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States should impose a permitting process for dams so as to have a direct role in the planning and implementation of regulations. For dams that have not yet been built there are many steps that can be taken to minimize the impacts. First, efforts should be extended to maximize energy and water efficiency as much as possible; in the past, increases in technological efficiency, recycling, enforcement of environmental legislation, and industrial minimization of intensive water use resulted in a water consumption rate increase much lower than the population demand pressure (WCD). This can be seen as a cost effective method, considering that large-scale dam projects require an incredible amount of capital and are usually both over budget and are completed later than scheduled (WCD). However, if a dam is definitively needed, research should be thoroughly conducted to determine the environmental impacts. The World Commission on Dams reports that many of the negative impacts from dam construction resulted from complications that were unforeseen; it predicts that use of environmental impact assessments could significantly lower these effects (WCD). A State should consider requiring the implementation of these assessments for any project proposed within the permitting process. Furthermore, proper placement of dams (such as on tributaries rather than on a main branch) and the use of minimal numbers of dams on a given river (because multiple dams can have cumulative effects, such as the dams leading to the Aral sea, which decreased water flow to such an extent that an increase in salinity and pollutants caused the entire fishery to collapse at a cost of approximately $1.25-2.5 billion per year) should be legislated by governments as these restrictions can minimize the large-scale negative impacts of large dams (WCD). Once these data are collected, the dam planning may begin; in this way, the dam design can take into account such features as gates that allow managed flood releases on a scale that can mitigate effects to the ecosystem; the permit for dam construction can require these provisions. The use of such managed floods in Kenya has been economically favorable by maintaining sectors of the economy that relied upon flows that would have been blocked entirely by damming (WCD). These floods help to release nutrients and sediments and help lessen the impact of the dam overall (WCD). These managed floods should be tailored to a specific river, as flood cycles are highly unique. It is important, however, that all such planning occurs before dam construction, as post-construction mitigation techniques have not been shown to be effective; the WCD reports rates of 20% effectiveness. It is possible that the IFIM (Instream Flow Incremental Methodology), as described earlier in (LINK TO WATER QUALITY ASSESSMENT AND LEGISLATION) could be used to help predict the effects of a dam and the effects of controlled flooding. !damphoto.gif!Source: USGS
In terms of fish passage, fish passes have a very low success rate currently. In Norway, fish passes report a 26% rate of "good efficiency" and 32% of no success at all (WCD). In many parts of the world, fish passes are not used at all. Also, even with fish passes, fish often suffer from a lack of environmental cues (like currents) that help them find their spawning site (WCD). However, properly designed fish passes (specific to each dam and species of intended use) do hold promise; in Pennsylvania, fish passes were ineffective until tailored to the American shad, at which point they became very helpful in shad restoration (Richardson). Fish hatcheries and stocking may also be required to augment populations until the spawning routine is re-established with the dam in place; successful restoration of American shad and striped bass required such measures (Richardson), and these methods are likewise advocated by the WCD. The creation of artificial wetlands around shallow dam can also help mitigate dam impact by providing new habitat (WCD). Our recommendation is for governments to require dams to create a fish pass specifically designed for that river and its species or to pay a yearly fee to the government which can be used for species restoration and research; the law can stipulate these provisions if the company wishes to operate.
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