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Bhandara Water Watch
Percolation tank · pt-6 Sensor-witnessed nala flow low confidence · reservoir-scale

Percolation near Kudegaon

pt-6 · 20.7346, 79.8278 · Lakhandur taluka · PIN 441803

Contributing catchment 3.42 km² · at a 3 m bund it impounds 5,712 thousand m³ over 338 ha · design monsoon yield 1,674 thousand m³ · soil HSG-C (clay 39%).

What it delivers · indicative

Impoundment
5,712 TCM
Irrigation
1,142 ha
Drinking (person-yrs)
103,849
Recharge
1,999 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

5,712 thousand m³ of net-new water · 1,142 ha irrigable · 103,855 drinking person-years.

full design storage — no structure holds water here today.

Why this site

Priority
66
Strahler
2
Slope
0.2%
Catchment
3.42 km²
Runoff CN
85
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
236 ha— S2 optical — S1 radar2022-062026-05

Radar (S1, 48 passes) fills the monsoon gap that cloud hides from optical (S2, 40 scenes). Radar peak vs summer low: 202.90 ha, a 202.9 ha annual draw-down — the storage renovation recovers.

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

2 m24383 m57124 m91055 m12509storage · thousand m³ (bars)submergence · ha (line)
Catchment
3.42 km²
Bed elevation
227 m
Design yield
1,674 TCM
Fill ratio @3 m
0.3×

Cross-witness & confidence — independent corroboration

Two sensors track together

Optical (S2) and radar (S1) rise and fall together with correlation r = 0.33 across 40 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 show only a weak flow signal in the nala; nearest mapped lake is 12,300 m away.

Land acquisition (submergence)

A 3 m bund would submerge 338 ha — the land to be acquired. Cost & consent scale with this.

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

Settlement in footprint — major acquisition

In the submergence footprint

426

buildings within the 1,038 m design-submergence radius (338 ha pond at 3 m).

Nearest structure

106 m

to the closest mapped building.

Within 500 m

60

buildings in the influence ring.

The design submergence overlaps a settlement — this site would require major land acquisition and resettlement, or a lower bund. Not viable at this height without displacement.

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

Kudegaon

864 m away · Lakhandur taluka · PIN 441803

Nearest landmark

Manoj Pan Shop

Schools within 2 km

1

nearest 864 m

Health within 2 km

5

nearest 284 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 cover

Vegetation (NDVI) change

+0.053

104 ha lost · 381 ha gained over 1,864 ha land

Built-up (NDBI) change

72.4 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.