The US EPA describes nutrient pollution as “one of America’s most widespread, costly and challenging environmental problems.” This issue is of significant concern world-wide, with considerable resources now being committed in Asia and Europe to study eutrophication in streams, rivers, lakes, bays and coastal waters and related economic, environmental and human health issues.
The need for detailed plans describing the restoration of impaired waters is widely recognized in developed countries. TMDL studies outline the maximum amount of a pollutant a body of water can receive without violating water quality standards, and an allocation of that amount to the pollutant’s sources. Determining the Wasteload Allocation, the portion of a receiving water’s assimilative capacity that is allocated to one of its existing or future point sources of pollution, is often required in a TMDL study. Numerical modeling is an indispensable component of these studies.
Marine hydrokinetics (MHK) comprises a range of energy technologies for electricity generation from wave and tidal power. MHK installations can require large areas of ocean, which competes with other marine resources and can be detrimental to marine life and habitats. MHKs are often located at the mouths of ecologically-sensitive estuary systems. This can alter the hydrodynamics and salinity of the system and negatively impact animal and plant life.
Environmental regulations require the development and implementation of watershed plans to meet water quality standards and protect water resources. Engineers and regulators working with impaired or threatened waters must undertake watershed planning that considers all stages in the land development process from land use planning through to land development and post occupancy.
Water temperature has significant and systematic effects on biological processes at all levels of organization, from phytoplankton to whole ecosystems. Temperature influences several other parameters and can alter the physical and chemical properties of water such as dissolved oxygen and photosynthesis production. Some organisms, particularly aquatic plants, flourish in warmer temperatures, while some fishes such as trout or salmon prefer colder streams.