in the 1923, the u.s. army corps of engineers was assigned to build the initial of a breakwater or "training wall" heading west of brooks island to protect the richmond inner harbor and preserve the deep harbor channel connecting the bay with the port of richmond. again, stone from the quarry at the southern tip of brooks island was used for this purpose. over many years of subsequent repairs and extensions, the training wall grew to about and siltation built up sand flats of about along its length.