When the water elevation is above the base of the wall for extended periods of time, the retained and infill soils may become saturated. This rapid draw down can cause damage to the wall, unless accounted for in the wall's design by increasing the reinforcement length or adding drainage. When the water level drops rapidly, the hydrostatic pressure of the saturated soil against the wall is no longer counteracted by water pressure. By maintaining the lake's elevation and lowering the water level slowly when needed, the owner was able to avoid costly drainage measures.
It was determined that the golf course's lake elevation could be kept constant, except during rare maintenance shutdown times. There was a certain level at which the lake could always be maintained, but during necessary maintenance periods the owner agreed to lower the water level slowly, reducing the risk of rapid draw down.
Since the water level was predictable and controlled, gray straight-face units were used at the bottom of the wall, up to one foot below the normal water elevation. Above the water elevation, beveled concrete masonry units in two sizes were laid in alternating courses. Earthy brown, split-face units add a decorative touch to this high-end golf course.
In total, four segmental retaining walls were constructed at Emerald Lake, with 3,000 units covering 3,500 square feet (325.2 square meters) at an approximate cost of $15 per square foot ($53.82 per square meter).