Urban water demand, climatic variation, and irrigation-water insecurity: interactive stressors and lessons for water governance from the Angat River basin (Philippines)

ABSTRACT

Climatic variation and intersectoral water competition increasingly challenge the effective provision of irrigation services. This article explores their combined effects on irrigation allocation from the Angat Reservoir (Philippines), where domestic water use in Metro Manila has overtaken regional irrigation as the dominant right-holder. Rules protecting Metro Manila’s large right to water ‘interact’ with dry spells to affect irrigation security in wet and dry seasons. Historically, irrigators were uncompensated because re-allocation’s cause was contested as (1) an unforeseeable climatic event (releasing domestic utilities of liability), or (2) produced by urban demand (requiring compensation). Trade-off rules must be prepared to navigate combinatory effects.

KEYWORDS:

• Water security
• water governance
• irrigation
• climatic variation
• trade-off rules
• Philippines

Acknowledgments

This research emerged from the first authors’ master’s thesis. The work would not be possible without the generous time of farm households in Bustos and staff in various government administrations, including barangays and municipal government in Bustos, the NIA, and the NWRB. We thank Leila Harris, Leonora Angeles, Gilbert Angeles, Julie Ramos, Fronelle Solis, Fernan Tadeo, the Zerriffi Research Group and the EDGES Research Collaborative.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. A large literature has also shown infrastructure benefits to be uneven across categories of social difference and to compromise contributions to sustainability.

2. The Bustos Dam is also fed by the smaller Bayabas River (3 m³/s) (World Bank, 2012).

3. Refers to both El Niño and La Niña events. We focus on El Niño (warm events) in this article but recognize that flooding is also an important agricultural stressor in the region.

4. Bustos is in Zone I (distinct dry and wet seasons).

5. For more information on the socio-economic household data, please see Shah (2015) and Harding et al. (2013).

6. Estimates for NIA and MWSS vary. Tabios and David (2004, p. 111) state that NIA’s original right was 40 m³/s and MWSS’s original water right was 22 m³/s. This still means that NIA held the ‘lion’s share’ of water rights.

7. The NWRB is the government agency responsible for water resources in the Philippines. It coordinates and regulates all water-related activities in the country (including the multiple competing water needs in the Angat River basin).

8. The World Bank (2012) estimates the annual average reservoir inflow, including the Umiray project, at 70.8 m³/s.

9. Non-revenue water is the unbilled water that is lost through pilferage and leakage before reaching the consumer.

10. Since its privatization in 1997 by two concessionaires (Maynilad Water Services Inc. and Manila Water Company Inc.), MWSS has relinquished its role as utility provider and is now a regulator, overseeing the operations of the two concessionaires (Carroll, 2010).

11. Here, MWSS was allocated 46 m³/s, where NIA and downstream needs were provisioned (on paper) at 36 m³/s and 2 m³/s, respectively: allocations exceeded the average annual inflow (69 m³/s) (World Bank, 2012).

12. A study completed by the Japan International Cooperation Agency, CTI Engineering International Co. Ltd and Nippon Koei Co. Ltd (NWRB, 2011, p. 11) suggested ‘irrigation water demand of 19.2 m³ /s (estimated by the Study Team) in Angat-Massim River Irrigation System’. While one might suggest that irrigation supply and demand are evenly matched, our survey results show that irrigation delivery is troubled during critical periods when water is needed.

13. Strong events are those where the Oceanic Niño Index, or the running mean sea-surface temperature (SST) anomaly, is equal to or greater than 1.5 °C. Weak (< 1 °C SST anomaly) and moderate (1–1.5 °C SST anomaly) events also occur.

14. Farmers reported a poor state of securing insurance from formal lenders; most require large collateral (also Bedore, 2011) and often package loans with insurance packages, to the dismay of farmers. Households also reported that the minimum coverage for crop loss from government avenues is not enough to cover investment costs.

15. These data were collected from Malolos City, 13–15 km from the border of Bustos, by the Philippine Disaster Risk Reduction Management Committee.

16. Prior to the onset of El Niño events, which peak towards end-of-year and into the following year, there can be a ‘signal reversal’ from July to September, where above-average rainfall can occur before the drier conditions in the later part of the year and into the following year (Lyon, Cristi, Verceles, Hilario, & Abastillas, 2006). Our data set shows similar results using inflows as a proxy. In July–Sept., inflows during marked El Niño months are 73.29%, 39.18%, and 0.9% higher than their respective La Niña counterparts. Following dry-season El Niño, we see low irrigation releases because we’re below the curve. If La Niña follows, it might be more troubling.

17. We thank an anonymous reviewer for this point in their pers. comm. with an NIA official.

Additional information

Funding

This work was supported by the University of British Columbia [Li Tze Fong Memorial Fellowship]; C.A.R.E. Society; University of British Columbia [Graduate Student International Research Mobility Award]; Social Sciences and Humanities Research Council of Canada [890-2011-0100]; Social Sciences and Humanities Research Council of Canada [766-2013-0104].