Bibliography Background About KRIS
KRIS Ten Mile Info Links
Ten Mile River Flow and Regional Rainfall Data
Flow data in KRIS Ten Mile comes from U.S. Geologic Survey (USGS) records for the Clark Fork or Middle Fork Ten Mile River provided by Graham Matthews as part of data acquired for the Sediment Source Analysis and Preliminary Sediment Budget for the Ten Mile River, Mendocino County, CA (Matthews, 2000). Records of average daily flow are in cubic feet per second. Water years begin on October 1 of the prior calendar year. For example, the 1998 water year started on October 1, 1997. Rainfall is available in KRIS Ten Mile for Ft Bragg and Willits, which are the closest rain gauges to the watershed. Data origin is the National Weather Service CDEC database and James Goodridge, former state climatologist and now consultant to the California Department of Water Resources. Rainfall data was assimilated by Matthews and provided for use in KRIS. See the Stream Flow KRIS Ten Mile Background page for more information.
Historical Photos Courtesy of the Held-Poage Research Library and Mendocino Historical Society
Historical photos in the KRIS Ten Mile project were scanned from the collection at the Held-Poage Historic Home and Research Library in Ukiah. Rights to use the photos in KRIS were granted by the Mendocino Historical Society. This treasure trove of historical images allows us to see channel conditions and land and gain valuable insight into an era before scientific data was collected. The images are for viewing in this project only and further use of these photos requires the express and written permission of the Mendocino Historical Society. Photo negatives were collected by Robert Lee who developed the prints on display at Held-Poage. Photos date back as early as the 1850s. Notes are from Mr. Lee and numbers in his reference system are entered in the captions for the photos.
Photos from the Margaret Perry Family
Mrs. Margaret Perry was contacted by Vivian Helliwell of the IFR KRIS project and allowed her families historical photographs of the lower Ten Mile River to be scanned. These images cover the effects of the 1964 Flood and include aerials from a Life magazine photographer who was a friend of the family's and in the area just after the flood. All rights of these photographs are retained by the Perry family and any further use should be with their permission.
Friends of the Ten Mile River provided photographs for the KRIS Ten Mile project. Images include interesting shots of the river from a kayak, taken by Erica Felder, and aerial photos by Rixanne Wehren, which help portray watershed conditions. Juidth Vitaver was very helpful in coordinating acquisition of information from the Friends of Ten Mile River.
Aerial and Ground Photos by Nicholas Wilson
Nicholas Wilson contributed aerial and ground photos of timber harvests and watershed conditions from the late 1980's and early 1990s for the KRIS Ten Mile project. Nick is a photographer who lives in Little River, California. All of his photos are copyrighted and can only be used with his permission. Nicholas Wilson,707-937-0137, PO Box 943, Mendocino CA. Nick's original captions and notes on photo processing can be viewed as File Info inside Photoshop if photos from KRIS are opened in that program.
Aerial and Ground Photos Contributed by Nicholas Wilson
Nicholas Wilson contributed aerial and ground photos of timber harvests and watershed conditions from the late 1980's and early 1990s for the KRIS Ten Mile project. Nick is a photographer who lives in Little River, California. All of his photos are copyrighted and can only be used with his permission. Nicholas Wilson,707-937-0137, PO Box 943, Mendocino CA. Nick's original captions and notes on photo processing can be viewed as File Info inside Photoshop if photos from KRIS are opened in that program.
Road Densities in KRIS Ten Mile
Roads are a major source of sediment to streams. Surface erosion from roads can produce chronic sources of fine sediment which can diminish salmon and steelhead spawning success. Failure of roads during major storm events can lead to large landslides which can overwhelm streams with sediment, thus filling pools and diminishing habitat diversity. Road densities in KRIS Ten are taken from Matthews (2000) and were calculated from aerial photographs for different periods except that information from the California Department of Forestry was used since 1988. Road densities since 1996 are projected in some cases from Timber Harvest Permits (THPs) filed with CDF and may not yet have been constructed. KRIS shows thresholds for roads of 3 miles per square miles based on National Marine Fisheries Service guidelines (NMFS, 1996). See Roads page in KRIS Ten Mile Background pages for more information.
California Department of Fish and Game Electrofishing Survey Data
The California Department of Fish and Game (CDFG) has contributed two sets of electrofishing data from Mendocino coastal area. Weldon Jones and other CDFG staff began sampling various stream locations throughout Mendocino watersheds in 1983. Since 1996, the effort has continued under the leadership of Scott Harris and generated several long term datasets, including those for Pudding Creek, Dehaven Creek, and Wages Creek. Electrofishing samples are generally taken in August through October when juvenile migration has abated and the resident fish population is most easily characterized. The resulting database (CDFG biosample database) was shared with the KRIS project and used to demonstrate fish community structure for locations within the project area. Specific techniques used by CDFG staff, such as the use of blocking nets, and single versus multiple pass varied. As a result, some of these data should not be used to compare fish abundance or fish densities over time or between reaches. Information on sampling technique is currently limited to fields in the Source Table. Presentation of the data in KRIS is intended to characterize the fish community structure for a variety of sites and years. Chart and chart table captions describe some of the sampling details that effect how quantifiably each record may describe actual fish density or population trends. Although the biosample database lists virtually all species of aquatic vertebrates that may occur, sample data indicates that amphibians and possibly some non game fishes were not recorded until the most recent years.
The other set of electrofishing data from CDFG was collected as biological inventory during stream habitat inventories. Habitat typing surveys conducted by CDFG between 1994-1999 involve crews staffed by California Conservation Corp. and Americorp technicians with minimal experience. Surveys follow methods described in the California Salmonid Restoration Manual (CDFG, 1998), and include electrofishing of representative habitats, but no use block nets, or any protocol to allow quantitative calculations. Sampling effort is minimal. Non detection of a species, such as coho salmon, cannot be taken as total absence. Furthermore, these inventories are highly variable with respect to documenting non game fishes and amphibians. Because of such limitations, these data are not highlighted in KRIS, but can be found in the stream inventory reports contained within the KRIS Bibliography. Some examples of these data are used, however, as a simple indicator of fish species presence and fish community structure. The ratio of coho to steelhead, and the change in this ratio over time, reveal information about habitat change and suitability.
For more in-depth information see also Fish Population and Fish Population Information in KRIS Ten Mile.
The removal of wood from streams or "stream cleaning" began in coastal rivers of Mendocino County in the late 1950s and was a misguided attempt to improve fish habitat that had been degraded by logging activities. The idea was to re-establish fish passage around large wood jams and allow for faster flushing of sediment. Large wood removal in the Ten Mile River Basin is documented by memos from 1982-1984. These documents are available in the KRIS Bibliography and were used by Hawthorne Timber Company staff to produce a map and some summary tables documenting the known extent of wood removal activities in the Ten Mile River Basin. These tables identify reach lengths, locations, number of log jams, and jams removed for streams of the South Fork, Middle (Clark) Fork, and Mainstem Ten Mile River.
To learn more about removal of wood from streams see the Background page on Stream Clearance in the Ten Mile.
Fisheries Data from Hawthorne Timber Company
Twenty four sites throughout the Ten Mile River watershed have been subject to multiple pass electrofishing each year since 1993. The original sites were established by Georgia Pacific staff for the purpose of providing uniform coverage of the watershed and an equal distribution of sample locations on the mainstem and tributaries. The sites are actually 30 to 50 meter reaches, located near temperature monitoring stations, and including a combination of pool and riffle habitat. Reach limits are defined by change in habitat type, and 4.5 mm mesh blocking nets where used when sampling. Sampling occurred in September or early October when flows are low and fish have become less mobile. Data collected during the surveys include habitat area, number of vertebrates captured by species, and species biomass per site. These data provide useful trend monitoring for the 24 reaches, and an indication of where species are present among a dispersed sample of locations. Data from these surveys can not be used in any statistically valid estimation of population levels for an entire stream because sampling locations were not chosen randomly. Even the validity of these sites as "representative reaches" may be compromised by the fact that they were established before stream surveys in 1995. Nevertheless, population size estimates for coho salmon were calculated by Hawthorne Timber Company staff by applying the density of coho, where captured, to estimates of habitat area for particular sub basins. These estimates are presented in KRIS Ten Mile for their possible value in interpreting, at coarse resolution, the abundance of coho in Ten Mile sub basins. For more information see Ten Mile River Watershed monitoring reports in KRIS Bibliography, or click here: Ambrose et al. 1996, Ambrose and Hines 1997, Ambrose and Hines 1998.
Data from HTC electrofishing is presented in KRIS Ten Mile for each site as either the total catch by species for a given, or time series (1993-2000) for groups of amphibian or fish species. The total catch presentation utilizes a common KRIS chart style which is used for interpreting species composition or community structure. Of the 192 such charts possible from the data set, only two example years per site have been constructed -- the most recent year (usually 2000), and 1994, when available. The first year of record, 1993, is suspect of errors from inexperienced technicians. Time series data for each site is presented as biomass, density, and total catch of key species. Time series data is presented for amphibian and fish species, separately, although non represented species can be added to a graph by simply selecting an additional chart table column in the lowest open drop down box to the right of the chart.
| TEN1 | Mill Creek | CO | Coho Salmon |
| NFT1 | North Fork at Patsy Creek | SH | Steelhead Trout |
| NFT2 | Bald Hill Creek | SB | 3-Spined Stickleback |
| NFT4 | North Fork at Camp 3 | CS | Coastrange Sculpin |
| NFT5 | North Fork at Camp 5 | PS | Prickly Sculpin |
| NFT6 | Lower Little North Fork | SC | Sculpin Spp |
| NFT7 | Buckhorn Creek | LP | Lamprey Spp. |
| NFT8 | Upper Little North Fork | CR | Ca. Roach |
| NFT9 | North Fork at Gulch Nine | SQ | Sacramento Squawfish |
| CFT1 | Middle Fork at Reynold's Gulch | SU | Sacramento Sucker |
| CFT3 | Lower Bear Haven Creek | PG | Pacific Giant Salamander |
| CFT5 | Booth Gulch | CN | California Newt |
| CFT6 | Little Bear Haven Creek | RB | Red-bellied Newt |
| CFT7 | Upper Bear Haven Creek | RN | Rough-Skinned Newt |
| CFT8 | Middle Fork at Ford Gulch | BF | Bullfrog |
| SFT1 | Lower Smith Creek | PF | Pacific Tree Frog |
| SFT2 | Lower Campbell Creek | RF | Red-legged Frog |
| SFT3 | South Fork at Brewer's Gulch | TF | Tailed Frog |
| SFT4 | Churchman Creek | YF | Yellow-legged Frog |
| SFT5 | South Fork at Buck Mathews | CF | Crayfish |
| SFT6 | South Fork at Camp 28 | ||
| SFT7 | Lower Redwood Creek | ||
| SFT8 | Upper Redwood Creek | ||
| SFT9 | Upper South Fork Ten Mile | ||
David Hines, then the Fish Biologist for Hawthorne Campbell, led a 2000 survey of all potential coho rearing habitat in tributaries and branches of the Ten Mile River. The survey involved the snorkeling of every pool and pocket water habitat in over 35 miles of stream, and established, with a high level of certainty, where coho were present, and where coho absent in that year. The survey also generated a basin-wide estimate of 1731 juvenile coho for the entire Ten Mile River basin.
To see summary data on the presence of coho salmon, as well as sediment and temperature parameters, for monitoring sites in the Ten Mile River basin, click here: Table of monitoring site locations and summary parameters.
Coho Presence and Absence Surveys
Direct observation and single pass electrofishing were used by Adams et al. (1999) to determine presence and absence of coho salmon relative to historic surveys throughout the Central California region (ESU), including Mendocino County. These data summarize coho absence rate by county. Because the varying returns of different year classes of coho, three consecutive years of survey are needed for definitive presence/absence information. In the period 1990-1991, Brown et al (1994) compiled all available data on the current presence of coho salmon relative to historic information. Data used to document the presence or absence of coho in Mendocino Coastal streams included both snorkel and electrofishing surveys. Data from this compilation and analysis is available in the appendixes of Brown and Moyle, 1991.
For more in-depth information see also Status of Pacific Salmon in Mendocino Area Background page, Fish Population, and Fish Population Information in KRIS Ten Mile.
Stream Temperature Monitoring in the Ten Mile River Watershed
Stream temperature can be the single most critical feature of habitat for fish and other aquatic organisms, and is relatively easy to monitor. Georgia Pacific established 24 temperature monitoring sites in the Ten Mile River watershed in 1993, and those sites have since been maintained by Hawthorne Timber Company (HTC), although not every site is monitored in each year. For more in-depth information on water temperature and reference to key literature, see the Temperature Background page.
HTC provided 1993-1998 water temperature data to the KRIS Ten Mile project in the form of Excel files containing temperature data in the form of daily and weekly averages. HTC subsequently provided raw temperature data for sites monitored in 1999-2001. Floating weekly average temperature (FWA = the average of seven daily average values around a date) was calculated and charted for all sites. FWA is also plotted for groups of sites that show changes in water temperature moving along a stream course. Based on known thermal tolerances and field studies by Welsh et al. (2001), coho salmon are unlikely to persist where the maximum weekly average temperature (MWAT = maximum seasonal FWA) exceeds 16.8 degrees C. This value is used as a reference on all FWA charts.
Floating weekly maximum (FWM) has been suggested a better indicator of acute stress for salmonids because it is not diminished by night-time lows where diurnal shifts in temperature are high. FWM charts are provided for 2001 data. The reference value for maximum weekly maximum temperature (MWMT = maximum annual FWM) comes from Hines and Ambrose (in review) who found that coho salmon do not persist in the Ten Mile River or other regional streams where FWM exceeds 18.3 degrees C. Daily minimum, maximum, and average temperatures were charted for all sites monitored in 2001 (See topics "Temperature: MMA ..."). The MMA charts can be used to assess actual maximum temperature and diurnal variation and show as a reference the preferred temperature range of salmonids as supported by the literature. A table of monitoring site locations and summary parameters has been prepared showing how temperature monitoring sites in the Ten Mile River were also used for sediment and aquatic vertebrate monitoring.
Downstream Migrant Trapping Data
Downstream migrant traps can yield uniquely valuable information on the productivity and health of watersheds by measuring the number of juvenile fish leaving a stream and providing an opportunity to measure the size of those downstream migrants. Coho and steelhead juveniles must reach at least one year of age, and attain sufficient size, in order to survive the smolt and early ocean life stages. Large numbers of coho or steelhead yearlings (1+) indicate a potentially productive salmonid stream, while large numbers of young of the year fish (0+) can indicate habitat conditions too poor to support juvenile rearing. Maintaining traps and generating reliable estimates of total out migrant populations requires trap calibration, which was not attempted in the Ten Mile Basin. The Salmon Trollers Marketing Association placed and maintained three fyke net style downstream migrant traps in the South Fork Ten Mile River sub basin in 1995 and 1996. Data from the first year of trapping was not available, but the report for 1996 (Maahs, 1996) indicates that this was largely a pilot year for developing the trapping methods. Data from trapping in 1996 is presented in two forms, one to illustrate the various types of vertebrates captured at the trap sites, and the other to illustrate the timing and magnitude of out migration for the two age classes of coho and steelhead. In addition, the California Department of Fish and Game operated a fyke net in Wages Creek in 1999. Data from the Wages Creek trap is presented similarly.
Stream habitat surveys were conducted for 25 tributaries of the Ten Mile River by the Georgia Pacific Company in 1995-1996 and these data were provided by Hawthorne Timber Company. Survey methods followed protocols in the California Salmonid Restoration Manual (CDFG, 1998) and resulted in reports contained within the KRIS Bibliography. Of all the data available from these surveys, four habitat metrics (percent pools by length, maximum pool depth, embeddedness, and canopy) are considered most useful in assessing habitat suitability for salmonids. Charts of each of these habitat metrics present streams in order of basin area. Channel slope and type are also important stream characteristics that can influence habitat data and available information on these can be found in the habitat chart tables. To learn more about using fish habitat data, check the Habitat Typing Background pages.
Habitat typing is most simply the classification of unit lengths of stream as pool, flatwater, or riffle habitat. Both the quantity and quality of pool habitat is important for productive rearing of coho salmon and yearling or older steelhead. Percent pools by length reflects pool habitat quantity. Pool depth is an important component of pool habitat quality because juvenile coho and older steelhead prefer pools deeper than three feet and may require them for protection from predators. Maximum pool depth is an objective measurement taken at each pool. Embeddedness is a visual assessment of spawning habitat quality with respect to fine sediment levels. Although embeddedness is a subjective monitoring tool compared to McNeil samples, embeddedness is easily obtained and thus enables assessment of spawning conditions over extensive stream networks.
The percent canopy of trees over the stream is measured at each habitat unit and the relative proportions of canopy by deciduous and coniferous trees is noted. Canopy measurements are not only useful for assessing protection from direct solar radiation, but offer some indication of the structure of the riparian forest for maintaining microclimate and providing large wood to the stream channel. These habitat metrics have been presented in a basin wide context, as well as subbasin context, in order to facilitate analysis of habitat conditions at multiple scales.
Habitat data from the Ten Mile River Watershed was analyzed by the California Regional Water Quality Control Board in Assessment of Conditions in the Mendocino Hydrologic Unit (Mangelsdorf and Clyde, 2001). Summaries from the draft report were utilized in KRIS for easy sharing of habitat metrics explained above, as well as two additional habitat metrics: Percent scour pool habitat, and percent wood formed habitat. Mangelsdorf and Clyde (2001) found the availability of these habitats to be low in Ten Mile River tributaries compared to what is described by CDFG as for good salmonid streams, and also found that the percent area of these habitats correlates with where coho salmon have persisted in the late 1990's. Of the several types of pools classified by CDFG methods, scour pools are of highest quality for coho salmon due to their characteristics of depth and cover. Of the seven Ten Mile River basin streams comprised of more than 20% scour pool habitat, all but the Middle Fork (which is too warm for coho -- see Temperature Topics) have shown a recurring presence of coho salmon at electrofishing sites. Of the eighteen streams with less than 20% scour habitat, only Churchman Creek has shown recurring coho. A subset of scour pools are those that are formed and maintained by large wood. The five Ten Mile River tributaries with the highest percent wood-formed habitat (Bear Haven, Little North Fork, Smith, Campbell, and Churchman) are the only streams where coho persisted during the period 1994-2000. For more information on the function of large wood in streams see Large Wood Background pages.
Ten Mile River Sediment Source Analysis
Matthews (2000) calculated sediment yield from various sources and sub basins in the Ten Mile River watershed to assist the U.S. Environmental Protection Agency in the TMDL process. Sources of mass wasting were analyzed and changes in causative factors estimated over time. Aerial photos were used extensively to check road densities, the progression of timber harvest and linkage between land use and sediment yield. The heavy use of aerial photos sometimes made it necessary to make conservative estimates. For example, no history of timber harvest was available before 1942 (the earliest aerial photo series); consequently, all landslides in forested areas were categorized as "natural". Sediment transport estimates were calculated from regional data and recognized by the author as accurate only to an order of magnitude. Road densities since 1988 may be in part estimates from Timber Harvest Permits (THPs) on file with CDF, and to the extent that some of these plans are still pending approval, involve some overestimation. Matthews (2000) captured photographs which were then tiled into an ArcView coverage of the entire Ten Mile River basin in 1999. This can be seen in the KRIS Ten Mile Map project in ArcView or as images in Tours in the KRIS Ten Mile database.
The size distribution and permeability of spawning gravels is critical to the survival of incubating eggs and alevins (McNeil and Ahnell 1964). Suffocation can result from a reduction in the flow of water through the gravels due to high quantities of fine sediment less than 1 mm in size. After alevins hatch, they grow in the sub surface gravel environment until emergence which requires interstitial spaces through which the alevins can pass. Sediment 1 to 10 mm in size is considered deleterious to alevin emergence Kondolf (2000). Bulk gravel or McNeil samples provide a method to measure surface and sub-surface particles. For general methodology, see Measuring Sediment in Streams or Sediment Information in KRIS Ten Mile for a fuller description of data analysis.
The Hawthorne Timber Company provided McNeil bulk sample data for 23 Ten Mile River Watershed study reaches that have been monitored since 1993. Two representative riffles in each study reach were selected annually, but the same riffles were not necessarily sampled every year. Sediment was collected using a 6" McNeil core type grab sampler, and wet sieved on site. To review the Ten Mile River annual monitoring reports containing the study design and results, see 1995, 1996, 1997, 1999. For a list of sampling locations and summary results of fine sediment, temperature and aquatic vertebrate monitoring sites, see table.
Reference values for percent fine sediment less than 0.85 mm shown on charts are patterned after target values established by the U.S. Environmental Protection Agency and North Coast Regional Water Quality Control Board as part of the Clean Water Act Total Maximum Daily Load (TMDL) allocation. TMDL is aimed at abating water quality problems in impaired water bodies. The Ten Mile River TMDL for Sediment (EPA, 2000) set the target for wet sieved fine sediment <0.85 mm at 14% or less. The Big and Garcia TMDL reports recommend a maximum 30% for fines <6.4 mm, but no target for this size class was recommended in the Ten Mile River TMDL; This second category of fine sediment includes large sand and fine gravels which may intrude into the stream bed and inhibit the emergence of alevin (Chapman 1988). Kondolf (2000) reviewed 10 studies reporting <6.4 mm fine sediment percentages corresponding to 50% emergence of salmonids and reported 30% as a mean value. The sieve sizes used by Hawthorne Timber Company spanned the 6.4 mm class size, so a simple linear interpolation of the 6.4 mm size class was converted from the 4 and 8 mm size classes using methods suggested by Bunte and Apt (2001).
Knopp North Coast Regional Sediment Study
Excessive fine sediment fills pools and causes general instability of stream gravels and channel form. Loss of pool depth and channel complexity lowers the carrying capacity of streams for aquatic biota. The various indices for measuring such impairment of stream channels were tested by Knopp (1993) at 60 northwestern California sites. The proportion of a pool's residual volume that is filled by fine sediment is termed V-star (Hilton and Lisle, 1993) and V* values from Mendocino streams, including Churchman Creek and the South Fork Ten Mile River are presented in KRIS Ten Mile. Data from Knopp's testing of other indices, such as D50 and RASI are available in the KRIS Source Table, Knopp.dbf. The Ten Mile River TMDL for Sediment (EPA, 2000) set the target for fine sediment in pools as a V* value of 0.21. See the Sediment Background page to learn more.
Vegetation and Timber Types of Cal Water Watersheds
The vegetation and timber types used in the KRIS Ten Mile project was derived from Landsat multi-spectral images taken in 1994. The U.S. Forest Service Pacific Southwest Region Remote Sensing Lab, in cooperation with the California Department of Forestry, analyzed the Landsat images to formulate a California wide electronic map layer of vegetation as part of the Northwest Forest Plan (Warbington et al., 1998). See Vegetation Types Background page for more information.
Stand conditions are accurately represented at the one hectare scale by the USFS vegetation data. Data is quarried for tree size or community type in ArcView (KRIS Ten Mile Maps). This allows quantitative assessment of vegetation types for seral stage based on tree size for geographic areas such as Calwater planning watersheds in KRIS DB.
For use in KRIS, vegetation and timber types were simplified into ten classifications. Vegetation classifications are:
Very Large Trees = 40" in diameter or greater
Large Trees = 30-39.9" in diameter
Medium/Large Trees = 20-29.9" in diameter
Small/Medium Trees = 12-19.9" in diameter
Small Trees = 5-11.9" in diameter
Saplings = 1-4.9" in diameter
Non Forest = Non tree species such as shrubs, grasses or bare soil
This simpler classification provides an easy to understand index of watershed disturbance for use in coastal watersheds. Large components of early seral stage conditions (Saplings, Non Forest) are often associated with recent logging disturbance. The vegetation patterns in interior basins, such as the Eel River and Klamath River watersheds, are much more complicated than in coastal ecosystems and more difficult to use to analyze changes in vegetation brought about by watershed management activities. The KRIS vegetation classification scheme can also be used for a quick analysis of riparian conditions. Ninety meter (297 ft.) zones of riparian influence are assigned to the 1:24000 stream layer in ArcView and only the vegetation within this zone is displayed and analyzed.
Timber Harvest Data in KRIS Ten Mile
Timber harvest data in KRIS comes from two sources, Matthews (2000) and the California Department of Forestry (CDF). Matthews (2000) measured and mapped timber harvests from aerial photos dating back to 1942 but also included recent data from planned timber harvests from CDF. The CDF data is included in its entirety in the KRIS Ten Mile Map project and allows query on timber harvest type, acres, year, ownership and other parameters. See Timber Harvest Information in KRIS Ten Mile to learn more.
Aquatic Insect Samples from the Ten Mile River
Georgia Pacific Corp. (now Hawthorne Timber Company) collected aquatic macroinvertebrates at 27 stations in the Ten Mile River in 1995 (Hines and Ambrose, 1996). Aquatic insect communities make excellent indicators of the health of aquatic ecosystems and are widely used as an index of water quality (Plafkin et al., 1989; Barbour, 1999). Aquatic insect data for the Ten Mile River were collected as part of a basin wide water quality monitoring program which was supplied to the North Coast Regional Water Quality Control Board. Samples were collected using a kick net and preserved in alcohol. A representative sub-sample was then keyed but staff at GP was only able to identify organisms to Family. To meet California RAPID Bioassessment protocols (CDFG, 1999) samples should be keyed to species or the lowest possible taxonomic order. Also, some samples in the Ten Mile River were below the 300 organisms, which is the number usually required for a validity. Keying organisms to the Family level may mis-construe diversity because there may be several species within families represented in the samples. Because of the latter concern, KRIS Ten Mile did not use aquatic macroinvertebrate data from HTC.
Lower Ten Mile River Basin Description
The Lower Ten Mile basin is much smaller than other Ten Mile River sub-basin areas analyzed, with an area of only 8.83 square miles. The Lower Ten Mile has fairly flat terrain in the estuary and adjacent wetlands with pasture near the mouth extending upstream in the valley bottom. This watershed is adjacent to the coast and rainfall is the lowest in the Ten Mile River basin at about 40 inches annually. It rises sharply in the east at the headwaters of Mill Creek, where very steep slopes occur. For more information about map images see Map Background pages.
North Fork Ten Mile River Basin Description
The North Fork Ten Mile watershed elevations range from 40 feet (12. m) at the mouth to 2,200 feet (671 m) in the headwater areas and drains approximately 24,967 acres (10104 ha). The legal description at the confluence with the Ten Mile River is T20N R17W Sec25. Its location is 39° 33' 53 "N. latitude and 123° 42' 30"W. longitude on the USGS Dutchmans Knoll 7.5 minute quadrangle. Major tributaries include the Little North Fork Ten Mile, Cavanough Gulch, O’Connor Gulch, Bald Hill Creek, Gulch 8, Gulch 11, Gulch 19, Patsy Creek, Gulch 23 and Mill Creek. The North Fork extends into Central Belt Franciscan formation which result in grasslands and oak woodlands in the eastern portion of the basin. Slopes are steeper in the western part of this sub basin, particularly in the upper Little North Fork. Some information above is partially excerpted from habitat typing reports (GP, 1996). For more information about map images see Map Background pages.
Middle Ten Mile River Basin Description
The Middle Fork Ten Mile River is referred to as the Clark Fork in Georgia Pacific and Hawthorne Timber Company reports. Its elevations range from 140 feet (43 m) where it joins the North Fork to 3,000 feet in the headwater areas and drains approximately 21,400 acres (8661 ha). CFT is a tributary to the TMR with a confluence location of T20N R17W Sec25, 39° 33’53" N. latitude, 123°42’30" W. longitude on the USGS Dutchmans Knoll 7.5 minute quadrangle. Tributaries include Bear Haven Creek, Little Bear Haven Creek, Booth Gulch and Gulch 27. While the eastern portion of the Middle Fork watershed intersects slightly with Central Belt Franciscan, grasslands and oak woodlands are not extensive. As a result, the upper Middle Fork is much cooler than the upper North Fork. Bear Haven Creek is one of the largest tributaries. Some information above is partially excerpted from habitat typing reports (GP, 1996). For more information about map images see Map Background pages.
South Ten Mile River Basin Description
The South Fork Ten Mile watershed ranges in elevation from 20 feet at the mouth to 3,000 feet in the headwater areas and drains
approximately 19,620 acres (7940 ha). The confluence of the South Fork and the mainstem is only just in from the mouth at T19N R17W Sec03, 39° 32’23" N. latitude, 123°44’42" W. longitude on the USGS Dutchmans Knoll 7.5 minute quadrangle. Tributaries include Smith Creek, Campbell Creek, Churchman Creek and Redwood Creek. Some information above is partially excerpted from habitat typing reports (GP, 1996). For more information about map images see Map Background pages.
Coastal Tributaries North of the Ten Mile
The KRIS Ten Mile project includes nearby streams that flow to the Pacific Ocean to the north and south. The northern tributaries include Abalobadiah Creek, Seaside Creek, Frazer Creek and Wages Creek. The coastal plain is flat in the west of this sub basin but the Coast Range rises sharply to the east in headwater areas. For more information about map images see Map Background pages.
Coastal Tributaries South of the Ten Mile
The KRIS Ten Mile project includes nearby streams that flow to the Pacific Ocean to the north and south. This area is characterized by extensive dune habitats and small lakes sometimes occur in lower reaches of streams. Creeks include Lake, Mill, Inglenook and Virgin. For more information about map images see Map Background pages.
The map images you are seeing in the KRIS database are from a companion ArcView project called KRIS Ten Mile Maps. The map data is available on a separate CD and requires the program ArcView. Some themes are now also captured as ArcExplorer projects so that people without the more advanced software can at least review spatial data. Data in KRIS Map projects are an assimilation of information from many different sources. Please see the Map Background pages for more information.
Note about documents in KRIS
