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HomeMy WebLinkAboutAshland Cr Stream Survey 2000 ^,,&lAlth C,.eek Sf1eeAlII- S"'"ey (Bear Creek to Reeder Reservoir) 2000 It. .. Asblaad Creek, Litbia Park Prepared by SISKIYOU RESEARCH GROUP Greg Bennett PO Box 2550 Cave Junction, Oregon 97523 541-601-8068 ~_...~._...--.__. ......._~, ... ..,... hlflocHHu:tio>> As a service to the community, and with concern for the aquatic organisms residing in Ashland Creek, the Ashland Ranger District and the Ashland Watershed Partnership came together to organize a survey of Ashland Creek. Tioga Resources and Siskiyou Research Group, under contract with the U.S. Forest Service, conducted this survey of Ashland Creek in August JL. -.- 2000 to assess the condition of the stream channel, the riparian and aquatic habitats, and fish populations. We followed a protocol developed and used by the Forest Service. Following is a summary of our observations of Ashland Creek. A more quantitative and technical report of our survey has been provided to the Ashland Ranger District office and is available upon request. Ashland Creek is the centerpiece of the community. It is showcased in Lithia Park and through downtown and ties the two together, providing a focal point for the community and a slice of wildness through an urban setting. AsWand Creek is also a workhorse. It provides the city with clean water, hydroelectric power, irrigation, and recreation. AsWand Creek carries away wastewater and runoff from streets and parking lots. AsWand Creek also provides habitat to aquatic and riparian dependent species like insects, fish, salamanders, frogs, snakes, birds, and . small mammals. Clearly, the health of Ashland Creek is vitally important to the community. A4&lA1d. C1"eek Setti1l.9 The AsWand Creek watershed extends from the old growth fir and hemlock forests of the high Siskiyou crest to the parking lot of the wastewater treatment plant. To illustrate, cup and join your hands with pinky fingers side by side and the tips of the ring fingers touching. This is roughly the shape of the watershed. The tips of the tallest fingers are Mt. Ashland, McDonald Peak, and Wagner Butte. The crease made at the base of your fingers on your right hand is the West Fork of Ashland Creek and on your left hand the East Fork of Ashland Creek, and where they come together at the base of your pinkies is Reeder Reservoir. The seam created by your touching hands is AsWand Creek. Your curved fingers represent the steep and rugged upper portion of the watershed and your pahns the flatter and gentler lower section. Our five-mile survey covered the lower section of the watershed from the mouth of Ashland Creek to Reeder Reservoir. Ashland Creek Stream Survey 2000 Page 1 of "7 '~-,.. ---._''''_~',~-,.. ---,,~-_._.-.,_..-----~,. The geology of the watershed is largely comprised of a unique feature called the AsWand Batholith, a very large and thick lens of volcanic magma that cooled slowly underground creating large-crystalline rock commonly called granite. Over time the overlaying volcanic and sedimentary rocks eroded away exposing the batholith to weathering and decomposition. Soil- stabilizing vegetation is slow to grow in these easily erodable granitic soils. This contributes to ., - J./., -' the fragile nature of the watershed. Sf1-eAm SUM'ey ).let"~" Our survey methods followed a protocol designed to generate data that provide a basic but detailed picture of the stream. We collected information on the aquatic habitats, the riparian vegetation, and the abundance and distnbution offish. We began our survey by consulting a topographic map that aided in dividing the length of AsWand Creek into three sections, or reaches, which appeared to have distinct characteristics from each another. Each reach has a similar theme of pool and riffle types, slope, volume of water, and valley type through which the creek flows. The three reaches identified in AsWand Creek are: ~ Lower Reach - urban/residential reach (confluence with Bear Creek to the Wmbum Way crossing); ~ Middle Reach - Lithia park reach (Wmburn Way crossing to the Granite Street reservoir); ~ Upper Reach - wildland reach (Granite Street Reservoir to Reeder Reservoir). The urban/residential reach flows through a wide valley, the Lithia Park reach flows through a wide V-shape canyon with a flat valley floor, and the wildland reach flows through a narrow V- shaped canyon. Ashland Creek Strean Surwy 2000 Page 2 of 7 ."...-,.".--.....--..--.- , 2000 Ashland Creek Stream Surve " /" ~ ~f.s l:.'.. ,...~ C ~~, rc.." -,_ ,~ ',~ , '6 'e '" \ I / -> r Granite 51. Roes \- 1 I -... n I ' Jl ~ r, \ j I "v/ ~ ';0' '" ;l: ~ ';0' N A 3000 0 r----! r----! 3000 I 6000 Feet 2000 I J-.----I o I 2000 I 4000 Feet I The foundation of the survey is in tJ?e identification and measurement of pool and rifile habitat units. Every foot of Ashland Creek is categorized into these basic units. In addition, special case habitats such as side channels, dry channels, braided channels, culverts, dams, chutes, and waterfalls are identified separately. Collectively, all units are referred to as 'aquatic habitats' and are measured for length, width, and maximum depth (or height in the case of dams and waterfalls). Additionally, an estimate is made on the percent of sand, gravel, cobble, and boulders that are present in each aquatic habitat. When the data is processed for the length of a reach, the information reveals a great deal about the condition of the stream channel and the quality ofthe aquatic habitats. For example, an average pool depth ofless than three feet combined with a high percentage of sand and silt may indicate sedimentation and loss of pool habitat. Sedimentation is the filling in of sand and silt between gravel and cobble, which may smother fish eggs and reduce Ashland Creek Stream Survey 2000 Page 3 cJ 7 ~.............--.,~---., hiding cover for small fish and aquatic insects. This situation would require further investigation at the watershed level to determine causes and solutions. The area adjacent to the stream is known as the riparian zone. This zone is determined by the presence of water and is naturally occupied by water-loving plants. For this survey, the riparian zone width is defined as 100 feet from the stream channel. The vegetation growing -, _ It. _' within this area is known as riparian vegetation and is critical to the health of the creek. Healthy riparian habitat will maintain water quality by shading the creek from the warming rays of the summer sun. Further, large riparian trees provide extensive root systems that stabilize stream banks against erosion and dampen the effect of floods. This process stores and releases water slowly to provide for year-round flow. Large riparian trees eventually fall into the stream creating instream woo~ or large woody material. Instream wood promotes pool formation, provides cover for fish and other aquatic organisms, and traps and holds gravel that is used by spawning fish for egg deposition. Our survey assessed the condition of the riparian zone for species and. size of the dominant overstory and understory trees. Perhaps the most elegant expression of a watershed is fish, specifically, anadromous fish. Anadromous refers to fish that spend their adult lives in the ocean (mostly eating and avoiding being eaten) then return to inland rivers and streams to reproduce and eventually die. Ashland Creek does not contain the large runs of anadromous fish it once di~ but it does contain a small run of steeJhead trout that return to spawn in the lower and middle reaches in late winter and early spring. Our survey of the fish in Ashland Creek consisted of snorkeling randomly selected pools and rifiles and counting steeJhead ofiSpring and resident rainbow and cutthroat trout. Sh-ea. S,,"wey ~e6""(t" Channel Morphology Our observations found most of Ashland Creek to be channelized (confined) by riprap (armoring of the stream banks with large boulders or cement), culverts, roads, benns, and other residential and agricultural practices which encroach upon the stream channel. Historically, flooding of the lower reaches created many low gradient side channels and wetlands that provided ideal aquatic habitat for fish. Channelization focuses water enerw during periods of high flows, so instead of being able to spill out onto the adjacent floodplain the energy of the water is directed Ashland Creek Stream SUNBy 2000 Page 4 of 7 ......._..~--....._~..,...." ','<._."..""'--..............-" "'- downward to cut a deeper and straighter channel. This process reduces the quality and quantity of pool habitat for fish. Pools are important fish habitat for feeding, resting, and escaping predation. A high frequency of deep pools is an indication of quality habitat. Compared to less altered streams, Ashland Creek has fewer and shallower pools. We found that the number of pools has been ., _ ;L. -.' reduced by channelization, and pools are filling in with coarse sand from the decomposed granite of the watershed. The presence of roads, trails, hillslope erosion, urban and residential development, and the sluicing of Reeder Reservoir appear to accelerate this process. AsWand Creek also lacks instream woody material (fallen trees), which play an essential role in the formation of deep pools and large spawning beds. Large woody material is nearly absent in the surveyed section of AsWand Creek. Instream wood provides cover for fish from. predation and can create side channels. Side channels are important habitats because of their lower gradients and slower stream velocities compared to the main channel, and offer fish areas of rest and refuge. Our survey found evidence that instream wood had been removed from the channel. Removal of large woody material keeps culverts free of debris but robs Ashland Creek of much needed structure. Our survey documented twelve culverts in Ashland Creek, all currently free of debris. These culverts do not prohibit fish passage, but are contnouting to the channelization and simplification of AsWand Creek. Riparian Vegetation Development and channelization has led to a considerable loss of riparian vegetation throughout AsWand Creek. This loss is most apparent in the lower or urban/residential reach. The lower reach contains a narrow and fragmented strip of small hardwoods, such as, ash, alders, cottonwoods, willows, and big leaf maples. The urban and residential development and agricultural fields have eliminated most of the mature hardwoods and conifers. This strip provides some shade but lacks the structure and size to adequately protect the stream banks from erosion or provide the channel with large pieces of wood. The riparian vegetation in the middle reach consists of hardwood species of big leafmaple, alder, madrone, oak, ash, and cottonwood, and conifer species of Douglas-fir, ponderosa pine, and incense cedar. The riparian zone in the upper reach, while improved in comparison to the lower and middle reaches, has been affected by the Ashland Creek Stream SUI'\'eY 2000 Page 5 eX ~, ...._~._.,,_. _..____.__.__.__,.., ..u_____.. ._~_.__" removal of vegetation and increased erosion potential from road development, trails, and stream bank annoring for flood control. The middle and upper reaches contain considerably less development in the riparian zone and can be managed for riparian protection and recovery. The establishment of vegetation in the riprap-annored areas would contribute to stream bank protection and enhance the riparian zone while keeping the boulders in place. JL. .. Fish and Other Wildlife While surveying Ashland Creek through Lithia Park several people asked what we were doing. We briefly explained our survey and many people were surprised to leamoffish in Ashland Creek. We would, injest, offer the mask and snorkel for them to use and we're surprised on several occasions when our offer was accepted. WIth enthusiasm they took the mask and snorkel and collapsed to hands and knees to see inside Ashland Creek. They would emerge streariring with water and smiling with secret knowledge gained from first hand experience. There are indeed fish in Ashland Creek! We saw colorful rainbow trout, quick and secretive cutthroat trout, bottom-hugging sculpin, and pugnacious steelhead. Missing, however, are the sleek silver salmo~ or coho, and the local leviathans, the Chinook. In past times all were present, and allegedly in large numbers. Changes in the greater Bear Creek watershed have reduced and even eliminated some stocks of salmon. Our results show the presence of steelhead, rainbow, and cutthroat in small numbers in the lower reach of Ashland Creek. As the aquatic habitat and water quality improves in the middle reach we saw higher numbers of these fish speCies. We also observed fish-eating species such as pacific giant AAl~m~nders, belted kingfishers, great blue herons, and green-backed herons. Presence of these fish predators is an indication of healthier aquatic and riparian habitats. Steelhead are blocked from the upper reach by the Granite Street Reservoir, making Ashland Creek a resident trout stream - primarily cutthroat - for the remainder of the reach. According to surveys conducted by the Forest Service, there is a moderate population of cutthroat and rainbow trout above Reeder Reservoir in the East and West Forks of Ashland Creek. Ashland Creek Strea'n Survey 2000 Page 6 of 7 ,- _"-.-'~"_'_'._~..,-..,~..,,"~._,., ""~'_'W_"""""""'~'_'__'_"W;'___'"~',",., ._....._'..n _. ,..' .....____ ",. ...... ..._---_._.,.._.__.,.__..."..~ Water Quality While this survey was not specifically for water quality, we did note several situations affecting water quality. The highest water temperature recorded was 72<>P coming from a pipe delivering treated effluent from the wastewater treatment plant. This inflow was estimated to contribute 70010 of the flow of Ashland Creek below this point. Water temperature above 65~;' -, - lL - .- has been shown to depress young salmon development. We noted several screen-less water diversions that were removing up to fifty percent of the stream flow and unknown nwnbers of smaIl fish. Nine of thirteen tributaries to Ashland Creek consisted of pipes delivering water from unknown origins. Flood control projects-ongoing during our survey-along Calle Guanajuato and in Lithia Park, were raising turbidity levels. We found trash, broken glass, and discarded tires in the urban/residential reach. The stream segment between Hosler Dam and the drinking water treatment plant was nearly dry as a result of water diversion for municipal supply and power generation. While not flowing into Ashland Creek at the time of our survey, the upper and lower duck ponds are clearly a potential source of degraded water for Ashland Creek. Improving the water quality of Ashland Creek would greatly benefit the aquatic organisms of Ashland Creek and Bear Creek. Sc.c._1IIA1")f From Reeder Reservoir to the confluence with Bear Creek, Ashland Creek flows through forest, park, and city. The highest quality riparian and aquatic habitats are found in the areas of least development. Correspondingly, fish densities and wildlife diversity are greater in these natural areas. Urban and residential development and infrastructure have channelized Ashland Creek and reduced riparian and aquatic habitat complexity. Sedimentation and lack of instream woody material further simplify the aquatic habitats. Additionally, the water quality of Ashland Creek is degraded, resulting from warm water input, water diversions, turbidity, and non-point sources of pollution. Nevertheless, Ashland Creek still supports aquatic and terrestrial wildlife and is regarded as a treasure to the community. Careful management and restoration of Ashland Creek can improve some of the lost complexity, and aquatic and riparian environment of Ashland Creek for all to enjoy. Ashland Creek Strean Surwy 2000 Page 7 of 7