Fluvial & Wetland Governance: Sacred Hydro-Ecological Management Under Totemic Law

1. Fluvial Ecology as a Living Entity Under Bibbullmun Customary Law

In classical Bibbullmun jurisprudence, a river or wetland system is never conceptualized as inert property or passive natural resource; it is understood as a sentient, living ancestral entity endowed with legal personality and custodial rights.^[1] The complex waterways of south-western Australia—including the Derbal Yerrigan (Swan), Djarlgarro (Canning), Bilya Borrigup (Preston), and Karragarup (Blackwood)—are governed through an intricate network of localised custodial estates (kalla-boodja) that assign specific moort lineages perpetual responsibility for monitoring water flow, water clarity, and riparian ecosystem integrity.^[2] This customary tenure operates on reciprocal stewardship: the river nourishes the people, and the people defend the river from ecological degradation.^[3]

2. Estuarine & Freshwater Weirs: Ecological Engineering & Spawning Protection

The practical execution of Bibbullmun fluvial governance is demonstrated in their sophisticated hydraulic engineering works. Across southwest estuaries and rocky river shallows, custodians constructed monumental stone and timber fish weirs (mungah or karda mungah).^[4] Unlike colonial nets that clear entire fish stocks indiscriminately, Bibbullmun fish weirs were designed with deliberate gaps and tidal spillways that allowed juvenile and gravid fish to pass freely upstream to their freshwater breeding grounds.^[5] Harvesting was permitted only at specified seasonal intervals, primarily during the late summer (Bunuru) when tidal currents pushed shoals of mullet (kalkada) and cobbler (yoornan) into shallow bays, ensuring that total extraction never exceeded the population's reproductive capacity.^[6]

3. Wetland Interconnections: The Beeliar & Derbal Yerrigan Chains

The coastal plain of south-western Australia was historically characterised by expansive north-south linear chains of interconnected wetlands, known to the Beeliar and Mooro clans as vital seasonal food corridors and spiritual highways.^[7] Customary governance mandated that fringing reeds (Typha domingensis / yandjidi) and paperbark fringes (Melaleuca) be strictly protected from uncontrolled fires and siltation.^[8] During the wet winter (Makuru), clans relied on wetland chains for waterfowl hunting and bulb foraging; as waters receded in summer, controlled mosaic burning was applied only to dry peripheral rushes to promote new tender green shoots for grazing kangaroos, leaving the central peat cores unburnt to protect subterranean aquifers.^[9]

4. Contemporary Co-Management & Legal Personhood Precedents

Colonial urbanization resulted in the catastrophic draining, infilling, and channelizing of over 80% of southwest wetlands, creating widespread eutrophication, toxic algal blooms, and groundwater collapse.^[10] In response, Bibbullmun custodial organisations are actively campaigning for the statutory recognition of the legal personhood of southwest rivers, drawing on international precedents from New Zealand (Whanganui River) and Colombia. By integrating traditional totemic fluvial governance into statutory catchment management authorities, custodians aim to restore natural hydrological flows and re-establish sovereign ecological guardianship.^[11]