The line between land and sea is arguably our Earth’s most changeable geological feature.
Here a constant battle goes on between the forces causing erosion and accretion, superimposed on great changes in global warmth and sea level over millennia.
This is particularly so at estuaries, where rivers meet the sea.
In its natural untamed form, Galveston Island is one long sand bar and its low lying extremities were particularly vulnerable to storms and sea level changes.
Mainland rivers exiting the bay bring great quantities of silt to the sea and there meet the anticlockwise coastal currents and silt from the rivers to the east.
This tends naturally to maintain the island but results in ever changing navigable depths at natural entries to harbors.
The earliest known maps showing Galveston Island date to the 1721 (French, La Harpe) and 1785 (Spanish, De Evia) when the island was called San Luis and the bay, Galvez.
From the Henry Perry map in 1816 a small section of land at the far northeast end was an island, which Perry named Culebras Point (Snakes Point), separated by a (likely storm washout) channel.
That channel was just beyond the slightly higher elevation bounded by where 6th Street was to be platted 20-plus years later.
The island had a gooseneck shape created by the prevailing currents. A map in 1838 showed the channel was silting up but another had appeared further north.
By 1850 that new channel too had almost also filled but its prior location was clear.
The end of the island continued to be a thin sand spit with the characteristic gooseneck turn to the north and west.
It held this general shape into the 1880s except for a few years when large portions were washed out by storms like the hurricane of 1875.
Another somewhat persistent feature was a small slightly more elevated area that supported mesquite trees on the bay side.
As the importance of Galveston and later Houston grew, a string of major engineering projects were conceived to tame natural forces.
These projects led ultimately to the more managed shape of the far (north) east end today.
One major project was to create jetties to reduce the deposits from the long shore currents, permit inland waters to discharge to sea more efficiently, eliminate the sandbars and overall lead to a naturally deeper shipping channel.
The south jetty also extended to form a breakwater to harden the erodible boundaries of land at the point and Galveston channel and harbor side.
An attempt to construct jetties either side of the channel commenced in 1874, and parts of this survived the 1875 hurricane, but was unsuccessful.
A different methodology was tried starting in 1880 but was again found wanting. But the effects of man’s work on the shape of the East End were beginning to be seen.
A more substantial approach, started in 1887, created the core and line of the jetties we see today.
By 1915 the impact of the south jetty on the shape of the East End of the island was dramatically clear.
Its effect was a gradual buildup of sand creating new land and a widening of the island immediately southwest of the south jetty.
It also tended to permit some buildup of sand and vegetated land on its immediate channel side — the start of what we now call Big Reef.
Another major project was to create a seawall to protect the city after the devastating 1900 Storm.
The first segment started at the Galveston harbor terminus of the south jetty near 8th Street, ran to Avenue D and 6th Street, then westward to 39th along the Gulf of Mexico.
This had little impact on the shape of the far East End, or the “flats” as it was then known, essentially relegating it to being a low lying, mosquito infested no man’s land and a trash dump.
The easterly extension of the seawall was created in two stages starting in 1920 and finishing in 1925, and it partitioned the East End in the manner we see today.
It was during this time that the most significant and obvious present day feature, the long “East End Lagoon “ was created.
The physical nature to the north and south sides evolved quite differently. On the north side, near present day Highway 168, which runs to the Corps of Engineers offices and Coast Guard station, the early creation of a rail bed resulted in the double sloughs that exist at Corps Woods Nature Sanctuary.
Also on the north side, inside containment levees, the land has been gradually elevated with ship channel dredge material.
By contrast, the south side is left at or just above sea level, the shape and major physical features of the East End Lagoon land are now primarily driven by continued accretion, storms, sea level changes and man-made usages.
The lagoon has widened significantly from it origin, a probable result of natural edge slumping and rising sea levels.
Military, realty development and commercial activities have also left their mark, with associated roads, pads, ponds and buildings.
The degree of change in the land north and east of where 6th Street is now is well seen by the overlays of 1850 (pre jetties) and 1915 (post jetties) contours on that of the 2012 aerial.
With the south jetty being such a dominant factor in the taming and development for the East End of Galveston Island, it is important to understand the jetty’s history and development, the next subject in this series.