Skripsi
Water balance evaluation and irrigation network rehabilitation of the doroampel secondary canal Tulungagung regency / Yhanuar Lazuardy Shahalam
Abstrak
The Doroampel Secondary Canal is part of the Lodagung Irrigation Network and functions to convey water to paddy fields covering an area of 287 hectares. The performance of the Doroampel Secondary Canal is supported by two drainage canals namely Bengawan 1 Drainage Canal and Ngiping Drainage Canal. The Doroampel Secondary Canal has encountered issues in the irrigation water distribution process due to problems related to the canal rsquo s physical condition and water availability. Based on data and field investigations it was identified that four tertiary canal sections have lost their function in distributing irrigation water. As a result 124 hectares of rice fields are not receiving water supply from the Doroampel Secondary Canal. Considering these issues a water balance study is needed to understand the ratio between water demand and availability as well as a rehabilitation plan for the irrigation network to optimize the water distribution process to all field plots. Based on the conducted research the water balance analysis shows that the water availability in the Doroampel Secondary Canal is still insufficient to meet irrigation water demands. The water balance condition indicates a deficit in nine periods. Given this condition an analysis of the flow from the drainage canals is required to compensate for the water shortage. Supplementation from the drainage canals has improved the water balance condition reducing the number of deficit periods from nine to seven. The irrigation canal rehabilitation analysis resulted in a rehabilitation design for four sections namely SR-DA 1 KN (922 m) SR-DA 2 KR (614 m) SR-DA 3 KN (658 m) and SR-DA 3 KR (912 m). The rehabilitation efforts can enhance the irrigation network performance by improving the uniformity of water distribution. However issues related to water availability need to be further reviewed using alternative approaches to ensure that the planning and management of the irrigation system can operate optimally.