Very little happened on February 26th, 1836 concerning the siege of the Alamo. However, there is an interesting illustration, using the maps from yesterday. In the bottom map, you can see the mission's water well in the middle of the courtyard. The well was inadequate for the needs of the fort and a scouting party was sent outside of the fort to the East to gather water from the surrounding acequia (irrigation ditch). A common practice of the Spanish most likely brought to Spain during the time of the Arab Caliphate. The Spanish used the practice extensively in the American Southwest, running the ditches around fields and through towns. The San Antonio de Valero Mission had operated farmland to the north and south along the river and had diverted irrigation ditches to surround the fields. There was also a ditch dug around the Mission, as well as one on the west side of the courtyard running north-south.
You can see the irrigation ditches labeled on the first map. Interestingly, if you look at the modern map of San Antonio you can also see that the courtyard ditch followed Alamo St./Alamo Plaza; the Eastern ditch followed 3rd St. to Bonham, then Bonham St. to Crockett; and the Western ditch followed Broadway/Losoya Sts.
This map shows the layout of the village of Bexar, the river and the Mission-fort. The top is East; North on the Left.
Compare to this:
Layout of the fort; compare to the brown outline in the picture above: