Flood Control
Flood control reservoirs are incredibly important for protecting life and developments located further downstream. This is especially relevant in the case of an on-stream reservoir and dam holding an extremely large amount of water.
As the nearby water-table is raised with the installation of embankments or impoundments that make up a reservoir, the surrounding flood heights will rise accordingly. This will also occur when soft ground is covered by hard surfaces like asphalt, pavement, or other impermeable surfaces due to shrinking room for drainage within the local food plain.
Oftentimes a stormwater pond will be installed in the form of a permanent body of water in the form of a retention pond, or a detention basin only meant to store water for a short period of time. Detention ponds are primarily used in flood-control measures. These are intended to be quickly drained in order to prepare for the next time that they’re needed.
Energy and Power
Conventional Dam Hydropower
In conventional Dam designs, falling water from a reservoir turns a water turbine, creating energy within the generator. This water is carried to turbines by penstocks or constructed channels and then released further down the waterway.
The difference in water level between the headwater and tailwater is the “hydraulic head,” and determines how much potential energy is stored within the water. In Dams less than 35 feet high, the elevation change is small, creating a fairly small head. This requires larger turbines to produce a certain amount of energy.
Pumped Storage Hydropower
Open-loop vs closed-loop. Open-loop PSH has an ongoing hydrologic connection to a natural body of water. With closed-loop PSH, reservoirs are not connected to an outside body of water.
In pumped-storage hydropower, water is pumped from a lower reservoir to a higher one using low-cost or surplus electric power. When the power demand is high, the stored water is released through turbines to produce electric power, much like in a conventional dam. As this energy is created and sold during peak times, it is being bought at the highest price, allowing the PSH to still turn a profit despite consuming more power than it produces.
Recreation
A large, clean, and permanent body of water can open opportunities for swimming, boating, wakeboarding, waterskiing, fishing, bird watching and hunting, and countless other possibilities. The surrounding area can be converted into campgrounds, parks, picnic areas, or other forms of natural recreation. This will require some construction and maintenance, like the installation of boat ramps, piers, picnic tables, and/or hiking trails.
Income-producing ventures in these areas are greatly affected by the accessibility of their features. This can come in the form of parking lots, public bathrooms, low-impact trails, and easy access from nearby roadways.
Fishing quality and the local ecosystem can be improved by stocking the reservoir with native fish species. This can also do serious harm if natural forces are thrown out of balance. Consulting your local or state fish and wildlife agency will be essential to ensuring the ecological health of the reservoir as well as satisfying fishing opportunities.
Fish like to lay their eggs in safe den-like underwater structures, such as rock piles, sand bars, or other shallow shoals. Installing large rocks, tree limbs, or boulders to provide shelter as well as irregular contours in the pond-floor, or nylon mats in the case of some species, will encourage spawning and fish health. Amphibians and young fish will also need to be provided some form of nursery area in the form of shallow water, where they can escape larger fish and other predators.
Water meant for swimming and bathing will usually need to be approved by local State authorities to make sure it meets particular health and safety standards. This will include ensuring that slopes are gentle and accessible, and that the water doesn’t contain pollutants or toxins that could be harmful to humans or pets.
Aesthetics and Landscaping
A body of water is pleasant to look at, adds a unique feature to the scenery, encourages human interaction outside, and from a purely numbers point-of-view: can significantly increase land value. Adding a well-maintained and healthy pond to a yard, neighborhood, or commercial center has been shown to potentially raise property values anywhere from 5 to 15%.
Most design recommendations suggest that the central sightline is perpendicular to the longest dimension of the water surface. This is a very fancy way of saying that the views should be pointed towards the best and biggest sights, usually those that offer a picture of the widest amount of the lake or pond.
For visual flavor and pleasant ambience, moving water can be a valuable addition to a reservoir. This can come in the form of waterfalls or cascades along spillways or outlets. Fountains and sprinklers can also be installed within the pond itself.
