IO – Supporting President Joko Widodo’s government policies to maintain national food security, Minister of Public Works and Public Housing (PUPR) Basuki Hadimuljono said the government is now focusing on building 61 new dams, a target to be completed by 2024. At least 16 dams have been completed since 2014. In 2020, the Ministry of PUPR has completed construction on two dams, namely, the Tukul Dam in Pacitan and the Tapin Dam in South Kalimantan. The Tukul Dam has a capacity of 8.68 million cubic meters, to supply 600 hectares of irrigation and 300 liters of raw water per second. Meanwhile, the Tapin Dam has a capacity of 56.77 million cubic meters for irrigation water supply covering an area of 5,472 hectares.
Basuki said the project of building 15 new dams was planned to start again in 2021. The Ministry expects to continue the construction of 36 other dams not yet completed, targeted for 2023 at the latest. The construction of these 36 dams will be completed in the 2020-2023 period, for an average of nine dams per year. Inasmuch as dam construction takes three to four years, budgeting schemes for dam construction extend over multiple years. “We propose no new dam construction because we expect to be rather busy on the fourth-year with the presidential election. Our new dam construction will start again in 2021 while still completing the 36 dams,” he explained.
Basuki said that the management of water and irrigation resources would be continued to support sustainable agricultural production; there is also the potential for raw water, energy, flood control, and tourism, which will foster the local economy. “The dam construction was followed by the construction of the irrigation network. Thus, a dam that is built at a high cost can be beneficial because the water will certainly flow to the farmers’rice fields,”he said.
According to Basuki, if the construction of 61 dams is completed within the next 4 years, the water supply to the irrigation network will increase by around 19 percent or as much as 1,169 ha. That way, all of these reservoirs will increase the cropping index as well as agricultural production to support the national food security program. This will make up for the fact that until now agricultural activities still depend a lot on irrigation systems. “Irrigation and agricultural areas alone depend on rain. For irrigated or agricultural areas it only rains 100 percent. This means that it is harvested once a year because it depends on rain,” he explained.
Meanwhile, with the ones that rely on a run-off irrigation system, production can be increased by 120-150 percent. This will be maximized by using the dam as water storage so that the production rate can go up to 200 percent. “But with a dam, it can increase 200 percent or more. This means that in March- April and September-October it can be planted more than twice. If it is more than twice, it means that agricultural production can be increased,” he said.
The Pidekso Dam, which was worked on by the Bengawan Solo River Basin Center (BBWS) is one of the National Strategic Projects (PSN) in the field of water resources to realize national water and food security. “This multifunctional dam with a capacity of 25 million cubic meters is planned to be able to irrigate an irrigation area of 1,500 hectares. The irrigation water from the dam will increase the planting intensity from 133 percent (2000 ha) to 240 percent (3600 ha). It is hoped that the completion of this dam will encourage economic recovery after the Covid-19 pandemic, especially in the agricultural sector,” explained Minister Basuki.
This dam, located in the upper reaches of the Bengawan Solo River, also has the benefit of providing 300 liters per second of raw water in the districts of Wonogiri, Sukoharjo, Solo City, and their surroundings. Its hydroelectric potential of 0.5 MW will be useful; the Dam is very much needed as a flood control mechanism and as a conservation and tourism area, so that it can help improve the welfare of the surrounding community.
Head of BBWS Bengawan Solo Agus Rudyanto said that after the completion of phase I construction, currently a tender process is being carried out for the construction of phase II. The entire dam construction target will be completed by 2022. “For the construction of phase, I which has been completed in the form of road access, dam cover building, circumvention tunnel, and the river diversion process has also been completed. In stage two, the construction of the dam body and complementary facilities will be continued, as well as the dam’s electrical hydromechanical instrument,” he explained.
Construction of phase I of the Pidekso Dam was carried out by the contractor PT Pembangunan Perumahan (PP) with State Budget amounting to IDR 436.9 billion. Furthermore, it is estimated that the second phase of development will require a budget of IDR 376 billion.
The reservoir, with the upright core random fill-type has a spill way on the left side of the dam. The spillway section is divided into 4 zones, namely, the inlet zone, transition zone, chuteway zone, and channel carrier zone. The main dam height of this dam is 44 meters, the peak width is 10 meters, and the total crest length is 383 meters. (dan)