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State Profile
Ground Water Scenario
Assam
Area (Sq.km) |
78,438 |
Physiography |
- Brahmaputra Valley.
- The Central Assam Ranges.
- Barak Valley.
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Drainage |
Brahmaputra Basin with sub basin of
Subansiri, Jia Bharali, Badeng-Pubnoi.
Dhansiri, Manas, Champamati Kalang.
Meghna Basin with sub basin of Barak river |
Rainfall |
2262.95 mm with 144 rainy days |
Total Districts / Blocks |
23 districts / 219 Blocks |
GROUND WATER MEDIUM (Hydrogeological Conditions)
Hydrogeologically the state can be divided into three units namely consolidated formation; semi consolidated formation and unconsolidated formations. More than 75% of the state is underlain by unconsolidated formations comprising of clay, silt, sand, gravel, pebble and boulders. The Bhabar belt is about 11 to 15 km wide; the tubewells yield 27 to 59 m3/hr in this zone. The Tarai zone follows immediately down slope of the Bhabar zone where the yield of the wells ranges between 80-240 m3/hr. The flood plains follow the Tarai in Brahmaputra valley where the shallow tubewells yield between 20-50 m3/hr and deep tubewells between 150-240 m3/hr. In the semi consolidated formations of Cachar district, the yield of the tubewell ranges between 50 to 100 m3/hr.
GROUND WATER EXPLORATION/SOURCES FINDINGS
Dynamic Resources |
Annual Replenishable Ground water Resource |
27.23 BCM |
Net Annual Ground Water Availability |
24.89 BCM |
Annual Ground Water Draft |
5.44 BCM |
Stage of Ground Water Development |
22 % |
Developmental Monitoring |
Over Exploited |
NIL |
Critical |
NIL |
Semi- critical |
NIL |
Exploratory Tube wells Constructed (as on 31.03.2007) |
304 |
No. of ground water observation wells
|
381 |
Artificial Recharge to Ground Water (AR) |
250 Check Dams, 500 weirs, 1000 Gabion structures, 250 development of springs 600 RWH in Urban Areas |
AR schemes completed during IX Plan:
1 |
Ground Water Quality Problems |
Contaminants |
Districts (in parts) affected |
Iron |
Northern Bank of Brahmaputra |
Fluoride |
Kamrup, Nagaon, Karbi Anglong |
Enactment of Ground Water Bill to regulate and control the development of ground water:
“The Assam Ground Water Bill” has been prepared by the Government of Assam to regulate and control the development of ground water, which has been referred to Law Department for vetting. Necessary action is being taken for finalization.
Inclusion of Roof Top Rain Water Harvesting (RTRWH) in building by laws:
To be included.
Central Ground Water Authority
Areas Notified |
For Regulation of ground water development |
NIL |
For Registration of GW abstraction Structures |
NIL |
Mass Awareness Programmes (as on 31.03.2007) |
12 |
Water Management Training Programme (as on 31.03.2007) |
8 |
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Ministry
of Water Resources