Kankakee Valley Post, Volume 9, Number 50, DeMotte, Jasper County, 2 November 1939 — Silting Rate Increases In Historic York River [ARTICLE]

Silting Rate Increases In Historic York River

This historic York river of Virginia is an example of the way in which too much land in clean cultivated crops, and land worn out and abandoned because of too much row cropping, may increase sedimentation in a stream. Sediment has been accumulating in the York river during the last 27 years at a rate five times as great as during the preceding 57-year period,' the soil conservation service finds. Carl Brown, geologist in charge of the studies, says this sedimentation is the result of increased erosion on the slopes draining into the headwaters of the river—slopes on which in recent years there has been an increase in land either in cleancultiyated crops or abandoned because of too much row-crop farming. A,comparison of navigation charts prepared by the coast and geodetic survey indicating water depths on the stream in 1857 and 1911 shows that during that 54-year period approximately 5,600 acre-feet of the soil from the watershed settled as sediment in the York river estuary. Sediment accumulated at the rate of more than 100 acre-feet a year. From 1911 to 1938, when scientists of the service made soundings to determine the extent of accumulation, 15,293 acre-feet—s 66 acre-feet a year—lodged in the river bed. In determining the amount and rate of accumulation, the surveyors took water depths at the same points along the river at which measurements were made in 1911.