The success of the pioneers' settlements along the San Juan River depended on irrigating parched land, but the river's frequent swings from almost no flow to destructive torrents made it notoriously difficult to use. At Bluff, moving water from the San Juan River up to the higher farm fields required a canal from far upstream, a major engineering and labor-intensive project known as the Bluff ditch. The Hole-in-the-Rock pioneers regarded irrigation from the San Juan as their greatest challenge, greater even than the journey to Bluff, and every able-bodied man began work on the ditch the day after arriving. Even when completed, its banks often broke, sediment had to be dredged constantly, and river currents repeatedly washed out its head, so that by the end of the first summer it was considered a complete failure. The settlers persisted, and through the fall and winter of 1881-1882 they built a longer, stronger ditch five miles long, six to ten feet wide, with banks up to six feet high. Getting water into the ditch without the river destroying its head remained especially difficult, and one solution used on the second ditch was cribbing made from 100 connected log cabin-like structures filled with rocks and extending into the river, requiring thousands of cottonwood logs. Year after year, the settlers devoted every available man-hour to the ditch, only to have river currents undo much of their work. At other San Juan settlements, water wheels based on the ancient Noria design lifted river water into smaller ditches for individual farms, but at Bluff a water wheel could not supply enough water for the five-mile canal and could not be anchored because the river lacked a sandstone base. The largest water wheel on the San Juan River stood at Montezuma Fort, 18 miles east of Bluff; built by William Hyde, it measured 16 feet in diameter and 12 feet wide and could lift 28,000 gallons per hour, and ten such wheels are known to have operated along the river. In 1884, major flooding destroyed every water wheel on the San Juan River and washed away major portions of the Bluff ditch. Although the ditch was rebuilt and remained in use into the 1940s by the few farmers who stayed at Bluff, the pioneers concluded that the San Juan River was impractical for irrigating a major settlement, and their search for better-watered land eventually led to the towns of Blanding and Monticello.