The Suffolk Scarp is the upper limit of this area. The nearly level coastal plain is crossed by many broad shallow valleys that have meandering stream channels. Most of these valleys terminate in estuaries along the coast. Local relief is mainly about 1 m or less. Average annual precipitation -1,150 to 1,275 mm.
Maximum precipitation is in summer, and the minimum is in autumn.
Rainfall, perennial streams, and ground water provide an abundance of water. Water for domestic, municipal, and industrial uses is obtained mainly from wells. Many soils require artificial drainage before they can be used for crops, but during droughts irrigation is needed on some of the sandy soils. The dominant soils are Aquults and Aqualfs. They have restricted drainage, a thermic temperature regime, an aquic moisture regime, and dominantly mixed mineralogy.