4.4.1 Flood water

The torrential flood received in the plains is unpredictable both in time and magnitude. To effectively use the flood for agriculture and minimize the conflicts amongst the spate communities, certain rules were devised. The documented rules of water distribution are locally known as the Kuliyat and Riwajat-e-abpashi (formulae and customs for irrigation). The spate irrigation of D. I. Khan and D. G. Khan was first documented by the British Revenue administration in 1905 in the form of Riwajat and Kulyat-e-Abpashi [41]. These rules are still being followed. These rules follow the head-to-tail rule which is locally called as the saroba and paina. The earthen dams are built in the main riverine and used for diverting water. The upstream area irrigates their land first, and when the whole field is being irrigated, the earthen dam is breached. Kuliyat and Riwajat mainly emphasize on the following main points as discussed by [41]:


The water rights rules in the spate systems of Dera Ismail Khan and Dera Ghazi Khan under the Sulaiman range in Pakistan were prepared by the revenue period during the British colonial period. The major work was done by Mr. HN Bolton during his tenure as deputy commissioner in 1908. This system was considered as an important source of tax; therefore the Revenue Administration had interest in the system. Also the water distribution right provided an opportunity to resolve the conflicts and disputes amongst the people [28]. The rules were enforced by the Rod Kohi department. The Kulyat Rodwar has these rules written in a register having

## Spate Irrigation: Impact of Climate Change with Specific Reference to Pakistan DOI: http://dx.doi.org/10.5772/intechopen.85889

information of all the villages, labour and also the land. Also an official was responsible for the execution of these rules, urging the farmers to rebuild the embankments and plug the eroded gullies. As according to the flood water distribution rules in Pakistan in the main riverine, the concrete structure is not allowed. Only the earthen structure is allowed; the Department of Agriculture Engineering used to provide the machinery as bulldozers, etc. for the construction of large structure which were strong enough to face the strong flood, but after the closing of agriculture engineering department, the farmers construct the structure on their own through contribution. The place for construction of structure is already demarcated; they are constructed each year on the same place. As floods are unpredictable, often the structure in the upstream is not built at proper time, so the floods make their way to the mid-stream and tail. Also the surplus water is allowed to flow to the tail after breaching of the structures. The amount or depth of irrigation to be applied is not confined; usually the farmer shows voracity in water storage, which leads to breaking of bunds, and sometimes the farmer has to remove the excess water so that the soil may come to field capacity on time for sowing of crops. In the spate irrigation rules, the farmer is allowed to irrigate for the second time if all the other fields in the area have been irrigated. But factually it is not practiced, because the influential irrigate sometimes more than two times while the tail area does not receive a drop of water. Also the number of irrigation depends on the amount of water being received after the flood. As the climatic pattern is changing, the floodbased system is also changing with severe floods in some of the years and drought in other years. The conflicts may become even worse due to water distributions with change in rainfall and flood patterns.
