Colusa Basin Drain Watershed Fish Stranding Tour Concept Paper Mike Hendrick and Brycen Swart NMFS

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1 Colusa Basin Drain Watershed Fish Stranding Tour Concept Paper Mike Hendrick and Brycen Swart NMFS On May 31, 2013 representatives from CDFW, USFWS, and NMFS went on a field tour to look at locations in and around Yolo Bypass that are related to the Sacrament River winter-run and Central Valley spring-run Chinook salmon strandings occurring in the Colusa Basin Drain and associated waterways during the adult migration. The goal of the field tour was to identify potential areas of entry into the Colusa Basin Drain, and discuss potential near-term (and long-term) solutions to prevent future fish strandings. Tour stops included multiples sites in the Colusa Basin Drain, Knights Landing Outfall Gate, Knights Landing Ridge Cut, and Wallace Weir. While this tour focused on the 2012/2013 season, empirical evidence and personal communication indicates that this is not a unique situation. Similar incidences are likely to be occurring on an annual basis, though annual severity is unknown. Colusa Basin Drain The Colusa Basin Drain is a man-made facility that collects and conveys flood runoff and irrigation return flows from 1 million acres (1,620 square miles) of watershed and agricultural lands within Glenn, Colusa, and Northern Yolo Counties to the Knights Landing Outfall Gates, where drain waters discharge into the Sacramento River, or if the River is at a higher elevation, the waters flow into the Yolo Bypass through the Knights Landing Ridge Cut. The first stop on the tour was a fish rescue in progress on Logan Creek. Four fish were removed from the creek and placed into a DFW holding tank for transportation to the Livingston Stone National Fish Hatchery (Photos 1 and 2). We also viewed a location where Chinook were spotted at Delevan NWR at the mouth of Hunters Creek. Although dozens of Chinook were seen at this location, only three were rescued and tagged due to an uneven bottom and flows that pushed the fish further downstream (Photo 3). Discussions at these locations included the challenges of fish rescue in the vast Colusa Basin Drain system. These challenges include: a) Water flow needs for fish rescue versus agriculture and wildlife area needs; b) Property access; c) Temperature thresholds and other fish stressors; d) Safety concerns; e) And general vastness of area versus available staff, equipment, and funds. There was also emphasis on the need to prevent Chinook from entering the Colusa Basin Drain watershed, or at minimum, determining a way to create a barrier where any fish that enter the watershed could be more easily rescued. There were short-term solutions discussed regarding ways to prevent Chinook from entering the Colusa Basin Drain at the downstream end of Knights Landing Ridge Cut thus potentially facilitating easier fish rescue at the Fremont Weir. Longer-term solution were also discussed, including a permanent fish barrier structure located on the Ridge Cut that included a fish collecting device to facilitate rescue efforts. 1

2 Photo 1: Fish Rescue on Logan Creek, May 31, Photo by Mike Hendrick Photo 2: Fish Rescue on Logan Creek, Holding Tank, May 31, Photo by Mike Hendrick Photo 3: Colusa Basin Drain Main Channel continues on the right of the photo. Hunters Creek branches off to the left of the photo. During high flows, fish easily pass over the barrier on Hunters Creek. The dam on the Colusa Basin Drain is a flashboard and only in place during irrigation season, thus during winter months, fish can continue upstream unimpeded. Post a rescue attempt at this location on May 14, 2013, large numbers of Chinook were reported in Hunters Creek. Photo by Mike Hendrick, May 31,

3 Knights Landing Outfall Gates Knights Landing Outfall Gates are located on the Knights Landing Ridge Cut Slough, approximately 1,300 feet from the Sacramento River at River Mile 90 (Photos 4 and 5) at the downstream end of the Colusa Basin Drain. Water from the Colusa Drain is released into the Sacramento River through the Knights Landing Outfall Gates. The gates were constructed in the 1930s to reduce flooding in the lower Colusa Basin from Sacramento River backwater as well as providing a drainage structure for the Colusa Drain when the Sacramento River is at lower stages. The outfall gates were updated in George Heise of CDFW gave an explanation regarding the possibilities of Chinook passing through the outfall gates during the 2012/2013 season (see assessment by George Heise for more information, found on page 6). In order to give us definitive evidence whether Chinook are passing through the outfall gates, it was suggested that DIDSON cameras be installed on the upstream end of the outfall gates. The plan is to get these cameras installed prior to the 2013/2014 season. DIDSON cameras (or similar drop-down cameras) have been used to demonstrate presence of sturgeon in Yuba River. If it is determined that Chinook are passing the gates, solutions could include re-operating the flows to prevent passage or other structural fixes to prevent salmon from entering the Colusa Basin Drain at this location. Photo 4: Downstream side of Knights Landing Outfall Gates, May 31, Photo by Mike Hendrick Photo 5: Upstream side of Knights Landing Outfall Gates, May 31, DIDSON cameras could be mounted in the bays seen in this photo. Photo by Mike Hendrick 3

4 Knights Landing Ridge Cut and Wallace Weir Prior to and after visiting Knights Landing Outfall Gates, we visited stretches of Knights Landing Ridge Cut (KLRC). KLRC is an artificial overflow channel that connects the Colusa Basin Drain to the Yolo Bypass. This channel runs from the Colusa Basin Drain and enters the northwest corner of the Yolo Bypass, downstream of Fremont Weir (Photo 6). Wallace Weir is an earthen berm that is constructed annually at the downstream end of KLRC to allow the retention of backwater along the length of the KLRC to help meet agricultural irrigation needs (Photo 7). During low-flow season/irrigation season, Wallace Weir is in place and KLRC cuts across the Yolo Bypass into the east side toe drain of the Yolo Bypass. During high flows, the Knights Landing Outfall Gates are closed and all flows move through the KLRC, over Wallace Weir (it gets blown out), and into the Yolo Bypass, allowing unimpeded fish passage into the Colusa Basin Drain watershed. It was noted that once Chinook enter into the Knights Landing Ridge Cut, there are no impediments to upstream passage into the Colusa Basin Drain watershed. It is suspected that most of the spring-run and winter-run Chinook that became stranded during the 2012/2013 season gained passage when the Yolo Bypass was flooded and the fish swam from the bypass into the Knights Landing Ridge Cut and eventually into the Colusa Basin Drain watershed and continued upstream. Suggested short-term and long-term solutions are to build a structure that prevents fish from passing upstream at Knights Landing Ridge Cut. It was noted that practically speaking, it would be difficult to perform a fish rescue at this location. The preference would be to have a structure that prevents passage and forces the fish upstream to Fremont Weir. In the short-term, a fish rescue could be performed at this location. In the long-term, passage at Fremont Weir will allow Chinook to continue upstream into the Sacramento River. Another solution is to block fish passage further downstream at Lisbon Weir, an agricultural impoundment structure five miles south of the I-80 Causeway. This would prevent further upstream migration into the toe drain/tule canal and into the Colusa Basin Drain. Like the KLRC, blocking fish passage at Lisbon Weir could only occur when the Yolo Bypass is not inundated. Photo 6: Towards the downstream end of Knights Landing Ridge Cut on May 31, Photo by Mike Hendrick 4

5 Photo 7: Wallace Weir. Photo by Mike Hendrick, May 31, Rescue Effort Over the course of a couple weeks in May, approximately 300 salmon were rescued and released into the Sacramento River. Due to the degraded condition of many of the winter-run captured in the rescue effort, there was concern that these fish would not successfully spawn naturally. The total number of stranded winter-run Chinook salmon is unknown, but could be as high as half of this year s returning population. There was concern among the fish resource agencies that such a large percentage of the returning fish would not be contributing genetics to the future population. In response the USFWS, CDFW, and NMFS made the decision to relocate some rescued winterrun to Livingston Stone National Fish Hatchery (LSNFH) to be spawned. This would help ensure that at least some of these genetics would not be lost to the future generation. As of June 7, a total of 48 fish were transferred to LSNFH. As expected, not all the fish have survived until ready to be spawned due to their condition. As of June 14, 18 female and 17 males have survived and spawning is scheduled to begin the following week. 5

6 Assessment of the Colusa Basin Drain Gate Structure at Knights Landing for Potential Passage of Adult Chinook Salmon from the Sacramento River into the Colusa Basin Drain George Heise CDFW This write up describes the conditions and criteria that were used to evaluate the potential for adult Chinook salmon to pass through the subject structure from the Sacramento River into the Colusa Basin Drain (CBD). It provides minimal background and assumes the reader is familiar with the CBD gate structure and the issues of concern. The CBD gate structure regulates flow from the CBD to the Sacramento River near Knights Landing. The structure consists of a concrete barrier wall the CBD canal with 10 round gated openings to regulate flow. Eight of the openings are 66 inches diameter and two are 42 inches diameter. All have a centerline elevation of 21.0 feet and are equipped with a slide gate on the upstream (canal) side and a flap gate on the downstream (river) side. The slide gates allow the water level in the canal to be regulated at an elevation above the river level. The flap gates prevent water from the river passing into the canal when the river is higher than the water level in the canal. The gate structure has concrete slab at elevation 17.0 extending downstream of the gate openings for a distance of about 40 feet, more or less, to prevent bed erosion from the discharge through the gates. The potential for fish passage through the structure was evaluated based on two criteria: downstream water elevation providing sufficient depth over the slab, and; the maximum theoretical water velocity through the gates as determined by the water elevation differential across the structure (head). At a river elevation of 20 feet, there would be 3 feet of water over the slab and the bottom of the gate opening (el ) would be submerged by 1.75 feet. This condition was assumed to facilitate passage of fish through the gate openings. As the downstream water level drops, it was assumed that fish passage would be increasingly impaired. When the d/s water level drops below 19 feet, the depth over the slab becomes less than two feet and the back water depth on the gates is minimal. When combined with high discharge velocity, downstream water elevations below 19 feet were considered to block passage. The burst swim speed for adult Chinook salmon is from 10.8 to 22.4 fps (Bell 1991.) Using the relationship between maximum water velocity vs. head, a water differential across the gate structure of 6 feet will develop a velocity of 20 fps, 4 feet will develop 16 fps, 2 feet will develop 11 fps and 1 foot head will develop 8 fps in the discharge stream. For this evaluation, it was assumed that a head differential less than 4 feet would facilitate passage; 4 feet to 6 feet would impair passage, and above 6 feet would block passage. Combining the two criteria, the following Traffic Light rating was used to evaluate passage potential: Green: Passage likely 6

7 o D/S water elevation above 20 and head differential less than 4. Yellow: Passage impaired o D/S water elevation between 19 and 20 and head differential less than 6, or, o D/S water elevation above 19 and head differential between 4 and 6. Red: Passage blocked o D/S water elevation below 19 and/or head differential greater than 6. Provisional gauge data was provided by DWR for the water levels in the CBD above the gate structure and the Sacramento River at Knights Landing (which is used for the downstream water elevation at the gate structure) for the period from January 1, 2013 to April 24, This data was entered into a spreadsheet (file name: Colusa Drain Gate Head Differential to xlsx, see data table below) and rated according to the criteria above. The results were as follows: 1/01/13 to 1/19/13, 19 days, Green: Passage likely 1/20/13 to 2/02/13, 14 days, Yellow: Passage impaired 2/03/13 to 2/06/13, 4 days, Green: Passage likely 2/07/13 to 2/13/13, 7 days, Yellow: Passage impaired 2/14/13 to 4/02/13, 24 days, Red: Passage blocked 4/03/13 to 4/14/13, 12 days, Yellow: Passage impaired 4/15/13 to 4/24/13, 10 days, Red: Passage blocked End data The daily values for water levels, head differential and passage rating can be seen on the spreadsheet noted above. Note that other factors affecting fish passage such as attraction flow, fish presence, gate operations or fish condition were not considered in this fish passage potential assessment. 7

8 Water Elevation at Colusa Basin Drain Gates at Knights Landing Date/Time Upstream Downstream Head 1/1/2013 0: /2/2013 0: /3/2013 0: /4/2013 0: /5/2013 0: /6/2013 0: /7/2013 0: /8/2013 0: /9/2013 0: /10/2013 0: days 1/11/2013 0: /12/2013 0: /13/2013 0: /14/2013 0: /15/2013 0: /16/2013 0: /17/2013 0: /18/2013 0: /19/2013 0: /20/2013 0: /21/2013 0: /22/2013 0: /23/2013 0: /24/2013 0: /25/2013 0: /26/2013 0: days 1/27/2013 0: /28/2013 0: /29/2013 0: /30/2013 0: /31/2013 0: /1/2013 0: /2/2013 0: /3/2013 0: /4/2013 0: days 2/5/2013 0: /6/2013 0:

9 2/7/2013 0: /8/2013 0: /9/2013 0: /10/2013 0: days 2/11/2013 0: /12/2013 0: /13/2013 0: /14/2013 0: /15/2013 0: /16/2013 0: /17/2013 0: /18/2013 0: /19/2013 0: /20/2013 0: /21/2013 0: /22/2013 0: /23/2013 0: /24/2013 0: /25/2013 0: /26/2013 0: /27/2013 0: /28/2013 0: /1/2013 0: /2/2013 0: /3/2013 0: /4/2013 0: /5/2013 0: /6/2013 0: /7/2013 0: /8/2013 0: /9/2013 0: /10/2013 0: days 3/11/2013 0: /12/2013 0: /13/2013 0: /14/2013 0: /15/2013 0: /16/2013 0: /17/2013 0: /18/2013 0: /19/2013 0: /20/2013 0: /21/2013 0:

10 3/22/2013 0: /23/2013 0: /24/2013 0: /25/2013 0: /26/2013 0: /27/2013 0: /28/2013 0: /29/2013 0: /30/2013 0: /31/2013 0: /1/2013 0: /2/2013 0: /3/2013 0: /4/2013 0: /5/2013 0: /6/2013 0: /7/2013 0: /8/2013 0: days 4/9/2013 0: /10/2013 0: /11/2013 0: /12/2013 0: /13/2013 0: /14/2013 0: /15/2013 0: /16/2013 0: /17/2013 0: /18/2013 0: /19/2013 0: /20/2013 0: /21/2013 0: /22/2013 0: /23/2013 0: /24/2013 0: