Irrigation projects can be classified in five ways: 1. Type of Flow 2. Function Served 3. Scope of Project 4. Purpose of the Project 5. Financial Returns.
1. Classification Based on Type of Flow:
(a) Gravity canal system or flow irrigation system.
(b) Pumped canal system or lift irrigation system.
In gravity canal system irrigation water is obtained from a surface storage. The storage may be of temporary nature (Perennial River) or permanent (reservoirs). The water flows in irrigation canal system directly from the storage under the force of gravity.
In pumped canal system water is lifted from the source to a suitable height and then the lifted or pumped water is taken in the canal system.
2. Classification Based on Function Served:
(a) Irrigation scheme.
(b) Drainage scheme.
(c) Reclamation scheme.
The quantity of water required for any irrigation scheme is very large. As such storage scheme itself is important enough to be recognized separately as an irrigation project.
Drainage scheme helps in maintaining healthy soil conditions. It helps indirectly in crop production. Though benefits derived from such a scheme are indirect it is in no way less important.
Reclamation scheme reclaims water-logged, saline and alkali soils. It is also of indirect but valuable help in crop production.
3. Classification Based on Scope of Project:
(a) Major irrigation project (C.C.A. > 10,000 ha.)
(b) Medium irrigation project (2000 ha < C.C.A. < 10,000 ha.)
(c) Minor irrigation project (C.C.A. < 2,000 ha.)
Previously when the total expenditure on a project was more than Rs 5 crores it used to be called major project. Those costing between Rs 25 lakhs and 5 crores medium and rest minor, owing abnormal price rise this classification is no more valid. Now the projects are termed according to the benefits provided by them.
A small scheme benefitting less than 2000 ha C.C.A. is called minor scheme. It includes tube well as well as surface schemes. Similarly project having more than 10,000 ha C.C.A. is termed major irrigation project. Rests are called medium irrigation schemes.
4. Classification Based on Purpose of the Project:
(a) Single purpose project.
(b) Multipurpose project.
When a project is envisaged to provide only irrigation benefit it is called single purpose project. Some major and medium projects provide other benefits in addition to irrigation. They are then called multi-purpose projects. Other benefits are hydro power, flood control, domestic and industrial water supply, navigation etc.
5. Classification Based on Financial Returns:
(a) Productive irrigation scheme.
(b Protective irrigation scheme.
Productive irrigation project is the one which is introduced with an idea of recovering all the expenditure direct and indirect incurred during the construction and life time of the project. Life of the project is fixed right in the beginning and may be taken as 100 years.
Protective irrigation project is not actually remunerative. Hence this type may also be termed as unproductive irrigation project. This type of project is generally taken up during the famine period or to solve unemployment problem. It helps in giving employment to the cultivators as a means of livelihood during odd times.
Thus productive scheme adds to the wealth of the nation. Whereas, protective scheme is basically a relief scheme.