This Initial Soil Erosion Report documents WIEF-Nigeria’s findings of the gully erosion assessment for Ideani Community in
Nigeria. The study evaluated historical and existing environmental factors that have contributed to, and/or are contributing to the existence of soil erosion gullies in Ideani as well as current impacts on the community; and the potential for escalation if not mitigated.
Ideani town is located in Idemili North Local Government Area (LGA) of
State in the Southeast geopolitical zone of Nigeria. The town has a land area of 8.938 sq. km. with a population of 18,194, and is essentially of suburban setting comprising predominantly of residential homes and agricultural lands.
Ideani lies on the lowlands of the eastern slope of the
Range. The town receives most of the stormwater runoff from the neighboring upland towns of Uke, Abatete and Umuoji in addition to the stormwater from its own footprint. With a regional gradient of up to 40% in some areas, stormwater flows into Ideani through both surface runoffs and subsurface water creeps. The soils of Ideani are typified by weak lateritic and sandy materials that are unstable and poorly consolidated. These lateritic and sandy soils are easily eroded by storm water runoffs. Ideani soils are generally oversaturated during extended rainfall periods as is the case with other parts of the region.
Two active erosion gullies exist in Ideani - one gully located at Urueze village and the other at Oko village of the town. The Urueze and Oko gully heads measure about 15m wide, 10m deep, and about 5m wide, 4m depth, respectively. Because of the region’s topography and hydrogeology, stormwater runoff from higher elevations in the towns of Abatete, Uke, and Umuoji generally flows toward Ideani or the drainage channel along the Abatete-Uke-Ideani state road corridor. The poorly designed and seemingly undersized drainage system of this state road which was recently constructed by the State Government significantly contributes to the propagation of soil erosion at Ideani. The drainage channel frequently overflows at several points during moderate and heavy rainfalls with the runoff making its way toward the erosion gullies.
Several major public institutions and residential structures, including
Secondary School, are potentially at risk of destruction by the continued propagation of the Urueze gully. If aggressive remedial intervention action is not taken, life and property are potentially threatened as the gully continues its expansion with the yearly rainy seasons. Stormwater runoff from the town empties directly into the only stream (Opiegbe Stream) that serves as the main source of portable water to the community. The Opiegbe stream empties into the
River which flows into the River Niger. These two rivers are major sources of portable and domestic water for millions of residents of
State and beyond.
A comprehensive remedial plan that includes the application of non-structural and natural approaches to reduce impacts of stormwater runoff on the Ideani watershed is urgently required. The plan will include activities that redirect excess stormwater or flood along the Abatete-Uke-Ideani state road, conserve natural areas, reduce impervious cover, and better integrate stormwater treatment. Furthermore, the activities must be enhanced through public and community outreach and enlightenment. Public education is essential to ensure sustainability of the gully termination strategy. The three tiers of government, donors, the private sector and the rural communities must all work together on the solutions in coordinated fashion in order to achieve sustainable results.
It is pertinent to point out that the termination of gully processes on a significant scale in the region east of the River Niger will require unparalleled adjustments to peoples’ lifestyle, and the construction industry’s professional outlook. Activities in highway construction and maintenance as well as residential constructions must be altered to prevent or minimize stormwater erosive effects. This can be achieved through close interaction of the affected communities, local, state, and federal authorities together with the private sector working on the scale of the entire drainage basins affected. In essence, the community must take total ownership of its environment.