Overview

The Gayatri Reservoir is constructed across Suvarnamukhi river near Kariyalla village in Hiriyur Taluk of Chitradurga district in the year 1963. The total length of the reservoir is 1021.53 m with gross storage capacity of 27.63 mcum (0.97 TMC), dead storage capacity of 9.55 mcum (0.34 TMC) & live storage capacity of 18.08 mcum (0.63 TMC). The total water spread area of the reservoir is 1831.00 Sq Km.

Salient Features of the Project

Name of the project Gayathri Reservoir Project
Name of the river Suvarnamukhi
Location of dam Near Kariyala village of Hiriyur taluk in Chitradurga District
Longitude 760 44′ 00″ E”
Latitude 140 47’ 0” N
Status Completed

Geophysical features

Total Catchment area 1831.00 sq km ( 707.00sq mile)
Independent catchment area 365.00 sq km ( 141.00sq miles)
Intercepted catchment area 1466.00 sq km ( 566.00sq miles)
Nature of catchment Plain and hilly region with a mean annual rainfall of 584 mm
Mean annual rainfall 584 mm (23 inches)
Climate Moderate with annual mean temperature of 310 C
General Characteristics of Soil in the Command area Red & B C Soil
Average yield at dam site At 75% dependability:-19.58 mcum (691.65 mcft)
  At 50% dependability :– 32.90 mcum (1161.71 mcft)
   
  Yield available from Boranakanive reservoir (which is intercepted catchment) is 12.52 mcum and the yield available from the independent catchment area is 2.82 mcum i.e., totally 15.34 mcum of yield is available at site.
   
Geological features 1.Regional geology :- Granites and granitic gneissis of peninsular gneissic comlex exist.
  2. Geology at dam site :- Highly foliated and weakened chlorite schists and quartzites of dharwar super groups exists at the site.

Index Map of Gayathri Reservoir

Technical Details

Gross storage capacity 27.63 mcum (0.97 tmc)
Dead storage capacity 9.55 mcum (0.33 tmc)
Live storage capacity 18.08 mcum (0.64 tmc)
Capacity at FRL 27.63 mcum (0.97 tmc)
Capacity at MDDL 9.55 mcum (0.33 tmc)
Reservoir Evaporation Losses 5.67 mcum (0.20 tmc)
Reservoir filling & depletion details  
a. Filling period 627.45m (1997)
b. Depletion period 623.80m (2004)
Levels in Mts\Ft  
Average river bed level RL 612.52 m (RL 2009.60 ft)
Lowest foundation level RL 610.08 m (RL 2001.60 ft)
Dead storage level RL 622.27m (RL 2041.60 ft)
Full reservoir level RL 626.85m (RL 2056.60 ft)
Maximum reservoir level RL 628.98m (RL 2063.60 ft)
Minimum Draw down level RL 622.27m (RL 2041.60 ft)
Crest level RL 626.85m (RL 2056.60 ft)
Top of dam level RL 629.18m (RL 2064.30 ft)
Masonary dam —-
Earthen Dam RL 629.18m (RL 2064.30 ft)
Top of Parapet Level —-
Maximum Water spread area 566.96 ha ( 1400.39 acres)

Type of dam Composite type
Length of the dam (kms) 1.021 Kms
Max height of dam above deepest foundation level (Mts/Fts) Earthen dam=13.55m (44.45 ft)
Max height of dam above lowest river bed level (Mts/Fts) 16.66 m
  (RL 629.18 m – RL 612.52m)
Top width of dam(Mts/Fts) 3.65 m (12 ft)
Slopes in Dam section
a. Earthen Dam (upstream) U/S: 1.50:1
b. Earthen Dam (downstream) D/S: 2:1
c overflow section (upstream) Central Ogee way
d overflow section (downstream) Central Ogee way
Drainage Gallery NA
a.Length Left side(Mts/Fts) NA
Right side(Mts/Fts) NA
b.Size(Mts/Fts) NA
c.Floor Level(Mts/Fts) NA
Spillway  
Type Central Ogee way
Total Length 65.53 m (215 ft)
Discharging Length 65.53 m (215 ft)
Crest width Ogee way type
Crest Level RL 626.85m (RL 2056.60 ft)
No of crest gates No
Maximum Flood intensity 441.75 cumecs (15600 cusecs)
Maximum Flood lift RL 628.98m (RL 2063.60 ft) 2.13 m above crest level
Maximum Discharging capacity over spillway 441.75 cumecs (15600 cusecs)
Energy dissipating arrangements Stilling basin of 18.29 m length with 0.90m high RCC end wall to provide water cushion.
River sluice No

Irrigation Sluice Two ,Left bank sluice/Right bank sluice
Numbers 01 + 01
Location Ch 168.90 m & 808.73m
Size 1.15 x 1.45 m (3’ 9” x 4’ 9”)
  1.45 x 1.45m (4’ 9” x 4’ 9”)
Types of gates Rectangular Gates/ Rectangular Gates
Sill level RL 622.27 m (RL 2041.60 ft)
Discharge(Cumecs/Cusecs) LBC=75 cusecs
  RBC=125 Cusecs

Particulars Left bank canal Right bank canal Branch canal (if any) High level canal (if any) Low level canal (if any)
1 2 3 4 5 6
Take off From It is from left side of the saddle dam It is from right side of the Non over flow section In LBC- No branch canals No No
      In RBC- 1) Hunisehalli branch canal 2) Ujjanakunte branch canal    
Length(km) 23.00KM 16.00KM Hunisehalli branch canal=3.50km
      Ujjnakunte branch canal=7.00km    
No of Distributories 18 17 9+7=16
Capacity of Head (Cumecs/Cusecs) 75 Cusecs 125 Cusecs
Croping pattern As per original paddy As per original paddy As per original paddy
  As per actual garden As per actual garden As per actual garden    
Total irrigated area in Acre/Ha 1164.00Ha 1141.00 Ha (Included in RBC)
           
Taluk/Dist benifited Hiriyur & sira/ Chitradurga/Tumkur Hiriyur & sira/ Chitradurga /Tumkur Hiriyur & sira/ Chitradurga /Tumkur
Lined/Unlined (km) 15.600 km / 16.00 km 0.600km/ 2.50km
Authorised capacity Cumecs/Cusecs 75 Cusecs 125 Cusecs