Lake rehabilitation: A status report

The widespread recognition of lake degradation as a major environmental concern has led to accelerated efforts to better protect and manage lake resources. Where it is too late for avoidance strategies, lake rehabilitation is receiving increasing attention as a natural resources management option. In recent years, a significant number of lake rehabilitation experiences has been documented throughout the world, and many nations and states have embarked upon major lake rehabilitation programsLake rehabilitation is not a ready-to-go technology at this time and still must be regarded as partly experimental. Nevertheless, there have been a number of notably successful lake rehabilitation experiences. Reducing or halting the influx of undesirable materials is the sine qua non for lake rehabilitation. In most successful experiences to date, this has been accomplished by diversion and/or wastewater treatment. A number of in-lake strategies have also been employed to rehabilitate degraded lakes, often as part of an overall restoration plan. Techniques that appear to be most useful include dredging and nutrient inactivation. Several examples of successful applications are noted.Although efforts to rehabilitate lakes have produced a mixed record, there are encouraging results that suggest the viability of this approach. Lake rehabilitation, however, is no substitute for environmental management strategies that provide for protection of lake ecosystems in the first place.