Figure 7.11 Block wise ground water availability

Table 20 Ground water availability

7.53.75 0 7.5 15 22.5 30 Kilometers

Figure 7.11 Block wise ground water availability

Legend

Percolation in ML

20153 - 32775

32776 - 45397

45398 - 58020

58021 - 70642

GANJAM DISTRICT BOUNDARY

7.4.2 Surface Water Availability Surface water availability in Ganjam District is sufficient for irrigation except in few interior pockets of Ganjam district. Manning's methods are used to calculate the flow rate through the soil profile, taking into account the depth and velocity of water flow for different types of soils. Manning's coefficient can be calculated by dividing depth by 0.167 meters.

Method to calculate the surface water

Equation 2 Design Discharge Calculation - Mannings method

Maximum of 30 % of water can be considered from the surface water sources for the usage. Surface water is one of the most important natural resources required for human consumption, domestic purposes, irrigation, industrialization, urbanization etc. The demand for groundwater is increasing every year due to growing population,

recurring drought and increased agricultural and industrial activities. To meet this increasing demand, proper understanding of the groundwater condition in terms of availability and distribution very important.

Table 21 Surface water availability - block wise

The highest surface water availability is observed in the block Jaganath prasad with 4025453.27 ML and the lowest Surface water availability is observed in the block Digapahandi with 23997.51 ML. Digapahandi block of Ganjam district is a chronically drought prone and economically backward area of Odisha. The area requires development of ground water through suitable structures to combat drought and to increase crop yield by covering more areas under irrigation.

7.4.3 Water Demand

Water Demand of Ganjam district is calculated based on Domestic Industrial and Agricultural demand. This helps us to Estimate the current water demand and helps

Table 22 Industrial water demand

to project the future water demand so that the being identified.

Table 23 Domestic Water demand gap is

Domestic water demand is being calculated by considering Urban and rural population water demand as 135lpcd and 40lpcd. These values are taken from CPHEEO. The future demand estimation is calculated by projecting the population using Arithmetic Increase Method. After the Domestic water demand estimation it is observed that the Highest Domestic demand is observed in Rangelikuda with 31614.5 ML and Lowest Domestic demand is observed in Dharakote with 3368 ML.

Industrial demand is calculated based on the scale of the industry such as Micro, small, medium and large scale industries. The water demand for the industries is varied between 45-450 lpcd.

So it is considered that the demand for micro scale industries is 40lpcd, Small and medium scale industries is 135lpcd and large scale industries in 450lpcd. the values are taken from IS 1172:1993 Code of basic requirements for water supply,drainage and sanitation.

After the Domestic water demand estimation, it is observed that the highest industrial demand is observed in the block Begunaipada with 10.89 ML and the lowest industrial demand is observed in the block Chikiti with 2.22 ML.

The Agricultural water demand is being calculated by considering duty, delta and base period of the crop.

Equation 3 Agriculture water demand method

Table 24 Major crops of Ganjam district

The major crops of the Ganjam district are cereals, coarse cereals, pulses, oilseeds, fibres, vegetables, spices and other crops. The duty, delta and base period of these crops is considered from water productivity mapping of major Indian crops.

By using these values, the crop wise water demand is Calculated and then after considering the seepage lose as 25%, Field lose as 20% and canal lose as 1% finally the total annual water requirement of the water in million liters is calculated.

After the demand estimation it is observed that the Highest Agriculture demand is observed in Digapahandi with 96.46 ML and Lowest Agriculture demand is observed

in kukudahandi with 36.33 ML.

Table 25 Agriculture water demand - Block wise

7.4.4 Water Budgeting Water budgeting is a water management tool used to estimate the amount of water a landscape will require. It can be calculated for a single irrigation event, on a weekly or monthly basis, or even annually.

The district has a total area of 402.14 square kilometres. The water budget for Ganjam District is estimated to be 15541130.31 ML/annum out of which 161072.57 ML is Ground water availability and the rest 566085.48 ML is annual water demand.

Table 26 Water Budgeting - gap identification

It is observed from the above analysis Water budgeting, the highest Agricultural demand is observed to be in Digapahandi block. Highest Domestic demand in Rangelikhuda, highest Industrial demand in Begunaipada block. It is observed that the

highest Ground water Availability is in Surada. Highest Surface water Availability in Jagganath Prasad. The highest Gap is identified to be in Jagganath Prasad Block and lowest Gap in Digapahandi.

7.4.5 Ground Water Quality Index Ground water is getting polluted due to various human activities and water logging of waste water from the houses due to improper sewage system for which ground water is contaminated due to seepage from effluent bearing water body.

Water quality Index (WQI)

F o r c o m p u t i n g W Q I , t h r e e s t e p s a r e followed. In the first step each of the parameters has been assigned a weight according to its relative i m p o r t a n c e in the overall quality of water for drinking p u r p o s e. The maximum weight of 5 has been assigned to the parameter chlorine due to its major importance in water quality assessment. Magnesium, which is given the minimum weight of 1, as

magnesium by itself may not be harmful to other. In the second step, the relative weight (wi) is computed from the following equation:

where WI is the relative weight wi is the weight each parameter and n is the number of parameter calculated relative weight (wi) values of each parameter are also given in Table- 04. In third step a quality, rating scale (qi) for each parameter is assigned by dividing its concentration in each water sample by its respective standard according to the guidelines in the WHO and the result multiplied by 100.

Table 27 Weights and Relative weights of the parameters

Equation 4 Water Quality Index

Qi = (ci/Si) x 100

Where qi is the quality rating, Ci is the concentration each chemical parameter on each water sample in mg /l, Si is the Indian drinking water standard for each chemical parameter in mg/l according to guideline of the BIS -10500, 1991. Forth computing the WQI the first is determined

each chemical parameter which is used then the WQI as per the following equation,

Si = WI x qi

WQI= sigmaSi