Thread by @IndHydrogeology

Thread: Delhi has a lot of GW, as its on a thick alluvial aquifer formed by Yamuna. But the GW situation is grave because most of the GW is salty (Orange in map) & unusable!

Snippets from the recent National Project for Aquifer Management (NAQUIM) report by @CGWB_CHQ

This map shows thickness of fresh-water left. If you have lived in areas of west Delhi like Dwarka you would know how salty the groundwater is.

This map shows how over a decade the water levels (top/freshwater) have decreased. Decrease of ~ 2 meters on an average.

Unsustainable considering that the remaining freshwater thickness is less than 10 meters in many areas.

This water table contour map is useful to see the areas where most of the extraction and recharge is happening. For instance, much recharge in JNU-Sanjay Van (~220m) & extraction in nearby HauzKhas-GK (~165 m).

Depth to water should not be used as ground topography varies.

NAQUIM recommends:
- Regulation in most areas (Green Dots)
- Extraction in some areas (green shaded, incl Yamuna Plains)
- Refraining in some areas (pink dots, mostly along Najafgarh drain)

@DelhiJalBoard Communicating the amount of freshwater left in their area can be a powerful way to motivate citizens for water conservation. @ankit_delhii

Delhites know the importance of freshwater, considering in some areas DJB supplies freshwater for 2 hours & salt water much longer on the same tap!

Its time they are transparently educated about how much fresh-water they have.

It is well established how freshwater extraction causes up-coning of saltwater. Thus extraction must be regulated based on areas.