The Two Dam Paradox in Sumbawa: Rethinking Irrigation Performance through Pastoral Livelihoods and Institutional Resilience

Large dams are conventionally judged by storage, irrigation coverage, hydropower, and flood-control outputs, although these metrics can conceal redistribution within coupled crop-livestock systems. This critical mini-review integrates international scholarship with an author-provided comparative dataset covering 367 households around the Beringin Sila and Bintang Bano dams on Sumbawa Island, Indonesia. Literature and technical records were retained when their bibliographic identity, digital object identifier, repository record, or responsible-agency provenance could be verified. The case evidence reports a decline in mean herd size from 12.4 to 7.1 head per household near Beringin Sila, whereas the corresponding estimate near Bintang Bano increased from 9.3 to 17.2 head. The contrast coincided with higher purchased-feed expenditure and weaker livestock-oriented collective action near Beringin Sila, while stronger cooperatives and mutual aid accompanied herd expansion near Bintang Bano. These descriptive patterns do not establish dam causality because the baseline was retrospective, panel continuity was not demonstrated, and service delivery changed during the observation period. Nevertheless, the wider evidence supports a coherent mechanism: irrigation intensification may compress seasonal grazing windows and individualize access, while institutions that coordinate forage, labor, security, and markets can buffer transition costs. The apparent paradox is therefore reframed as an infrastructure-institution mismatch rather than a binary contrast between successful and failed dams. A four-domain appraisal framework is proposed, integrating technical delivery, continuity of livestock resource functions, distributional effects, and institutional capacity. Dam governance in dryland crop-livestock regions should protect seasonal mobility, finance feasible feed transitions, connect water-user and livestock organizations, and monitor herd outcomes alongside irrigated hectares.