Contents preface (VII) introduction 1—37

6.5.2.1. Types of Maintenance
Maintenance works include operations performed in preserving system and facilities in good or near-original condition. Repairs are part of maintenance. Maintenance can be of the following types (29):

1.	Normal	— usual; done annually
2.	Emergency	—	done under unusual conditions affecting adversely the safety of the
			system.
3.	Deferred	— routine/normal ones deferred because of shortage of funds/machines,
			affects adversely hydraulic performance.
4.	Catch-up	—	programme that takes care of deferred maintenance

MANAGEMENT OF CANAL IRRIGATION IN INDIA	247
5. Preventive	— takes care of the causes creating the maintenance needs when they
	are only minor

6. 
   Rehabilitation — renovation needed due to accumulation of deferred maintenance ;
   

otherwise, only for ageing structures

7. 
   Modernisation — updating/improving the system to meet enhanced social, technical,
   

economic activities.

8. 
   ‘Walk-thru’— two or three individuals walking along canals, taking notes on
   

maintenance needs

9. Special — due to unforeseen mishaps such as breaches.
6.5.2.2. Maintenance Policy
The maintenance policy should include directions on

• 
  degree to which preventive maintenance is to be relied upon
  

• 
  appropriateness of deferring maintenance of components for which plans have been approved for rehabilitation or modernisation
  

• 
  relationship among maintenance, rehabilitation and modernisation
  

• 
  using improved technology for maintenance
  

• 
  transparency of maintenance
  

• 
  involvement of water users, and
  

• 
  execution of maintenance