Twelvemile Mainstem Instream Phase I and Phase II Restoration Monitoring Plan

Transcription

1 Twelvemile Mainstem Instream Phase I and Phase II Restoration Monitoring Plan Twelvemile Creek during road building and timber harvest in February 2013 Tongass National Forest, Craig Ranger District 1

2 Monitoring Plan Project Objectives The Twelvemile Creek watershed restoration project area is located on central Prince of Wales Island in Southeast Alaska (USFS, 2011). This project was developed to reflect the purpose and needs outlined in prior documents that assessed the condition of the watershed and its related natural resources. These include: a Twelvemile Arm Landscape Assessment, completed in 2007 (USFS, 2007a), a Watershed Restoration Plan for Twelvemile Creek, created in 2007 (USFS, 2007b), and two Environmental Assessments that were prepared to propose both Phases of this restoration project (USFS, 2011 and USFS, 2012). To support those documents, in 2007 the condition of the habitat in tributary and mainstem sections of Twelvemile creek was surveyed using Region 10 protocols, and the results were compared to accepted values for the Region for similar channel types (Appendix B). Some key observations identified during that analysis included the identification of simplified instream morphology, the absence of key large woody debris and resulting low numbers of pools, and an anticipated decline in condition due to the deterioration of residual key pieces of legacy wood (USFS, 2007b and Appendix B). With those observations in mind, Phase I of the instream restoration project was developed for implementation in Fiscal Year 2012 (USFS, 2011). Phase II of the project was developed for implementation in Fiscal Year 2013 (USFS, 2012). The objectives for both phases of the instream project area include: Increase or maintain the Number of Pools per Meter to meet the Regional Habitat Variable Objectives for the flood plain process group (See Table 2). Increase or maintain the Total and Key Large Woody Debris densities to meet the Regional Habitat Variable Objectives for the flood plain process group (See Table 2). Build stable, functional, wood structures that meet documented objectives. Decrease the Width to Depth ratio at the reach scale. Protect eroding banks from mass failure in order to preserve existing early seral riparian vegetation. Increase or maintain the abundance and health of the adult and juvenile native fish populations. Monitoring Site Location Phase I The Phase I instream project area includes 17 treatment sites along approximately one mile of the mainstem of Twelvemile Creek. This section of the creek runs between the pulled crossings of the road on the downstream end and the road on the upstream end. A 700 meter segment of the total instream project area will be regularly monitored for changes in habitat characteristics (See Table 4). This monitoring reach will cover 8 treatment sites that have various objectives. The stream segments surveyed in the 2007 WRP analysis and in earlier Channel Condition Assessments did not include this exact project area, so baseline habitat condition data will only be gathered immediately prior to implementation. Additional monitoring will occur just after implementation and at intervals noted in the monitoring schedule in Table 4. 2

3 Figure 1: Phase I Monitoring Reach Phase II This phase will construct log structures at 8 treatment sites along a 0.5mile stretch of stream immediately downstream of the lower extent of Phase I. This section begins just upstream of the pulled road crossing and the temporary road _5.44R. A 500 meter section of the Phase II project area will be monitored using the following methods (Monitoring Methods below), and on a schedule indicated in Table 4. This monitoring reach will overlap with sections that were surveyed in 1997 and in 2007 so that data comparisons can be made over time. Figure 2: Phase II Monitoring Reach 3

4 Monitoring Methods Habitat Variable Assessment: In order to monitor the changes in pool habitat and woody debris characteristics, we will use habitat survey protocols from the US Forest Service Region 10 Aquatic Management Handbook to compare the pre and post treatment conditions to the Region 10 Habitat Management Variables for the Floodplain process group (USDA, 2001). The comparison is based on the percentiles and associated condition value for each variable (Tucker and Caouette, 2008). Tier II Habitat Survey- The key variables obtained from the Tier II survey will be the number of pools per kilometer of stream, pool length per meter of stream, and the pool spacing. Tier IV Large Wood Counts- The attributes of interest in regards to large woody debris will be the total number of pieces per meter of stream and the number of key sized pieces per meter of stream. The Tier IV survey also places each piece of LWD into a size category, which produces a more precise assessment of the large woody debris characteristics through the comparison of the number of pieces in each size class over time. Table 1. Data Collection Method and Equation Used to Calculate the Habitat Response Variables. Habitat response variable Equation Data Collection Methods Pools/Km (POOLS/KM) Total Number of Pools / Meters Surveyed * 1000 Total count of pools. Total length of stream surveyed. Pool Length/Meter (PLNGTH/M) Total Pool Length / Total Length of Stream Surveyed Sum of all pool lengths. Total length of stream surveyed. Pool Spacing (POOL SPACE) Residual Pool Depth/ Channel Bed width (RPD/CBW) Length of Stream Surveyed / Channel Bed Width / Total Number of Pools Average of all pool residual depth / average channel bed width Total length of stream surveyed. Average channel bed width (width of active channel bed from bottom of bank to bottom of bank) averaged for the reach. Total number of pools. Residual Pool depth = maximum pool depth pool tail depth Average channel bed width Total Large Wood pieces / Meter (TLWD/M) Total Pieces / Meters Surveyed Total count of large wood pieces >1 m long and 0.1m in diameter. Total length of stream surveyed. Total Key Pieces Large Wood/Meter (TKWD/M) Total Key Pieces / Meters Surveyed Total count of key large wood pieces. (Key piece size based on average channel bed width of stream surveyed.) Total length of stream surveyed. 4

5 Table 2. Values of Habitat Management Objectives for Flood Plain Process Group Channel Types FPL and FPM. Pool Pools/Km Plength/M RPD/CBW TLWD/M TKWD/M Habitat Management Objectives Space* FPM FPL FPM FPL FPM FPL FPM FPL FPM FPL FPM FPL 25th percentile (fair condition) th-50 50th percentile (good condition) th 75th percentile (excellent condition) *Note that Pool Space follows a different trend that the other values, where a lower value is better condition. Cross Section and Sediment Size Comparisons In the Phase I Monitoring Reach, five Cross Sections will be monumented in the near vicinity of Treatment Site 5 to detect changes in channel morphology in direct relation to the log structures placed there. Within the Phase II Monitoring Reach, existing cross sections that were established during a 1997 Channel Condition Assessment will be resurveyed. Structure Objectives To determine whether or not the log structures are stable and meeting their design objectives, we will track their status using the forms and protocol in Appendix A. Initially, these forms will be used to establish the objectives for each structure and will later be used to monitor the success or failure of each structure. While subjective, this type of information will be critical in determining whether or not our anticipated objectives are being fulfilled by the implemented designs. Photo Points In conjunction with the Structure Objective data, pictures taken of the treatment sites and their associated stream reaches will be compared prior to and after restoration implementation throughout the entire project area. These photos will be assessed for large scale changes in the log structures as well as the channel features above and below the structures. Photo points will be monumented and documented following the Standard Operating Procedure outlined later in this document. Two photo points will be established in an attempt to reoccupy the following locations in these photographs taken in

6 Figure 3: 1960 Photo of Twelvemile Mainstem from bend above gage house. Figure 4: 1960 Photo of Twelvemile Mainstem from bend above gage house. Low Altitude Aerial Photography Low altitude aerial photos of the Twelvemile Creek mainstem were taken in the spring of 2010, prior to any restoration treatment. They will be taken again in the Spring of 2013 and These images will be mosaicked together and assessed for large scale changes in the placement of log structures and stream channel response/migration. Adult Salmonid Escapement Counts Adult steelhead and coho escapement counts have been conducted in Twelvemile Creek for several years. These surveys will continue according to the ability of district personnel and the cooperation of stream flows during the peak timing. The location of steelhead redds during peak counts have also been documented during some surveys. This process should be continued, especially within the project area. 6

7 Figure 5. Steelhead Escapement Count Results by Year Figure 6: Coho Escapement Count Results by Year Juvenile Outmigrant Monitoring A smolt trap was operated in Twelvemile mainstem in 2012 and will continue for a minimum of two more years to monitor and enumerate smolt migrating to the ocean. This aspect of monitoring will be included in a separate report. 7

8 Summary Table of Monitoring Methods Table 3: Restoration Objectives and Corresponding Monitoring Method Intensive Reach Restoration Treatment Objectives Increase or maintain the number of pools per kilometer at or above 25. Increase or maintain the Key Large Woody Debris densities to above 0.08 pieces per meter. Increase or maintain Total Large Woody Debris densities to above 0.46 pieces per meter, with an emphasis on increasing the number of pieces that are 0.3 meters in diameter and longer than 15 meters in length. Decrease width-depth ratio. Build and maintain stable, functional wood structures that achieve the objectives of each site. Reduce stream bank erosion and resulting lateral channel migration to protect regenerating riparian forest vegetation. Increase or maintain the abundance and health of the native fish populations within the watershed. Monitoring Method Tier II Habitat Survey Tier IV Wood Survey Tier IV Wood Survey Cross Sections Photo Points, Structure Objective Surveys, and Low Altitude Aerial Photography Low Altitude Aerial Photography Adult Escapement Counts, Juvenile Outmigrant Smolt Trapping Monitoring Schedule Table 4: Monitoring Schedule Twelvemile Mainstem Instream Restoration Monitoring Schedule Year Task Annually Phase I and II: Escapement Counts for Steelhead in April and Coho in October 2010 Phase I and II: Low Altitude Aerial Photos: April, prior to leafout Prior to Phase I Implementation Phase I :Tier II and Tier IV Habitat Survey in monitoring reach: April/May Photo point establishment : April/May Post Phase I Implementation Prior to Phase II Implementation Phase I: Log Structure Objectives for all treatment sites: August/Sept Tier II and Tier IV Habitat Survey in monitoring reach: Aug/September Photo point monitoring: August/September Phase II: Log Structure Objectives for all treatment sites: Sept/October Photo point establishment: October Phase I and II: Low Altitude Aerial Photos: April, prior to leafout Phase I: Tier II and Tier IV Habitat Survey in monitoring reach: April/May Photo point monitoring: April/May Phase II: Tier II and Tier IV Habitat Survey in monitoring reach: April/May Cross Sections and Pebble Counts: April/May 8

9 2013- Post Phase II Implementation Phase II: Tier II and Tier IV Habitat Survey in monitoring reach: August Cross Sections and Pebble Counts: August Photo point monitoring: August and October Phase I and II: Log Structure Objectives for all treatment sites: April/May Cross Sections and Pebble Counts: April/May Photo point monitoring: April/May Low Altitude Aerial Photos: April, prior to leafout Phase I and II: Low Altitude Aerial Photos: April, prior to leafout Tier II and Tier IV Habitat Survey in monitoring reach: April/May Cross Sections and Pebble Counts: April/May Log Structure Objectives for all treatment sites: April/May Photo point monitoring: April/May Specific Standard Operating Procedures Tier II and Tier IV Habitat Surveys These surveys encompass a very valuable segment of the monitoring data for this project. The importance of conducting these surveys thoroughly, accurately, and consistently cannot be overstated. Prior to conducting these surveys, refamiliarize all survey participants with the protocol in the 2001 Region 10 Aquatic Habitat Management Handbook, just to be absolutely certain that the surveys are conducted correctly. At least one of the crew members on the survey crew should have attended the Fish and Aquatic Stream Habitat Survey Training. The protocol should be followed for the Tier II and Tier IV surveys, however, only certain elements of each survey are necessary. The reason for using a combination of the Tier II and Tier IV surveys is mainly to get a more detailed wood count without having to perform an extensively detailed habitat survey. Only the habitat/stream survey part of the Tier II needs to be conducted, not the wood, cross section or the pebble count. The Tier IV protocol should be referred to just for the wood counts, and some modifications were made. Follow the clarifications below: Tier II Surveys Surveys should start parallel to the flagging at the upstream end of the monitoring reach and follow the centerline of the active channel through the last habitat unit (pool, riffle), sometimes going beyond the upper extent of the reach if necessary. Install stakes on the banks at the 0 meter mark and every 100 meters after, to ensure that future surveys can note the migration or stability of major habitat units. Stakes should be visible and GPS coordinates for the stakes should be taken. Detailed notes and hip chain distances should be recorded at features like treatment sites, start and end points, the upper or lower extent of the survey, tributary confluences, road crossings, cross sections, entry and exit points of side channels, and any other obvious features. All side channels should be fully surveyed. Tier IV Surveys In reference to counting clusters; tally the number of clusters in each habitat unit, but also tally each piece of wood within cluster individually, according to the appropriate size class. Additionally, 9

10 count all qualifying pieces of wood that are touching at least one other piece of wood in the cluster, regardless of the zone in which they are located. For example, if you are counting the individual pieces in a cluster that begins within bankfull width or height, include all touching pieces even if some of the other pieces are located in the floodplain (not within bankfull width or height). Indicate whether or not a key-sized or non key-sized rootwad is attached to each piece of wood. In order to reduce single observer bias, perform the Tier IV with at least 2-3 people, and measure the length and diameter of all pieces until all members of the group are calibrated and confident. Data Entry After collecting field data on the appropriate datasheet, all data (including survey notes) should be entered into an excel workbook, and double checked for accuracy. Using a copy of the digital version of the datasheet is the most effective method for data entry. Store all data on the O drive under O:\NFS\Tongass\Program\2500WatershedAirMgmt\ 2510WatershedPlanning\POW\Watersheds\Twelvemile Watershed\Twelvemile_Surveys_Data Photo Points Photopoints should be established at each engineered logjam site in conjunction with the Structure Objective data collection and should be monitored concurrently. Photopoint locations will be monumented and tagged, and the locations will be mapped. The photos and objectives will be incorporated into a document and stored on the O drive under O:\NFS\Tongass\Program\2500WatershedAirMgmt\ 2510WatershedPlanning\POW\Watersheds\Twelvemile Watershed\ Twelvemile_PhaseI_Implementation\Photos (or Phase II_Implementation). Aerial Photos In the spring of 2010 low altitude aerial photos were taken from the property boundary to the estuary, encompassing the entire FY 2012 and 13 project areas. These photos will be digitally joined together and compared to subsequent photo sets. Schedule these flights well in advance and request that they be flown prior to the leaf out of the alders along the riparian areas (March or early April). 10

11 References Tucker, E. and J. Caouette. June Updated Statistics for Aquatic Habitat Response Variables: Design, Analysis and Future Work. Tongass National Forest White Paper, Draft. June USFS US Forest Service Region 10 Aquatic Habitat Management Handbook. USDA Forest Service, Alaska Region. FSH November USFS 2007a. Twelvemile Arm Landscape Assessment. USDA Forest Service, Tongass National Forest, Craig Ranger District. March, USFS 2007b. Twelvemile Creek Watershed Restoration Plan. USDA Forest Service, Tongass National Forest, Craig Ranger District USFS Twelvemile Creek Restoration Environmental Assessment. USDA Forest Service, Tongass National Forest, Craig Ranger District. R10-MB-738. December USFS Twelvemile Creek Restoration -Phase II Environmental Assessment. USDA Forest Serivce, Tongass National Forest, Craig Ranger District. R10-MB-755a. December

12 Appendix A: Structure Monitoring Field Forms 12

13 Appendix B: Twelvemile Creek Habitat Analysis (draft 10/26/2007 d.kelliher) Habitat Attributes The 2007 habitat surveys produced values for three statistically significant habitat attributes. The three attributes are used to evaluate disturbance and proper functioning condition in alluvial channels. The three habitat attributes are: Width to Depth ratios (WD), Total Key Woody Debris per Meter (TKWD/m) and 13

14 Total Pools per Kilometer (Pools/km). Two habitat attributes that address pool quality are also included in this assessment. Mean Residual Pool Depth/ Average Bankfull Depth (Pool Size) Mean Residual Pool Depth/ Average Channel Bed Width (RPD/CBW) The habitat attributes and interpretation criteria were first introduced as indicators of habitat condition in 1995 for the Tongass Anadromous Fish Habitat Assessment. The interpretation criteria for each habitat attribute are listed below. The percentile values are specific to channel types and process groups. WD: Fair Habitat condition for values at or below the 25 percentile Good Habitat condition for values between the 25 and 50 percentile Fair Habitat condition for values between the 50 and 75 percentile Poor Habitat condition for values at or greater than the 75 percentile TKWD/m and Pools/km: Excellent Habitat condition for values at or exceeding the 75 percentile. Good Habitat condition for values between the 50 and 75 percentile. Fair Habitat condition for values between the 50 and 25 percentile. Poor Habitat condition for values at or below the 25 percentile. Pool Size and RPD/CBW: Excellent Habitat condition for values at or exceeding the 75 percentile. Good Habitat condition for values between the 50 and 75 percentile. Fair Habitat condition for values between the 50 and 25 percentile. Poor Habitat condition for values at or below the 25 percentile. An increase in WD ratio infers aggradation of material from natural processes or land management practices. High WD ratios (at or above the 75 percentile) represent poor habitat conditions. Fair Habitat ratings are given to the 25 percentile and below and also to the range between the 50 and 75 percentiles. The low WD ratios may mean entrenchment has occurred as a result of downcutting with above normal bank erosion. Local knowledge of the assessed stream reach is needed to verify if this condition applies. As TKWD/M values increase, so does structural complexity which usually correlates to higher pool frequency (Pools/km). The higher the values for these two attributes the better the fish habitat quantity and quality. Pool Size and RPD/CBW address pool quality as a measure of residual pool depth relative to bankfull depth and channel bed width respectively. The premise is that pool habitat quality increases as the pool depth increases relative to channel geometry. The percentile values for RPD/CBW in FP5 reaches are ambiguous due to the low number of samples so it not used in the main stem habitat assessment. Twelve Mile Creek Main Stem Fish Habitat Assessment In August 2007 six stream reaches were surveyed using the R10 Tier 2 protocol. The sample reaches consist of two main stem FP5 reaches, one main stem FP4 reach and three tributary MM channels. One main stem FP5 was a CCA reach. It was first surveyed in 1997, therefore the data represents a span of 10 years for this reach. For the assessment of existing condition only the 2007 data for the CCA reach was used. A comparison of the 1997 and 2007 CCA site data is included for a change over time perspective. 14

15 The habitat attribute percentile values are specific to each channel type and process group. The percentiles for the FP5 and FP4 were used for the habitat assessment of the main stem reaches. However the number of FP5 sample reaches in the corporate data set from which the percentiles are derived is very small, less than ten. The habitat attributes were calculated individually then summarized for an overall rating for the two FP5 reaches. Table 1 lists the results. Table 1. Twelvemile FP habitat condition. FP Ratings Overall WD TKWD/m Pools/km Pool Size Excellent 8% 0% 0% 33% Good 25% 0% 0% 33% 67% fair 33% 67% 0% 67% 0% Poor 33% 33% 100% 0% 0% Channel Geometry The WD ratio for the lower FP5 reach was at the 25 percentile and in the range for the middle FP5 reach (CCA site). The upper watershed FP4 was above the 75 percentile for FP4 segments. These results indicate a tenuous state of equilibrium for sediment load and channel capacity to transport material. Therefore a rating of functional but at risk is warranted. The position of the FP4 channel in the stream network may account for the high WD ratio. Above normal deposition may occur in low gradient segments directly downstream of transport segments such as HC or MM channels. In comparing 1997 and 2007 WD data for 3 cross-sections in the CCA-FP5 reach some channel deepening has occurred. The channel Width to Depth ratio has decreased: mean bankfull depth has increased but channel width has changed to a lesser degree. A comparison of substrate sizes does not show any dramatic shift to larger particles. One cross-section is located immediately downstream of a former bridge site, one is just upstream and the third lies on a channel bend. The channel constriction from the old bridge site may account for the increase in depth at the lower cross-section as higher flow velocities during bankfull or higher flow event may occur in this segment. Table 3 shows the 1997/2007 data comparison for habitat variables.. Table 3.Comparison of Stream Geometry at the CCA site. W/D ratios XS riffle XS riffle XS pool* Mean depth XS XS

16 XS average Bankfull width XS XS XS Particle Size (d50) XS coarse gravel XS coarse gravel XS n/a med gravel * not used for average WD calculations Key Wood The key wood data indicate a very low amount of key wood in the FP channels. All the main stem reaches have TKWD/m values below the 25 percentile. These data indicate an extensive lack of large wood structure and habitat diversity in the main stem. Future wood recruitment is also compromised in some sections where young growth conifer or alder stands are the predominant riparian vegetation. Pool Habitat The pool frequency data resulted in a Fair rating for the FP5 segment and Good rating for the FP4 segment. Though key wood amounts are low, pool frequency is holding up in the main stem. In the FP5 reaches Pool Size indicates good pool habitat quality. Therefore, even though pool quantity is fair pool quality is good. The Pools/km values are just above the 25 percentile which represents the hydraulic threshold for pool frequency in FP channels. In comparison to the composite percentiles for the FP process group, the main stem FP5 pool frequency is very low. In the FP4 segment pool quantity and quality are good. Pools are smaller but more frequent in the FP4 channel. If sediment loads and routing remain in balance the pool habitat should sustain the current quantity and quality levels. Conclusions for the Main Stem Existing Condition The habitat data represent a marginally functional FP5 main stem. The main stem is lacking in key wood which is reflected in low pool frequency. Given the current lack of key wood structure pool frequency is at the base line level. At best, the main stem will retain the current pool quantity and quality in the future if no perturbations occur in high flow or sediment levels. The upper main stem FP4 is in better functional condition with good pool frequency and quality. The WD ratio is very high for the FP4 as it exceeds the 75 percentile. This high sediment load is likely the result of the segment location being directly downstream of high gradient segments and therefore expected and normal for this segment. Overall sediment load and routing capacity are in balance. Though the CCA reach has deepened, WD ratios are still within normal ranges. The WD ratio for the lower FP5 reach rates as Fair but in the low range. However, observed point and medial gravel deposits appear normal for a large alluvial channel. See photos 1 and vs CCA site There is no key wood data in the 1997 CCA survey. The Pools/km values have remained constant at a value of 11 for both samples. Pool Size has also remained constant. Mean bankfull depth has increased 16

17 from 0.75m in 1997 to 0.98 in 2007 but so has mean residual pool depth, from 0.74 to From these data, there has been no change in pool frequency or quality over the ten year span between samples. Overall conclusion for the main stem is that present habitat conditions are functional though of limited diversity. The long term outlook is for gradual deterioration of the pool habitat as residual key wood decays and is not replaced and more rapid decline if the sediment balance is disrupted. Twelve Mile MM tributary Assessment As with the FP data the MM habitat variables were summarized for an overall rating. Table 2. Twelvemile Tributary habitat condition. MM ratings Overall WD TKWD/m Pools/km Pool Size RPD/CBW Excellent 20% 67% 33% 0% 0% Good 0% 0% 0% 0% 0% 0% Fair 20% 33% 33% 0% 33% 0% Poor 60% 67% 0% 67% 67% 100% Channel Geometry The WD ratio for two sites registers in the poor range and one site in the fair range. The two MM reaches in the main Twelvemile watershed exhibit higher than normal sediment storage. Proximity to a recent landslide may account for the high sediment load in one reach, the catchment MM1. The other MM1 is in a much larger sub-watershed and lies directly downstream from a high gradient contained sediment transport channel (HC3). Sediment levels may be attributed to transport downstream from the HC3 channel. The third site, a wider MM2 channel, is in the Cave Creek sub-watershed. This channel also has a WD at the 75 percentile threshold. This reach is immediately downstream of low gradient contained channel. See Photo 6 for a view of the smaller MM1 and Photo 7 for the larger MM1. Key Wood TKWD/m values for this attribute indicate a healthy quantity of key wood present in the MM reaches. Future key wood recruitment is compromised as the riparian area is now in young growth riparian forest. Wood is the primary pool forming agent in the Twelvemile MM channels. Key wood structures produce durable pools that will withstand high flow events. Small diameter alder accumulations also create pools in MM channels as is evident in Photos 8 and 9. However pools and sediment deposits dependent on small wood may be more susceptible to destruction by high flow events. Small wood structures are very unstable and easily broken up by flood flows. Rapid mobilization of sediment deposits and loss of the pool habitat are a concern with these unstable wood structures. Pool Habitat. Pool frequency is greatest in the catchment MM1 (Tributary A) and low in the sub-watershed MM1 (Tributary B) and the MM2 Cave Creek channel. In all reaches pool quality is poor, due to shallow depths relative to channel depths and widths. The Twlevemile tributary MM1 channels present the most concern, due to sediment deposits and shallow pool habitat. Though currently ample key wood exists the pool habitat quality is marginally functional. The available habitat is threatened by sediment deposits retained by tenuous wood structures, and no future key wood recruitment from a young growth riparian area. 17

18 In the Cave Creek MM2 four of the five attributes are in the poor range, only key wood registers a fair rating. Pool frequency and quality are poor. A marginally functioning habitat condition currently exists but this is likely the natural condition for this transitional reach. The sub-watershed above is steep, dominated by High and Moderate Gradient channels. Stream flow rises rapidly in response to precipitation events. The MM2 reach lies directly below a short narrow Low Gradient Contained channel that is heavily loaded with woody debris. This constricted channel accelerates stream flow velocities and the MM 2 channel must then dissipate this energy. Given this energy dissipating function in the Cave Creek in the MM2 reach marginal habitat conditions are expected. See Photo 10 and 11 for a view of the MM2 reach. In conclusion, the Twelevemile Creek MM channels contain functional but low quality habitat due to location, watershed processes and a riparian area dominated by young second growth vegetation. In addition the small wood accumulations retaining sediment pose a threat to the shallow pool habitat in the tributary MM1 reaches. 18

19 Table 4. FP ratings. Habitat Attribute Percentile FP3 FP4 FP5* Process Group FP CCA FP5 Lower FP5 Upper FP4 Rating Fair _low WD Good Fair_high Poor TKWD/m Poor Fair Good Excellent Poor Pools/km Fair Good Excellent * low sample size (n<10) Poor Pool Size Fair (rpd/avbfd) Good Excellent RPD/CBW Poor Fair Good Excellent 19

20 Table 5.MM ratings. Process Cave Habitat Group Trib A Trib B Ck Attribute Percentile MM1 MM MM1 MM1 MM2 Rating Fair _low WD Good Fair_high Poor TKWD/m Poor Fair Good Excellent Pools/km Pool Size (rpd/avbfd) RPD/CBW Poor Fair Good Excellent Poor Fair Good Excellent Poor Fair Good Excellent 20