Far from being a cause of gloom, however, aid workers in Gambella and Addis Ababa praise the regional government for its preparedness.
Gambella's Emergency Preparedness and Response Plan identifies key hazards and actions needed, including procuring supplies - from food rations to female condoms - and allocating responsibilities to state and non-governmental actors.
The region's 300,000 people need this preparedness. Gambella is one of four regions in Ethiopia officially designated as "developing". The low-lying region bordering Sudan is remote, politically charged and poor - even by low national standards.
Conflict from within and without
Gambella's conflict risk is heightened as its neighbour Southern Sudan approaches a January 2011 independence referendum. Associated internal instability and resource-related tensions in Sudan's South have already spilled over into Ethiopia.
In 2009, a large group of Sudanese Lou Nuer crossed into Ethiopia following clashes with another Sudanese group, the Murle. Although cousins of the Ethiopian Jikany Nuer, the better-armed Sudanese Lou Nuer drove thousands of Ethiopian Jikany Nuer off their land in Gambella. The regional government says some 38,000 Ethiopians are still displaced.
Apart from the problems imported from Sudan, recurrent internal clashes over land, natural resources or vendettas among and between local agro-pastoralist Nuer and mainly agrarian Anuak communities have, at least temporarily, displaced some 40,000 people.
In Wanke, a few hours' drive north of Gambella town, inter-clan clashes among different sub-groups of the Ethiopian Nuer forced several thousand families from their homesteads in April. They are staying only a few kilometres away from their homes, and local leaders told IRIN that peace talks could succeed but government involvement in stabilizing the situation was limited. They are living with relatives and friends, have planted almost nothing to harvest and complain of eating wild foods that are not nutritious.
Community leaders told visiting aid workers that food, plastic sheeting, jerry cans and cooking equipment were their priority needs. The International Organisation for Migration (IOM) is working with NGOs to supply such non-food items in one of many ongoing small-scale relief operations in the region where only a handful of international agencies operate.
At a political level, Gambella is described by a well-placed observer as in a state of "uneasy calm". Inter-community tensions in the region are exacerbated by their relationship to the national political dynamic. According to the 2007 census, the Nuer make up 46 percent of the region's population, more than double the 21 percent recorded for the Anuak. A significant slice of the remaining population is not indigenous to the area and known as "highlanders" - regardless of where they come from in Ethiopia. Tensions over access to political and economic influence have erupted before, as in late 2003 when government security forces cracked down after Anuak armed groups clashed with highlanders, leading to allegations of human rights abuses and arbitrary killings.
These tensions, analysts say, could re-ignite. Most recently, the reappointment of the Anuak regional president and chairperson of the multi-ethnic ruling party in the region failed to address Nuer political aspirations, according to some observers. (For a full review of the complex history.)
The possibility of Southern Sudan's January referendum provoking new conflict and instability across the border is regarded nervously. The area hosted over 200,000 Sudanese refugees displaced in the 1980s by the civil war. Many left soon after the Ethiopian regime of Mengistu Hailemariam, a supporter of the Southern Sudanese rebellion, which took advantage of the camps for recruitment and training, was overthrown in 1991. Only some 26,000 Sudanese refugees remain in Ethiopia, according to the UN Refugee Agency.
Beyond the floods
While politics and conflict remain sources of risk, floods are of more pressing concern at present. Before the end of October, the Baro and three other rivers in the region will swell to their seasonal peak, fed by rainfall in the Ethiopian highlands and locally. Gambella floods year after year, but sometimes with positive results. Flood recession agriculture - planting in alluvial soils as the flood waters drain away - is a key production opportunity.
The floods, most recently in 2008, cause deaths, displacement and loss of assets. Riverbank living, driven by dependence upon river water for their livelihoods, leaves much of Gambella's population highly vulnerable to flooding and hard to reach given poor roads, a sparsely distributed population and long distances.
In response to flood risk, as well as the consequences of limited agricultural opportunity and erratic rainfall, the regional government has begun to explore longer-term policy options. The concept of "villagization", whereby families would be grouped closer together on higher ground, with new clinics and schools nearby, is a key initiative. However, one aid worker said implementation would be "very difficult" and questioned the level of community buy-in.
Beyond local government planning, the vast areas of land in the region have attracted interest from potential investors. Companies with links to India and Saudi Arabia have launched commercial agricultural schemes, while oil and gas exploration has not yet yielded publicly declared finds.
Gambella will be facing multiple hazards for years to come. That seems a 5/5 certainty. But in acknowledging its threats, observers say the region has taken an important step towards managing them.