3003 W CASINO RD BOEING AIRPORT RD ACCESS 2016-01-01 MF Import

� � 6) Provide Passage at Short Cuh•ert A 50 foot culvert (60") at 6''00 feet blocks pas;age by presenting a velocicy barrier , to fish migration. The culvert will either be baffied or hackflooded to allow passage. � 7) Cre�te SpaNring Habitat � There is a 5-600 foot rcach of stream channel just downstream of Seaway Blvd and adjacent to the new ciry of Everett detention pond that has been previously channelized and the bottrm armored with angular rock. This reach needs alteration to improve its value as � spawnir and rearing habitat. We propose that spawning and rearing habitat be crcated in the lower 350-400 feet of the reach by kcying logs into the streambanks to reduce the gradient and adding gravel of appropriate size for spawning by coho salmon and cutthroat trout. The present gradient is about 3%, roughly ten logs will be added to reduce the , effective gradient to between 0.5-1%. Immediately upstream of the spaKming area is a 150-200-foot reach that is impounded � by a small rock dam that creates a in-channel bedload sediment trap. The channel is presently filled with sediment and is passing all bedload directly downstream. We propose that this structure be excavated annually in the fall prior to the spawning season so that it � can function as a bedload sediment trap. Creation of this spawning habitat is dependent upon how the stream interacts with f the new ciry detention pond. During our site visits it was unclear if water is intended to exit the stream and enter the pond or if the flows are designed to remain separate. The preceding element of the mitigation package is predicated on there being sufficient flow in � the spawning area to provide viable habitat. If this is incompatible with the function of the detention pond, this element may be withdrawn from the proposal. 1 Enhancement of spawning habitat for species like coho salmon and cutthroat trout that are typically limited by the availability of rearing habitat, is somewhat unusual. SpawninR habitat enhancement is proposed,as was previously stated, to improve the chances � for establishing self•perpetuating runs of coho and cutthroat. 8) Provide Passnge at btinor I3arricr 1 7'he rock dam listed under the preccding element is a barrier to migration in its present configuration. Minor reclesign is proposed io allow passage of fish, while � maintaining its intended function and preserving its proposed function in trapping bedload. 9) Provfdc Passngc undcr Scaway Bh�d � Two culverts provide passage under the road and they both pose an impassihle barrier to migration (or anadromous Cish. ]t is proposed that the larger culvert be baffled 1 to provide access to approximately 750 lineal feet of strcam channel upstream. This action may not be consistent with a possible water qualiry infiltration system that is being considered adjacent to the 750 feet of stream. Our concern is that tlows may be too low in � I - 27 -