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Diversion Screening and Fish Passage Inventory Report for Colockum Creek, Stemilt Creek and Squilchuck Creek (WRIA 40)

Category: Habitat - Fish Passage Technical Assistance

Date Published: November 16, 2006

Number of Pages: 44

Author(s): Tammy Schmidt


Surface Water Diversion Screening and Fish Passage Barrier Inventory

The Washington Department of Fish and Wildlife (WDFW) conducted a comprehensive diversion screening and fish passage barrier assessment for three streams in Chelan County, Water Resource Inventory Area (WRIA) 40, from April to August 2006. WDFW’s North Central Region 2 staff manages this portion of WRIA 40.

The U. S. Fish and Wildlife Service funded the inventory through the Federal Restoration and Irrigation Mitigation Act (FRIMA). This project assessed available habitat on private and public lands downstream of the Colockum Wildlife Area to the Columbia River and addressed two factors limiting anadromous salmonid populations:

  1. Salmonid mortality resulting from contact with unscreened or inadequately screened surface water diversions
  2. Human-made barriers to fish passage

Unscreened or insufficiently screened surface water diversions frequently result in fish injury or direct mortality. Gravity diversion ditches resemble side channels in which juvenile salmonids normally find refuge. Consequently, when diversion head gates are shut, access back to the main channel is cut off and the channel or diversion ditch is subject to desiccation. Impingement or mutilation from inadequate screens (i.e., gaps or oversized screen openings) also increases mortality of juveniles. Excessive approach velocity can draw juveniles into unscreened diversion pipes, where they are mutilated when contacting pump mechanisms, causing costly damage to pumps and disrupting irrigation schedules.

Productive habitat becomes inaccessible for fish migration when human-made structures such as dams, culverts, fords and pipeline crossings become barriers. Unimpeded passage is paramount to obtaining access to suitable spawning gravel and juvenile rearing habitat, maximizing carrying capacity. Resident trout are equally in need of full stream access, migrating upstream or downstream, in order to maximize genetic interchange.

Locations of human-made structures assessed for fish safety and/or fish passage are referred to as sites for this report. Structures existing at the sites are identified as features. A partial list of features affecting fish safety or fish passage includes gravity diversions, pump diversions, culverts, dams, fishways. A site may contain one or more features associated with it. For example, a dam may accompany a surface water diversion or be equipped with a fishway to facilitate fish passage. Stream measurements stated in River Miles (RM) are approximated from the confluence.

The primary goal of this inventory is to assess unscreened or inadequately screened surface water diversions. The secondary goals are to identify fish passage barriers and to assess the potential available habitat gain for each feature. This report summarizes the results from three tributaries to the Columbia River within the Alkali-Squilchuck Subbasin--Colockum, Stemilt and Squilchuck creeks (Fig.1), which lie south of the city of Wenatchee and drain directly into the Columbia River at RMs 450.0, 461.9 and 464.0, respectively (Andonaegui 2001).

Information collected provides a snapshot in time based on 2006 stream conditions. Data obtained from the diversion screening and fish passage inventory and concurrent habitat survey will allow for prioritization for correction of noncompliant surface water diversions and fish passage barriers to ensure compliance with Washington State laws (RCW 77.55.040, RCW 77.55.060).

Stream Selection Criteria

The Colockum, Stemilt and Squilchuck watersheds were selected for study by WDFW Region 2 staff to supplement data contained in the Salmon, Steelhead and Bull Trout Habitat Limiting Factors Water Resource Inventory Report (Andonaegui 2001) released by the Washington State Conservation Commission. Anadromous salmonid utilization has been documented in Colockum, Stemilt and Squilchuck creeks according to the Washington State Salmon and Steelhead Stock Inventory report (SASSI, WDFW 1993). These streams also support resident rainbow/cutthroat and introduced brook trout (B. Steele, pers. comm., 2006).

Low instream flows and desiccation naturally occur in some reaches of Colockum, Stemilt and Squilchuck creeks. In addition, many small tributaries in this subbasin are seasonally dry, transporting surface flow only during storm events and spring runoff. Tributaries lacking flow during the time frame salmonids would be utilizing them were not included in this inventory.

In 2001, Chelan County inventoried adjacent county roads for fish passage barriers. The Washington Department of Natural Resources (DNR) also previously inventoried road crossings contained on their lands. WDFW’s inventory completed data records of previously identified features, if needed, as well as assessed the quantity and quality of potential habitat gain for each barrier. RH2 Engineering, under contract from Chelan County and direction from the Squilchuck/Stemilt Watershed Planning Unit, is currently conducting an assessment of water supply and storage within the two watersheds. The Watershed Plan Report is tentatively due for release in July 2007 (B. Sullivan, RH2 Engineering, pers. comm., 2006).

Colockum Watershed Overview (WRIA 40.0760)

The Colockum Creek headwaters begin at the southern end of Naneum Ridge, traveling east approximately 13 miles (mi) before entering the Columbia River at RM 450.0. Elevation ranges from 5,800 feet (ft) at the headwaters to 550 ft at the mouth. The lower 4.3 mi of Colockum Creek meanders through private ownership surrounded by orchards and pastures. The remaining area is managed by state and federal agencies for timber production and recreation.

Stream flow is primarily from snowmelt and fluctuates from year to year. Flow naturally tapers through the summer months after heavy spring runoff has subsided. Numerous draws in the lower basin input water only during storm events and spring runoff and were not included as productive habitat for anadromous fish species. ESA listed chinook and summer steelhead utilize reaches within Colockum Creek and its tributaries. Resident rainbow/cutthroat trout as well as planted brook trout are currently found throughout the watershed (B. Steele, WDFW, pers. comm., 2006). Barrier correction and restoration efforts could benefit these species as well as Columbia River coho.

Ivy Walker and Kingsbury canyons enter Colockum Creek from the left bank at RM 2.6. Both tributaries experience late summer drying. Ivy Walker Canyon was assessed as non-fish bearing and was not surveyed. Kingsbury Canyon was surveyed to the end of fish use at RM 0.6. Robinson Canyon, another non-fish bearing tributary, enters Colockum Creek from the right bank at RM 2.8.

Colockum Creek splits into North Fork and South Fork Colockum creeks at RM 5.4. The north fork basin area is the larger of the two; therefore, the habitat survey continued along the north fork as the mainstem. SF Colockum Creek, originating at 5,600 ft elevation on the northern slope of Naneum Ridge, is the largest tributary of Colockum Creek, with most of its 6.8 mi2 basin lying within the Colockum Wildlife Area. An unnamed tributary to SF Colockum Creek enters from the right bank at RM 1.2. The last fish-bearing tributary to NF

Colockum Creek enters from the right bank at RM 6.9. This unnamed spring originates at approximately 5,000 ft elevation and travels in a narrow, steep canyon defined by talus slopes.

Colockum Creek was adjudicated in 1913 with no provisions for minimum instream flow (Andonaegui 2001). Water use and permeable soils reduce the amount of surface flow reaching the mouth of Colockum Creek during the summer low flow period. There are no organized irrigation districts operating in the Colockum watershed.

Stemilt Watershed Overview (WRIA 40.0808)

Stemilt Creek lies between the Squilchuck Creek and Colockum Creek drainages on the northwest side of Jumpoff Ridge. Stemilt Creek originates at 6,300 ft elevation at Naneum Ridge, traveling 12.7 mi northerly before entering the Columbia River at RM 461.9. Fish bearing tributaries to Stemilt Creek include Orr Creek (RM 4.4), Little Stemilt Creek (RM 6.8), an unnamed creek (RM 7.1) and Middle Creek, which drains to Orr Creek (RM 2.0). Numerous seasonally dry washes, draining to the lower mainstem, transport water only during storm events and spring runoff. The lower 6.0 mi flow through private agriculture property.

Fish species potentially utilizing Stemilt Creek and its tributaries for spawning and rearing include ESA listed chinook and steelhead. Coho, in addition to other salmonid species, may also benefit from correction and restoration efforts. Resident rainbow/cutthroat trout as well as planted brook trout are currently found throughout the watershed (B. Steele, WDFW, pers. comm., 2006).

The Stemilt watershed was adjudicated in 1926 with no provisions for minimum instream flow (Andonaegui 2001). Claims for surface water diversions date to the late 1800’s with many of those same families residing in the watershed today. The Stemilt watershed is a highly productive fruit producing area within central Washington resulting from years of prudent irrigation water management. As the need for irrigation water increased, storage ponds were created throughout the watershed. Four irrigation districts currently operate in the Stemilt watershed: Kennedy-Lockwood Irrigation District, Lower Stemilt Irrigation District, Stemilt Irrigation District and Wenatchee Heights Reclamation District. A few surface water diversions purposefully transfer water across drainages within the Stemilt watershed and, in one instance, into the adjacent watershed via a network of ditches, dikes and pipes.

Squilchuck Watershed Overview (WRIA 40.0836)

The Squilchuck Creek watershed is the northernmost watershed within WRIA 40, originating near Mission Peak at 6,800 ft elevation, traveling 10.6 mi northeast to the Columbia River. The lower 9.6 mi flow through private property. The upper mile is contained within the Mission Ridge Ski Area and is cooperatively managed by state, federal and private entities. The Colockum Wildlife Area envelops the headwater tributaries.

Fish-bearing tributaries to Squilchuck Creek include Pitcher Canyon Creek (RM 2.1), an unnamed creek flowing through Squilchuck State Park (RM 7.2), Miners Run Creek (RM 7.0) and an unnamed tributary to Miners Run Creek (RM 0.4). Lake Creek at RM 9.7 exceeds the average gradient limit to be considered productive for anadromous fish, however resident fish populations thrive in ponds near the top of the drainage. Numerous seasonally dry drainages transport water only during severe storm events and spring runoff.

Fish species potentially utilizing Squilchuck Creek and its tributaries for spawning and rearing include ESA listed chinook and steelhead. Resident rainbow trout, west slope cutthroat trout and brook trout (planted) are currently found throughout the watershed. Coho juveniles have been found in the lower 0.3 mi of Squilchuck Creek and could also benefit from correction and restoration efforts (B. Steele, WDFW, pers. comm., 2006).

The Squilchuck watershed was adjudicated in 1926 with no provisions for minimum instream flow (Andonaegui 2001). Claims for surface water diversions date to the late 1800’s, with several pioneering families residing in the watershed today. The demand for irrigation water has dictated land use practices as evidenced by numerous points of diversion, as well as the need to transport water from the adjacent watershed, the Columbia River and the Wenatchee River to cover shortfalls. Residential development in the watershed has increased dramatically over the last several years.

Five irrigation districts operate in the Squilchuck watershed: Wenatchee Heights Reclamation District (from Stemilt Creek), Squilchuck-Miller Irrigation, Squilchuck Water Users Association, Beehive Irrigation District and the Highline Ditch. Squilchuck-Miller Irrigation users have senior water rights, providing a continuous water supply despite seasonal changes in stream flow. The Beehive Diversion is located on Lake Creek, which was not included in this inventory. The Squilchuck Water Users Association allows individual surface water diversions to operate to their maximum capacity until natural stream flow drops below a predetermined threshold, at which time the diversions are required to shut down. The Highline Ditch diverts water from mainstem Squilchuck Creek year round (B. Sullivan, RH2 Engineering, pers. comm., 2006).