The Tumana Pumping Station is specifically engineered to protect inland communities by managing floodwaters from Tumana Creek during 15- to 25-year return period flood events, Kazuto Suzuki, a consultant from CTI Engineering Consultants and designer of the facility explained
In a statement sent to media, Suzuki outlined the operational design and key factors governing the facility’s effectiveness in mitigating urban inundation in Barangay Tumana.
Pumping stations such as Tumana function by collecting local street runoff, drainage discharge and water from internal creeks, then lifting and discharging it over dikes and floodwalls directly into the Marikina River.
During heavy monsoon rains or typhoons, as water levels in the Marikina River rise, automated gravity floodgates shut to prevent river water from backflowing into the surrounding neighborhood. Equipped with a combined dual-pump capacity of 5 cubic meters per second, or 5,000 liters per second, the facility provides substantial drainage capacity for a localized urban catch basin, offering significant relief against severe street flooding during intense downpours.
Suzuki noted that while the facility provides strong local defense, its success relies heavily on key operational factors. The system depends on clear internal drainage channels leading to the sump pit, as well as strict control over siltation and garbage accumulation, which can drastically reduce pump efficiency. Additionally, prompt operation is required the moment the flap gates close to ensure seamless water removal.
While localized pumping stations manage inland runoff, Suzuki emphasized that comprehensive flood control requires upstream containment to prevent flash floods along the Marikina River.
Referencing Japan International Cooperation Agency studies for the Pasig-Marikina River Basin, Suzuki highlighted the rainy-season operational protocol for the Upper Wawa Dam.
Under this protocol, operators execute a pre-emptive drawdown operation level of 7 meters, lowering water levels from Elevation 135 meters to Elevation 128 meters, to create the necessary storage capacity for incoming flood surges.