Culverts pique interest of state agencies, property owners

Posted: Tuesday, October 23, 2001

It isn't only vehicular traffic on the Kenai Peninsula that interests the Alaska Department of Transportation and Public Facilities. Clint Adler, DOT research engineer in Fairbanks, said a cooperative effort including DOT, the Alaska Department of Fish and Game and peninsula property owners has its eye on salmon in peninsula streams and how they are affected by culverts.

Using Anchor River and Crooked Creek as examples, Adler said, "Surely, anybody can see that we could be doing a better job in terms of trying to get fish under the road."

The distance between the bottom of a culvert and the surface of the water can be a barrier to smaller fish. Culverts narrower than the streams in which they are used can affect the water velocity and impact the movement of salmon. In other situations, the stream channel may have been altered.

"Many (culverts) will pass adult fish, but it's the little guys that can't get through," Adler said. "The little guys need to go through culverts in order to get to season feeding habitats and, more importantly, they need to find somewhere to spend the winter and get some food and survive."

Citing similar studies done in Washington and Southeast Alaska, Adler said, "We're trying to do something positive."

Since the study began in 1998, with funding from the National Marine Fisheries Service, data has been collected on 68 culverts and approximately 61 bridges, according to Steve Albert, habitat biologist with Fish and Game in Anchorage.

"What we did was inventory all the culverts on roads that were specifically put in to access timber on the Kenai Peninsula," Albert said.

Using the data collected, culverts were divided into three categories, gray for those that were probably not passing salmon but required additional data, red for those assumed not capable of passing fish, and green for those that posed no problem.

"Some were green, but not very many," Albert said. "Most culverts fell into the red and gray categories."

Still in draft form, the data will now be run through computer models to give a clearer, more definitive view of the situation. However, some land owners, like Ninilchik Native Association Inc., already have begun taking corrective steps.

"The new relationship that we have developed with Steve (Albert) has been extremely helpful in our ability to manage our road system," said NNAI's Chief Executive Officer David Duffy.

Since 1988, NNAI has constructed some 150 miles of mainline and spur roads to accommodate the association's logging industry on its 64,000 acres. However, damage done by spruce bark beetles has caused logging operations to decline.

"We're in the process of decommissioning roads and developing a comprehensive land-use plan that includes road management plans to address our corporate responsibilities to manage land in a way that makes sense," Duffy said.

The cooperation with Fish and Game has allowed NNAI to make decisions that meet regulatory responsibilities to protect fish passage, as well as sensible corporate decisions, Duffy said, resulting in a win-win situation for NNAI and regulatory agencies.

Albert and Adler said the data is proving valuable for the individual agencies. Fish and Game is focusing on fish passage, while DOT will use it to develop a statewide protocol for assessing fish passage problems with culverts and to prioritize replacement or retrofit of culverts, Adler said.

Kenai Peninsula Borough roads also are benefiting from the data, according to Gary Davis, the borough's maintenance director. Wanting to replace two bridges that cross anadromous streams with culverts, Davis said he was told by Fish and Game that the bridges were the preferred method of crossing.

"They indicated that their initial impression is that a culvert creates a dark tunnel-type effect, which they feel inhibits the migration," Davis said. "They prefer bridges because it is more natural for the fish."

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