Elvira soils formed in silty alluvial sediments that commonly overlay stratified loamy or sandy sediments below 40 inches. Mean annual temperature is from about 47 to 52 degreesF, and mean annual precipitation is from 32 to 35 inches. These are the competing Ambraw , Colo , and Sawmill soils, and the Calco soils. These soils occur in the same landscape position as the Elvira series but lack high Fe and Mn concentrations in the solum. Runoff is slow in level areas and is ponded in depressional areas that are not artificially drained.
Permeability is moderate in the solum and rapid in the underlying material.
These soils are frequently flooded. Where artificially drained, they are used mainly for corn and soybeans. Native vegetation was sedges and prairie grasses that are tolerant to wetness. Along some of the major streams in eastern Iowa. They are inextensive.