Rivers, creeks harmed by floods

Posted: Friday, October 24, 2003

Fish habitats and the general water quality of several Kenai Peninsula rivers and creeks experienced significant changes as a result of two major flooding events last fall, according to one of two reports released Thursday by the Homer Soil and Water Conser-vation District.

Steady heavy rainfall during October and November 2002 resulted in a pair of "hundred-year floods" occurring in rapid succession. According to the 2003 Salmon Stream Monitoring Report prepared for the conservation district by Cook Inlet Keeper Inc., samples taken from Deep Creek showed elevated levels of ammonia, orthophosphate, total phosphate, turbidity, total suspended solids, settleable solids and color.

Changes in stream channels and spawning beds were seen in the Ninilchik River, Deep Creek, Stariski Creek and the Anchor River, most dramatically in the lower reaches of the Anchor River, said Sue Mauger, a stream ecologist with Cook Inlet Keeper who prepared the report. Mauger collects and analyzes data for lower-peninsula streams for Keeper.

"We will not know the full impact of these floods on salmon populations until the runs that were in the gravels as eggs during the fall of 2002 begin to return," Mauger said in a press release issued Thursday by the conservation district.

Mauger was in the field doing research Thursday and unavailable for further comments.

The Anchor River is spawning ground to king, silver and pink salmon, which will spend between two and four years in the ocean before returning, depending upon the species, according to the Alaska Department of Fish and Game.

Water-quality monitoring has been ongoing on the four lower-peninsula waterways since 1998. In its press release, the conservation district said that the largely volunteer-driven effort had documented high turbidity levels associated with 2002 flooding events.

Among other findings noted in the report:

n The Ninilchik River stream gauge showed high stream flows in the fall 2002 floods (as high as 5,800 cubic feet per second on Oct. 24, 2002, and 1,600 cfs on Nov. 24).

n The Deep Creek data showed the highest recorded values for ammonia, orthophosphate, total phosphorus, turbidity, total suspended solids, settleable solids and color occurred on Oct. 30, 2002, and again on June 11.

n 22 percent of the total phosphorus measurements on the Anchor River were above levels suggested by the U.S. Environmental Protection Agency.

Other data revealed that some smaller streams were slower to recover, such as Woodard Creek in downtown Homer and an unnamed stream near the intersection of Kachemak Drive and East End Road.

Six years of water data has allowed scientists to form a useful picture of the ecology of the lower-peninsula waterways. According to the salmon stream report, data from the four major waterways shows that the water quality is "high in general."

However, the report continued, "some measurements for temperature and pH fall outside the ranges set by the state of Alaska to protects its waters."

Elevated temperature levels may pose risks in salmon streams.

Monitoring on the lower streams has revealed that summer temperature levels consistently exceed Alaska's standards for juvenile salmon. Water temperature is one of the most significant factors in supporting healthy fish populations, the district press release said.

Alaska's upper temperature limit for spawning areas, egg and fry incubation, is 13 degrees centigrade. According to the report, that limit was exceeded at the Ninilchik River monitoring site on 56 days 2002, including 35 days in excess of 15 degrees Centigrade during the summer of 2002. The limit also was exceeded during the summer months during 1999 and 2000. Similar situations were recorded over time at Deep Creek, Stariski Creek and the Anchor River.

Temperature can affect incubation, fish metabolism, resistance to disease and the availability of oxygen and nutrients to fish and wildlife, the report said.

Five pH measurements at the Anchor River, which measure the relative acidity of water, were below state standards for protecting aquatic life. That is, the water was too acidic.

Monitoring at the other rivers and creeks also produced occasional pH measurements falling below the state's lower limit.

Also released Thursday was the 2003 Citizens' Monitoring Annual Report, which covers monitoring activities on streams and creeks in the Anchor River and Kachemak Bay watersheds.

Monitoring programs around the state are facing financial difficulties. This year, state officials opted to focus federal grant money on restoration projects on waterways deemed impaired under federal guidelines. The conservation district, Keeper, and other environmental agencies, as well as individual citizens, scientists and resource managers expressed strong concerns. The Kenai Peninsula Borough Assembly, and the Homer and Soldotna City Councils passed resolutions in support of citizen-based monitoring programs as an important part of monitoring efforts.

As a result, said the district, EPA and the Alaska Department of Environmental Conservation are formalizing an agreement on how to set water quality priorities in Alaska. EPA is soliciting public comments on the agreement at its Web site.

Copies of the district's reports are available by contacting the Homer Soil and Water Conservation District at (907) 235-8177, ext. 5, or by downloading at www.inletkeeper.org/monitoring.htm.

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