Sub-surface drainage is often made to overcome surface runoff discharge in case of flooding inundation. But the development of this subsurface drainage technology can be developed as a water conservation model. This innovation can be realized if this technology is used to accommodate springs abundant and used for fish farming so that it caused an economic impact.
This model has been done in Purwantoro-Blimbing, Malang City. In recent years, several spring spots emerge, suspected as positive impacts of conservation village activities in RW 23 Purwantoro, or better known as 3G (Glintung Go Green) Village which is morphologically higher than RW 5. This emergence of springs, unfortunately, is still not utilized by the citizens.
“We are worried that if the rainy season comes, the condition of the existing waterways can not accommodate rain water if it’s already filled with water from the springs. We are afraid of the flood,” said Ageng as the Head of RW5.
Puddle of floods that people fear is reasonable because the condition of the river that runs through RW 5 is already full of sediment/waled and the river bottom elevation is higher than the drainage channel so it needs to be dredged. Considering this matter, the Team of Research and Community Service (LPPM) Universitas Brawijaya through Doktor Mengabdi activity offers a solution.
Headed by Prof. Dr. Ir. Mohammad Bisri, MS as a conservation expert, since 2017 has conducted Doktor Mengabdi entitled IbM Drainage Under Surface to Overcome Seepage Stream in RW 23 and RW 5 Purwantoro-Blimbing Malang. In this activity subsurface drainage build using a combination of PVC pipe and box culvert that accommodate water flow from some spring point in the area.
The 12″ diameter PVC pipe and the 0.5 m wide culvert box are installed along a total of about 200 meters to the main river outlet. The underground culvert box channel is modified so that it can be used for the cultivation of Gurami fish and the like so it is beneficial to the surrounding community. In addition, this activity also provides one unit of Centrifugal Pumps to be used as an emergency pump if the water level in the main river is higher.
“Water conservation activities are very important to be done, the existence of clean water with good quality is very limited, the conservation will slow the flow of water into the surface runoff that will disappear into the river and reservoir outlets,” explained Prof. Bisri.
Although the activities of Doctor Mengabdi is a Community Service activity by LPPM that funded by PNBP Universitas Brawijaya, the involvement of the community takes a very big role.
“Almost all of the project work is done by working together, they help carry material, excavation of land, and demolition of existing channel,” said The Head of Research and Community Service Board of UB Faculty of Engineering, Dr. Ir. Runi Asmaranto, ST., MT. [FT/HUmas UB]
