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Bhandara Water Watch
Percolation tank · pt-3 Sensor-witnessed nala flow medium confidence · medium

Percolation near Hingana

pt-3 · 21.4065, 79.7094 · Tumsar taluka · PIN 441912

Contributing catchment 8.07 km² · at a 3 m bund it impounds 158 thousand m³ over 17 ha · design monsoon yield 2,996 thousand m³ · soil HSG-C (clay 40%).

In plain words

A percolation-tank site near Hingana (Tumsar) on lighter HSG-C soil, where the sensors track the seasonal fill well (correlation 0.74). The blocker is land: six buildings fall inside the 3 m footprint, the nearest only about 59 m away.

What to build

Survey the six structures — and test whether a lower bund clears them — before committing; the recharge case is otherwise sound.

Why here

HSG-C soil makes this a genuine recharge site (around a third of storage percolates) and the flow is well witnessed; the only real question is whether the six nearby structures can be avoided or the bund lowered.

How

Cadastral + ground check of the six structures; an area-capacity trade-off for a lower bund that keeps useful storage while clearing the buildings.

The delta — now vs after

Clear the land and Hingana gains a recharge tank; if the structures cannot be avoided, a lower design or a drop.

What it delivers · indicative

Impoundment
158 TCM
Irrigation
32 ha
Drinking (person-yrs)
2,876
Recharge
55 TCM

Indicative benefit at a 3 m bund (DEM area-capacity at 3 m bund) under standard norms (irrigation ~5 TCM/ha; drinking 150 lpcd). Recharge is limited on HSG-D clay (35% of storage). Actual yield varies with monsoon reliability, seepage and siltation.

Incremental over today · the net-new gain, from the 4-year record

158 thousand m³ of net-new water · 32 ha irrigable · 2,873 drinking person-years.

full design storage — no structure holds water here today.

Why this site

Priority
64
Strahler
2
Slope
1.5%
Catchment
8.07 km²
Runoff CN
79
Lineament
0 km/km²

Sited where soil is lighter (HSG-C) or fractures raise infiltration — a percolation tank turns runoff into recharge rather than surface storage.

Seasonal water extent · dual-sensor

2022-06
2022-06-070 ha · MNDWI
90 ha— S2 optical — S1 radar2022-062026-05

Radar (S1, 48 passes) fills the monsoon gap that cloud hides from optical (S2, 38 scenes). Radar peak vs summer low: 1.70 ha, a 1.6 ha annual draw-down — the storage renovation recovers.

Area-capacity (DEM, 30 m) · gross storage by bund height

2 m413 m1584 m3715 m686storage · thousand m³ (bars)submergence · ha (line)
Catchment
8.07 km²
Bed elevation
270 m
Design yield
2,996 TCM
Fill ratio @3 m
18.9×

Cross-witness & confidence — independent corroboration

Two sensors track together

Optical (S2) and radar (S1) rise and fall together with correlation r = 0.74 across 38 paired months. Absolute extents match 0% — they differ by sensor physics on a flowing nala, so the shared rhythm is the witness, not the magnitude.

Nala flow (new-build site)

No existing lake here — expected for a new structure. Sensors confirm a monsoon flow pulse in the nala; nearest mapped lake is 4,784 m away.

Land acquisition (submergence)

A 3 m bund would submerge 17 ha — the land to be acquired. Cost & consent scale with this.

Displacement witness — real building footprints

Several structures — survey needed

In the submergence footprint

6

buildings within the 231 m design-submergence radius (17 ha pond at 3 m).

Nearest structure

59 m

to the closest mapped building.

Within 500 m

33

buildings in the influence ring.

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

Hingana

153 m away · Tumsar taluka · PIN 441912

Nearest landmark

Mitewani.P.H Railway Station

Schools within 2 km

3

nearest 696 m

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)

Stable land cover

Vegetation (NDVI) change

+0.032

34 ha lost · 116 ha gained over 1,856 ha land

Built-up (NDBI) change

15.9 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.