Ice Bridges and Roads Construction
These activities may require a Fish Habitat Permit (PDF 69 kB).
Ice bridges over fish-bearing water bodies require a fish habitat permit.
Ice bridges are commonly used over streams in many parts of Alaska to access communities, military training areas, timber sales, mining claims, and oil and gas exploration or development sites. Ice is thickened over rivers and streams to allow heavy loads to be hauled across ice that normally would be too thin to support the weight of equipment. Ice bridges are often used to bypass bridges that may be undergoing repairs, may not be rated to support the desired load or may have overhead structures that restrict the height of a load. Ice bridges are often used with winter roads or ice roads to cross streams in areas where no permanent roads are present.
Creation of an ice bridge requires addition of water, or a mixture of snow, ice chips and water to the surface of the existing ice at the crossing location. In streams with a continuous flow during winter or in reaches of streams that are not known to support fish during winter because of poor water quality, water may be used from the stream to build the bridge. Screened intake structures would be required to prevent injury or death to fish as water is pumped. Water withdrawal would generally be prohibited from streams in winter in areas where stream flow stops since the stream freezes to the bottom in places and forms isolated pools that restrict movements of fish (most North Slope streams and rivers).
Monitoring upstream and downstream of the ice bridge may be required to record changes in water quality that may adversely affect fish wintering in these areas. The need for monitoring is determined on a case-by-case basis, depending on the thickness of the ice in relation to total stream depth, the potential for changes in water quality at the site, and the relative use of the area by fish for wintering.
Additional concerns regarding ice bridges include freezing the bridge down to the streambed over a portion of the stream, thereby freezing fish eggs or fry that may be present at the bridge location. Ice bridges may restrict flow and cause scouring under the bridge that may adversely affect fish eggs or fry that may be present.
|Other Permitting Agencies||Related Documents and Pages|
|Alaska Department of Environmental Conservation||Fish Habitat Permit Application (PDF 69 kB)|
|Alaska Department of Natural Resources;
Division of Mining, Land and Water
|Anadromous Waters Catalog
Catalog of Waters Important for the Spawning,
Rearing, or Migration of Anadromous Fish
|U.S. Army Corp of Engineers||Special Areas Permit Application (PDF 134 kB)|
|U.S. Forest Service||Culvert Application (PDF 94 kB)|
|U.S. Environmental Protection Agency||ADF&G Streambank Restoration Guide|
|Kenai Multi-Agency Permitting||NOAA Habitat Restoration|