This was an important point. As land speculators, the Allens knew that a town rooted in commerce had the best chance for fast growth. The faster the growth of the town, the sooner they could cash in on their $5,000 investment by selling lots.
Harrisburg, some six miles or so downstream, was the major port during the pre-republican period. By establishing a port farther upstream and closer to the interior of Texas, John and Augustus Allen sought to capitalize on the setback that Harrisburg suffered when it was burned to the ground by Santa Anna on his march to San Jacinto.
The race to create to the shipping center of the new republic began in the late summer of 1836 as Gail Borden surveyed the townsite of Houston and the Allens declared it as the place where steamers from New Orleans would unload the fine goods of the world for Texas. Houston was the head of tidewater and a port accessible by ocean-going steam ships.
The head of tidewater was significant because the tidal flow meant that there would be a reliable depth of water in the bayou for shipping.
Whether the junction of White Oak Bayou and Buffalo Bayou was actually the head of tidewater was a subject of debate during the intense competition of the mid-1800's. When dredging of the bayou became the common practice, the point was moot.
Today, the point at which the tidal influence occurs is a few hundred yards upstream of the Shepherd Drive bridge. Early in the twentieth century, the gauge at Waugh Drive measured the tidewater, but the subsidence that has occurred in the last fifty years has caused the U. S. Geological Survey to abandon the gauge at Waugh Drive in favor of the one at Shepherd Drive.
The tidal influence on the bayou is easily seen in a comparison of the readings of the Shepherd Drive gauge with the Piney Point gauge which is several miles upstream.
The graph of the gauge height at Piney Point shows a fairly level pattern of stream flow (except where there is a spike due to a rain storm). At the Shepherd Drive gauge (called, somewhat ironically, Buffalo Bayou at Houston), the gauge height undulates in a wave-like pattern, clearly showing the effect of the tide.
Yet, without looking at the graph of the gauges, one would not even be aware of this tidal effect. The tidal influence on Buffalo Bayou, which was such a critical factor in the establishment of the city of Houston, is today just an interesting curiosity