire (the nearest house is over a kilometre away).
Why here
The steep fall from full to empty is the signature of a silted, shallow bed that can no longer carry water into the dry months. The asset already exists and is trusted by three independent sources; the problem is lost depth, not a lack of water.
How
Remove the accumulated silt to restore depth, strengthen the bund and waste weir, and clear the feeder channels so the catchment keeps filling it.
The delta — now vs after
Today it is brim-full in August and bare by April. Restored, it would hold water months longer — turning a monsoon-only pond into a dry-season lifeline for irrigation, drinking supply and recharge across the surrounding clay lowland.
What it delivers · indicative
Live capacity from the observed satellite extent (607 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
≈ 8,645 thousand m³ of net-new water · 1,729 ha irrigable · 157,182 drinking person-years.
recovered draw-down (576 ha of 607 ha peak) x 1.5 m — the water it loses to summer today. The site already carries ≈454 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, 37 scenes). Radar peak vs summer low: 606.6 → 30.3 ha, a 576.3 ha annual draw-down — the storage renovation recovers.
Area-capacity (DEM, 30 m) · gross storage by bund height
Cross-witness & confidence — independent corroboration
Two sensors track together
Optical (S2) and radar (S1) rise and fall together with correlation r = 0.9 across 37 paired months. Absolute extents match 87% — a close magnitude match strengthens the read on an open water body.
Independent inventory (HydroLAKES)
Confirmed: a mapped lake 0 m away, 163 ha, watershed 64.7 km², volume 29 MCM.
Land acquisition (submergence)
A 3 m bund would submerge 69 ha — the land to be acquired. Cost & consent scale with this.
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
1,068 m
to the closest mapped building.
Within 500 m
0
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
Dhamlewada
988 m away · Tumsar taluka · PIN 441915
Nearest landmark
Chandpur Fort
Schools within 2 km
0
Health within 2 km
0
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)
Greening (more vegetation)Vegetation (NDVI) change
+0.071
7 ha lost · 128 ha gained over 1,285 ha land
Built-up (NDBI) change
5.3 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.