Prefabricated drop spillways for outlets of reclaimed gullied lands

• Published in: Agricultural water management 1994, Vol.26 (4), p.227-237
• Main Authors: Yadav, R.C., Bhushan, L.S.
• Format: Article
• Language: English
• Subjects: drainage; drenaje; erosion hydrique; erosion por el agua; Gullied land; Prefabricated drop spillway; reclaimed land; terre recuperee; tierras rehabilitadas; water erosion
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/0378-3774(94)90010-8

A concept was developed of prefabricated drop spillways for outlet structure of reclaimed gullies. The prefabricated drop spillways were designed, successfully constructed in reinforced cement concrete of 50 mm thick slabs, installed and tested under field conditions. The prefabricated structure efficiently handled peak discharges up to 60% of its designed capacity. The corresponding peak dischange 0.116 m 3/s was produced by 72 mm storm in 1990 which occurred with the highest rainfall intensity of 80 mm/h in the season. The prefabricated spillway of 0.20 m 3/s discharge capacity and 800 mm vertical fall (costing Rs. 1900/unit) was 23% cheaper than in situ constructed conventional structure of brick, sand and cement of equivalent size (costing Rs. 2450/unit). Use of prefabricated spillways for individual terraces is likely to reduce cost on account of outlet construction by Rs. 200 per terrace. Further, by the technology of prefabrication it is possible to construct outlets with the construction of terraces simultaneously. The simultaneous construction of outlets with land development saves fields from reverting back to gully erosion.