The Irrigation Engineering and associated sciences are all the while engaged in finding better solutions to overcome the deficiencies listed above. On this background, it is interested to understand the innovative measures adopted in the command of few irrigation projects in Maharashtra. They replaced the open channel water distribution network with innovative specially designed gravity flow PVC pipe water distribution network to resolve the above problems. On the other hand, their system has inbuilt effective and simple water management. They have brought revolution in irrigation sector. A light is thrown over such innovative Case studies situated in different parts of Maharashtra State.
2.1 Jai Malhar Water user Association, Indore Minor Irrigation Project, Dist: Nasik
It is established in the command of Indore Minor irrigation Project, 22 km away from Nasik city. The command of the project was 157 hectare. Before implementation of the innovative PVC pipe conveyance and water distribution network, only 20 to 30 hectare area was getting the irrigation benefit as there were huge conveyance losses in the conventional open channel water distribution network. Beneficiaries were fetching problems to survive as their farm income was very low due to lack of irrigation support. Very few farmers in the head reach were getting the benefit. Tail Enders was deprived. To maximize the benefit and equitable distribution of water, the WUA discarded the use of open channel and established an innovative water conveyance and distribution PVC pipe system.
2.1.1 Innovative Water conveyance and distribution technique A jack well of three meter diameter is constructed inside the reservoir. Two submersible pumps of 25 HP each are installed inside the jack well. The discharging capacity of each pump is 50 liter per seconds (lps). The water is lifted, conveyed by a rising main PVC pipe of 315 mm diameter, delivers it in to the main distribution chamber, constructed on a higher elevation than that of Tank bund level. The diameter of the distribution chamber is 3 meter and the depth is kept as 2 meter. 115 PVC pipe pieces of 63 mm diameter and 300 mm in length are fixed over the vertical wall of the chamber exactly at same level as shown in figure 1. These pipes works as pipe out lets. There number is equal to the number of shareholders. The 100 lps water delivered inside the chamber get divided equally among the 115 pipes and 0.87 lps water flows out from each pipe out let. Discharge of one pipe outlet is assigned to one shareholder. The shareholders are divided in to various groups. A group has 3 to 11 members. Peripheral compartments for each group are formed as shown in the figure below. Each compartment receives water from 3 to 11 pipe outlets depending upon the members of that group. Bhalage (et al 2009).
2.1.2 Zero water loss in Conveyance network and equitable water distribution It is clear that all peripheral compartments receive water proportionate to the no of shareholder in that group. Let, there is one group of 4 members, then the water collected in the compartment form 4 pipe outlets is then conveyed through a common pipe line at the cost of that group, up to the secondary distribution chamber constructed at a suitably located common point of that group. Cost of pipe line is saved due to group formation. The secondary distribution chamber has same number of pipe outlets ( i.e 4 in the case under consideration) fixed over is vertical wall. The water collected in this chamber is equally divided among the four pipe outlets and flows out from each pipe outlet fixed on the vertical wall of the secondary distribution chamber. The water coming out from each out let is then collected in individual compartment/chamber; and is conveyed to the individual’s field. Many of them have made an arrangement to collect it in their open dug well. Thus all the share holders will get equal quantum of water at the same time, thus partitions like head, middle and tail reach farmers is avoided. As the water is conveyed through PVC pipe, except the water loss in broken pipe till the time of repair, there is no loss. Every group has a group head. He is authorized to solve the dispute among them if arises. Due to involvement of people’s participation, the scheme runs smoothly as the powers and responsibility are decentralized. It becomes possible to produce export quality grapes and vegetables. The tactic enables them to adopt advance irrigation techniques such as Drip and Sprinkler irrigation. The water use efficiency is more than 8o to 85%.