Location (Barangay/District): Ayala District, Zamboanga City

Exact point for planning: 6°57'41.11"N, 121°56'42.21"E(near the Ayala River floodplain; flat agricultural surroundings). 

The land area available for the pond system design is assumed to have a planning footprint of 2.0 hectares. This includes approximately 1.6 hectares allocated for the water surface distributed across multiple ponds, while the remaining 0.4 hectares will accommodate essential infrastructure such as dikes, inlet and outlet canals, a settling pond, and a storehouse. The rationale behind this assumption is that there are plenty of contiguous farmland pockets located west of the city proper around the Ayala area. Parcels near the Ayala River are commonly used for agriculture and are suitably sized for smallholder or cooperative pond systems.

Site constraints for the pond system include seasonal flooding risks along the Ayala River corridor, necessitating the design of freeboard, spillways, and emergency bypass channels, with local studies highlighting similar flood issues in city rivers such as Tumaga. The system must also address potential dry-season low flow by sizing the reservoir and settling pond to meet at least 7–10 days of water demand. High silt load and turbidity during monsoon events require the installation of a silt curtain at the intake and a two-cell settling pond for effective sediment control. Possible salinity intrusion may occur in the lower river reaches during the dry season due to proximity to the coast, so measuring electrical conductivity and salinity at neap and spring tides is recommended before finalizing the species mix. Additionally, necessary permits and clearances, including water abstraction permits from the National Water Resources Board (NWRB), permissions from the Local Government Unit (LGU), and verification of land tenure, must be secured. 

The site offers reliable surface water access from a classified river near existing farm communities, which simplifies the intake system and pond operations. The flat topography of the floodplain helps reduce earthwork volume and dike construction costs. Likely clay-rich alluvial soils provide good conditions for low-seepage earthen pond construction with moderate compaction effort, although this should be verified through field tests and referenced with BSWM soil mapping in the portfolio. Road access from Zamboanga City proper to Ayala, approximately 17 kilometers west, facilitates convenient transport of inputs and harvested products. Additionally, there is a growing local market for tilapia and catfish within the city and nearby municipalities, supporting the pond system’s commercial potential.