‘Dam’ Tag

Olympus Dam, Estes Park, Colorado – Flood Control, Power Generation

Photo Credit: Alex Mead

Seen here is the Olympus Dam in Estes Park, Colorado near Rocky Mountain National Park. The dam is 70 feet tall and created Estes Lake, 185 acres in size, after its completion. Construction started in the summer of 1947 and the dam is used today mainly for hydroelectric component to generate electricity. This dam uses sluice gates to regulate the height of the water behind it, and they can been seen at the top of the dam. Currently, the center gate of five is the only one open, but during the spring melt the dam can drain near full capacity to keep the water behind it at a safe level.

Sluice Gate

Photo Credit: Karl Jansen

This is a vertical rising sluice gate, which means that a piece of machinery is used to adjust the height of the gate. By adjusting this height, the sluice gate is able to control the water. In general, sluice gates are used to control the level and flow rate of water in a river. When the gate is fully lowered, water could spill over the top of the gate which has the same effect as a weir. Sluice gates are a powerful tool used by engineers to control water in a river, which is especially critical during a time of flooding.

Mountain Dam

Photo Credit: Alex Mead

Seen here is a mountain dam on a river near Estes Park, Colorado. In the United State there are approximately 75 000 dams ranging from massive arch dams like the Hoover Dam or Glen Canyon Dam to small mass acting dams like this one. However, most dams in the United States aren’t hydroelectric dams, meaning they make electricity by passing water through turbines, like the large famous dams everybody knows about. Perhaps as demand for electricity increases these smaller dams will be retrofitted to capture the energy that is present in their reservoirs.

Dam Sluice Gate

Photo Credit: Alex Mead

This is the spillway of a medium sized dam on the Huron River in Michigan. When water is released down the spillway it exits under a sluice gate in the supercritical flow state. Supercritical flow, however, has too high a velocity for the natural river bottom and will cause an erosion issue. To prevent this fast flowing erosive water force concrete blocks, called baffle piers, are added just downstream. This causes a hydraulic jump to occur transferring the flow from supercritical flow to subcritical flow. Subcritical flow is closer to natural river flow and is therefore less of an erosive force. The baffle piers of this dam can be seen under the water about two-thirds up the page.

Cofferdam

Photo Credit: Alex Mead

Featured in this photo is a temporary cofferdam made of sheet piles. This dam is used to keep the water from the Rouge River, the water on the far side of the dam, from flowing into the canal on the near side. Although it is difficult to tell, the water levels are actually quite different on each side of the cofferdam. By holding back the water from the Rouge River, construction crews can perform work on the banks of the canal in a dry environment instead of working beneath the surface of the water.

Dam Discharging Water

Photo Credit: Alex Mead

The dam pictured above is one of thousands of such dams spread across the United States. This dam is used to control the flow of water downstream by limiting the flow of the river over itself. Water volume is regulated by raising and lowering steel doors, called sluice gates, on top of the dam. During normal conditions this dam operates with two sluice gates partially open, but during flooding more gates can be opened to allow more water to pass. It is very important that too much water doesn’t build up behind the dam which could lead to dam failure.

Broad Crested Weir

Photo Credit: Alex Mead

The Sixth Street Dam, or more properly the Sixth Street Broad Crested Weir, is located near downtown Grand Rapids, MI on the Grand River. It was constructed originally to power furniture mills but currently has no direct application. Typically, there is a six to eight foot vertical drop from crest to the downstream water surface but in flood conditions this can be reduced to only two or three. The Sixth Steet Dam is also fitted with a fish ladder to allow migratory fish, like salmon and steelhead, to pass and continue up stream.