In 1892, P.J. Flynn, lately executive engineer in the Public Works Department of Punjab and an eminent member of the American Society of Civil Engineers, wrote in his Irrigation Canals, ‘It may be thought that Indian canals are too often referred to in the following pages, but it is as well to remember that the finest examples of canal construction are to be seen there, that in length, cross-sectional dimensions, discharging capacity, number and aggregate mileage, the Indian canals are the greatest in the world, and that their structures are permanent.’

By 1892 nearly 43,800 miles of main canals and distributaries had been constructed in British India, irrigating 13.4 million acres at a total capital cost of Rs. 382.6 million, and returning net revenue annually at a rate of 4 to 5 per cent on the investment. Fifty years later, when the imperial account books were closed, just over half of British India's total irrigation, some 58.8 million acres, was provided by public works, 74,656 miles of main canals and distributaries which served approximately 32.8 million acres, approximately one-quarter of India's total cropped area. Rs. 1,544 million had been expended on the system, at an average rate of Rs. 47 per acre, making the land irrigated by public works the most valuable agricultural land in India. That investment brought in, by 1945–6, an average annual net revenue, in gross receipts less working expenses, of Rs. 138.3 million, at an average rate of Rs. 4.2 per acre.