Dyking has long been a major problem faced by the farmers of the Serpentine–Nicomekl lowland. Initially all dykes were built with hand labour, and some of them reached three feet in height. The first machine–made dykes were put in, in 1898, on the north bank of the Nicomekl from the Semiahmoo Road Bridge, around Mud Bay and up the Serpentine to the Woodward farm and the Semiahmoo Road. The dredge was a floating rig that took material from the river bottom for the construction of the dike.
The first machine–made dykes were put in about 1898 around the mouths of the Serpentine and Nicomekl Rivers. This dredge ws used to build dykes in the Mud Bay area of Surrey, BC in 1901.
Settlers desired to keep out sea water as the salt deposited effectively ruined the soil for several seasons until the salt could be flushed out. To achieve this end the Surrey Drainage and Diking By–law was passed in 1889 for the purpose of constructing an earth fill dam with flood gates at the mouth of the Serpentine River. Trouble arose, however, when a severe storm during the winter of 1890 washed a good portion of the newly-constructed dam as well as its flood gates out to sea. The dam was never reconstructed.
The greatest difficulty in local diking was the maintenance of the sea wall between the mouths of the rivers on Mud Bay. This was largely solved after 1907 when construction of the Great Northern Railway began and the railway assumed responsibility for the sea wall portion.
A major project to end sea-water flooding began in 1910 when the Surrey Diking Commission began construction of cement dams and flood gates to replace the Semiahmoo Road bridges. The Semiahmoo Road was to act as a dike between the control dams on the Serpentine and Nicomekl Rivers. The control dams were not placed closer to the river mouths due to the difficulty in construction, and higher costs due to the wider river mouths. In addition local farmers were unable to agree on the location of inter-connecting dykes.
Private dykes existed both upstream and downstream from the Surrey Diking Commission's control dams. The flood of 1935, resulting from heavy snow followed by five days of continuous rain, caused water to flow through the valley as if it was a single stream, and demonstrated the need for improved diking along the river's headwaters. As a result the Surrey Diking Commission in 1939, with federal government assistance, built forty-six miles of dykes along the rivers and their major tributaries. In the late 1940s, due to extensive flooding below the control dams, the Mud Bay Diking Commission was established. The various diking jurisdictions are illustrated in the accompanying map.
As diking and drainage were improved in Surrey's lowlands they provided greater security for local farmers against financial and physical loss. However, flooding can still occur as it did in December of 1982. The high run off from the uplands, combined with high winds and a high tide can back up the tidal water so that it tops the dyke.