Lockheed Fire Post Fire Risk Assessment
San Mateo-Santa Cruz Unit California Department of Forestry and Fire Protection
September 30, 2009
Aerial photo of Mill Creek drainage August 25, 2009
Table of Contents Page # Executive Summary 1 Introduction and Incident History 1 Watersheds 3 Field Observations 3 Burn Severity Characteristics 8 Fire Behavior 8 Historic Fire Return Intervals 9 Seasonal Context 10 Geology 12 General Observations 13 County Road 13 Downstream Impacts 13 Description of Geologic Units 16 Soils 17 Hydrophobic Soil Conditions 19 Soil Erosion Potential 20 Ecological Impacts 21 Redwood Forest 25 Mixed Conifer 25 Chaparral 26 Coastal Scrub 27 Grassland 27 Specific/Isolated Forest Stands 28 Invasive Species 29 General Recommendations 31 Recommendations to Mitigate Potential Soil Erosion and the Impacts 33 of Storm Water Runoff/Flooding Specific Observations 37 References 51 Post Fire Restoration Do’s and Don’ts 54 Firescaping and Erosion Control with Native Plants 59 Sample No Trespassing Sign 64
Maps Page # Watershed Map 6 Burn Severity Map 7 Fire History Map 11 Geology Map 15 Soil Map 18 Vegetation Type Map 24 Risk Maps Archibald Creek 40 Bettencourt Creek 41 Big Creek 42 Boyer Creek 43 Little Creek 44 Lower Scotts Creek 45 Mill Creek 46 Molino Creek 47 Queseria Creek 48 Upper Scotts Creek 49 Winter Creek 50
Tables and Charts Page # Table 1. Percent of Watersheds Burned 3 Table 2. Ranked Watersheds 5 Table 3. Fire Behavior 9 Table 4. Burn Severity by Vegetation Type 22 Chart 1. Lockheed Fire Severity by Vegetation Type 23 Chart 2. Vegetation Types by Burn Severity 23 Table 5. Generalized model of post-fire vegetation recovery for 27 chaparral Burn Site Evaluation Summary 61 Burn Site Evaluation Forms 66
Executive Summary
The Lockheed Fire started on August 12, 2009. During the emergency incident CAL FIRE officials determined that very high burn impacts occurred that could potentially impact lives and property. CAL FIRE assembled a multi-disciplinary team to do a rapid assessment of the fire area and identify critical risk areas. CAL FIRE also determined that local experts have a lot of knowledge from past fires and resource assessments that have been done in Santa Cruz County. This report attempts to bring together information and knowledge related to the potential post fire risks.
Based on the assessments made, eleven recommendations were formulated. The recommendations are listed in order of most immediately critical. The number one recommendation and highest priority is for the community accessed from Swanton Road to participate in Emergency Evacuation Planning. There is a significant increase in the potential for flooding, debris torrents, and debris flows in the watersheds affected by the fire. The number two recommendation is for the areas identified in this report as high risk areas to have site specific analysis conducted that prescribe practices to minimize risks.
Introduction and Incident History
The California Department of Forestry and Fire Protection (CAL FIRE) assembled a team to conduct a post burn assessment as part of its Emergency Watershed Protection (EWP) program authorized by Public Resources Code Section 4675 and 4676. The intent of activities conducted under this authority is to: 1) conserve water and soil, and 2) prevent destructive floods. This report is an assessment of the fire area that ranks high risk areas to life and property and recommends treatments to minimize risk.
This report is also a practical guide for property owners regarding recommended actions after a fire. The report contains summary information on watershed data regarding vegetation types, geology, soils and burn severity by watershed. This information can be used as a basis to conduct more detailed investigations and research within the burn area. The data for the maps were a cooperative project between Cal Poly Swanton Pacific Ranch, Big Creek Lumber Company, CAL FIRE and the U.S. Forest Service Remote Sensing Applications Center.
The Lockheed Incident (CA-CZU-007246) began on August 12, 2009. The incident was declared contained on August 23, 2009. The total acreage burned was 7,819 acres. The total suppression cost was over 30 million dollars. The fire burned across multiple private ownerships as well as a portion of California State Park property, all within State Responsibility Lands (SRA). The major landowners within the fire were Lockheed Martin Corporation, Big Creek Lumber, Cal Poly Swanton Pacific Ranch and CEMEX. The majority of the fire was located in the Scotts Creek Watershed, which supports anadromous fish bearing streams, with federally endangered coho salmon (Oncorhynchus kisutch) and federally threatened steelhead (Oncorhynchus mykiss).
Vegetation types in the burned area include redwood forest, mixed conifer forest, chaparral, coastal scrub and grassland. The landscape is mountainous with slope
Page 1 steepness commonly exceeding 50% (slopes range from nearly zero percent to over 90%). Crystalline igneous and sedimentary rocks that are moderately to pervasively fractured dominate the bedrock in the area. Burn severity across the entire burn area was estimated to be 14% very high, 37% high, 43% moderate, and 6% low.
On August 31, 2009, a team was assembled to develop a rapid assessment of the burned area watersheds. The objectives of the team were as follows:
1. Estimate the acreage and percent of area burned within each watershed affected by the fire and fire suppression activities. 2. Estimate the burn severity and create a burn severity map using the Burned Area Reflectance Classification (BARC) Map provided by the USDA Forest Service, post burn air photos and ground truthing. 3. Field check areas for hydrophobic soil conditions. 4. Estimate percent of area burned and severity by vegetation type. 5. Evaluate soil erosion potential. 6. Evaluate condition of roads, dams, bridges and culverts that may contribute to flood events (including Swanton Road). 7. Identify problem/risk areas. 8. Develop recommendations to mitigate potential high priority hazards. 9. Develop recommendations to assist restoration efforts.
The following technical specialists comprised the assessment team:
Angela Bernheisel, CAL FIRE, Forester Richard Casale, NRCS1, Erosion and Sediment Control Specialist Nadia Hamey, Big Creek Lumber, Forester Grey Hayes, PhD, Ecological Consultant Michael Huyette, CGS2, Engineering Geologist Rich Sampson, CAL FIRE, Division Chief
Additional experts who worked with the team to produce GIS maps were: John Martinez, CAL FIRE, Pre-Fire Planner Drew Perkins, Cal Poly Swanton Pacific Ranch, GIS Specialist Russ White, Cal Poly Swanton Pacific Ranch, GIS Specialist
1 U.S. Department of Agriculture, Natural Resources Conservation Service 2 California Department of Conservation, California Geological Survey
Page 2 Watersheds
The main drainages impacted by the fire are listed below (Table 1). All are tributaries to Scott Creek except Davenport Landing, Molino Creek, Picnic Creek and San Vicente Creek.
Table 1. Percent of Watersheds Burned Watershed Total Area Area Burned Area Burned (ac) (ac) (%) Archibald Creek 421 369 87.7 Bettencourt Subwatershed 3 495 494 99.8 Big Creek 5856 1447 24.7 Boyer Subwatershed 4 1354 432 31.9 Davenport Landing 2009 7 0.4 Little Creek 1306 1200 91.9 Lower Scotts Creek 1503 150 10.0 Mill Creek 2404 1626 67.6 Molino Creek 1025 797 77.8 Picnic Subwatershed 5 177 142 80.2 Queseria Creek 399 360 90.3 San Vicente Creek 6961 121 1.7 Upper Scotts Creek 5207 583 11.2 Winter Creek 116 94 81.0 Entire Scott Creek Watershed 19,001 6755 36%
Field Observations
The assessment team made field observations within and immediately adjacent to the Lockheed Fire. Field observations were completed from August 31st to September 2nd. Active suppression operations were still in progress. The team’s focus was to assess high risk areas for flooding and land sliding and to identify potential Emergency Watershed Protection Program projects. Tests for water repellency and hydrophobic 6 soil conditions were conducted at the field sites using a procedure suggested by the NRCS. Where homes or property were found to be at risk, a detailed form developed by the CGS was completed, including a detailed site description and/or photographs of the area.
The team utilized incident maps and other maps developed for the assessment. Lidar imagery of the Scotts Creek Watershed was provided by Cal Poly and Big Creek Lumber which was extremely valuable for the geological and hydrological assessments. The team
3 Bettenccourt Creek is separated from the Upper Scott Creek Watershed 4 Boyer Creek is separated from the Big Creek Watershed 5 Picnic Creek is separated from the San Vicente Watershed 6 Hydrophobic conditions result from a waxy substance that is released by plant material during a hot fire. This material penetrates into the soil as a gas and cools, forming a waxy coating around the soil particles (DeBano et al. 1998). Water repellency was evaluated by measuring the time it takes for water droplets to penetrate the soil both on and below the soil surface.
Page 3 also conducted informal interviews with residents of the fire area who provided information about past flood events and watershed conditions.
The Lockheed Fire Damage Assessment Report (2009) documented all structures observed within the burn and surrounding area where structures were defended. Road and foot inspections were conducted in the areas with high value from August 31 to September 2, 2009. Houses, in-stream structures such as dams, and road-related features, such as culverts and bridges, were surveyed at major drainage crossings. The portions of the burn area that drain into the San Vicente Creek and Davenport Landing watersheds were not evaluated due to their small relative percentage of burn area (1.8% and 0.4%, respectively) and the lack of known nearby values at risk. There is a major water intake for the town of Davenport above the confluence of Picnic Creek and San Vicente Creek. Above the intake 123 acres burned on the upper slopes as well as one spot within the channel (over 1 mile upstream from the intake). Firebreaks constructed along the edge of this watershed were evaluated during suppression repair and treated to prevent soil erosion.
The team identified risks to life and property from potential post-fire flooding, sediment concentrated floods, debris torrents, debris flows and future landslides from nearby slopes. The sites at risk are listed and described in Appendix A and B of this report. The descriptions of these sites vary, but a typical site was a home located within or just outside of the burned area, built across the discharge point of a steep watershed that was subjected to moderate to very high burn severity. The team identified 23 sites at risk, some involving multiple homes. There are likely additional sites at risk within and downstream of the fire area that were not specifically visited by the team.
Burn severity was evaluated in the field in several ways. Some team members flew over the fire area in a helicopter and photographed the post fire conditions on August 27th, the first day of good visibility over the fire area. Other members of the assessment team made ground based observations while assisting with suppression and suppression repair efforts over a large area of the fire. Then, specific data points were field assessed by the team st 7 during the week of August 31 . A BARC map provided by the Forest Service was used as a starting point for the burn severity map and was adjusted using field observations of all members of the team.
Table 2 contains the results of the burn severity assessments with the degree impact listed by watershed. The table also includes the acreage and percentage burned of each watershed. The rankings are based on the percent of the watershed that burned and percent of high and very high severity. Bettencourt Creek watershed, ranked number 1, has the largest percentage of the watershed burned and the largest percentage of very high and high severity within the burned area. Watershed boundaries and burn severity are also illustrated on the Burn Severity Map.
7 A Burned Area Reflectance Classification (BARC) is a satellite-derived map of post-fire vegetation condition. BARC maps are made by comparing satellite near and mid infrared reflectance values. Table 2. Ranked Watersheds Very Area Percent High Moderate Low of High Rank Watershed Burned Severity Severity Severity Watershed Severity (ac) (%) (%) (%) Burned (%) Bettencourt 1 494 100 25.3 46.0 25.8 2.9 Creek 2 Little Creek 1200 97 11.2 30.9 52.7 5.3
3 Archibald Creek 369 89 10.0 45.7 37.1 7.1
4 Picnic Creek 142 80 3.0 33.1 62.3 1.3
5 Molino Creek 797 77 7.9 44.2 39.2 8.3
6 Mill Creek 1626 68 25.0 38.1 32.6 4.2
7 Winter Creek 94 67 1.8 29.0 52.5 16.7
8 Queseria Creek 360 61 0.4 46.7 46.4 6.5
9 Boyer Creek 432 32 13.8 31.8 47.6 6.8
10 Big Creek 1447 25 15.2 36.3 45.0 3.5 Upper Scott 11 583 11 2.8 31.7 52.2 13.3 Creek Lower Scott 12 150 10 2.0 30.6 27.2 40.1 Creek San Vicente 14 123 1.8 0.6 12.7 70.4 16.1 Creek Davenport 13 7 <1 15.6 56.3 24.8 3.3 Landing
Page 5 Upper Scotts Creek
Boyer Creek
Mill Creek Bettencourt Creek
Big Creek
Lockheed Incident Lockheed Fire Post Risk Assessment Watersheds N Lower Scotts Creek LIttle Creek Picnic Creek Scale 1:45,000 Nad 27, California Teale Albers 0 0.5 1 Winter Creek Archibald Creek Miles Streams
Lockheed Fire Perimeter San Vicente Creek Roads Queseria Creek Molino Creek Watershed Boundary
Archibald Creek Bettencourt Subwater Big Creek Boyer Subwatershed Davenport Landing Little Creek Lower Scotts Creek Pacific Ocean Mill Creek Molino Creek Davenport Landing Picnic Subwatershed Queseria Creek San Vicente Creek Upper Scotts Creek Winter Creek Map created by: J. Martinez - 20090924
Page 6 Upper Scotts Creek
Boyer Creek
Mill Creek Bettencourt Creek
Big Creek
San Vicente Creek Lockheed Incident Lockheed Fire Post Risk Assessment Burn Severity N Lower Scotts Creek LIttle Creek Scale 1:45,000 Picnic Creek Nad 27, California Teale Albers Winter Creek Archibald Creek 0 0.4 0.8
Miles
Streams Queseria Creek Molino Creek Lockheed Fire Perimeter Roads Watershed Boundary Burn Severity Low Intensity Moderate Intensity High Intensity Pacific Ocean Very High Intensity Davenport Landing
Map created by: J. Martinez - 20090924
Page 7 Burn Severity Characteristics (adapted from Parsons, 2003):
Low: Surface fire with no extension into the tree canopy Slight or no modification of vegetation structure Nearly all mature plants survive Consumption of fine fuels and litter Unburned islands of vegetation remain Duff intact No or slight soil heating
Moderate: Long stems remaining in the chaparral Fire extension into the tree canopy of a small number of individual trees Moderate stand modification Most mature plants survive, but some mortality Needles on trees may be scorched Consumption of fine fuels and litter Duff layer partially consumed Some soil heating Some areas may be more of a mosaic of low to high severity that are lumped into the Moderate rating
High: Chaparral mostly consumed Most tree canopies scorched Most small plants, litter and duff consumed High mortality of mature plants, including trees Some larger diameter fuels remain
Very High: Chaparral consumption with many burned out stumps and burls Complete consumption of the tree canopies of the majority of the trees within an area Complete consumption of small plants, litter and duff Almost total consumption of mature plants May be significant soil heating
Fire Behavior
In order to better understand burn intensity patterns, fire behavior was estimated for the day the fire started under the weather and fuel conditions that were present. Five different fuel models, representing five vegetation types, were used in the BehavePlus computer simulation to estimate the fire behavior. The BehavePlus fire modeling system is a collection of models that describe fire behavior, fire effects and the fire environment. Many of these same fire models are used for FARSITE fire area simulator and FlamMap fire behavior mapping and analysis system. This simple BehavePlus output gives us information about the rate of spread in a specific fuel model from a point source ignition
Page 8 across a uniform fuel bed. We know that the burning conditions change across the landscape and that the following table represents the range of fire behavior that was observed in the beginning stages of the fire. The Behave program has been available since 1984 and is used extensively for prescribed burn planning and for getting quick results regarding the expected fire behavior on a wildfire.
Results of the analysis are presented in Table 3 and largely reflect the observed fire behavior during the first day of the fire. Readers are encouraged to be aware for the variability of fire behavior based on vegetation type in order to better prepare for future wildfires.
Table 3. Fire Behavior Rate of Rate of Heat per Fireline Flame Vegetation Fuel Spread Spread Unit Area Intensity Length Type Model (mi/hr) (ch8 /hr) (Btu/ft²) (Btu/ft/sec) (feet)
Grassland 1 2.5 198.7 84 305 6.3
Chaparral 4 4.2 337.3 2532 15,657 38.3
Coastal Scrub 5 1.0 80.0 467 685 9.1
Redwood Forest 9 0.6 47.3 344 298 6.2
Mixed Conifer 10 0.5 36.4 1214 811 9.8 Forest
Historic Fire Return Intervals
Prior to human-induced fires, the mean fire return interval in coast redwood (Sequoia sempervirens) stands was approximately 135 years; in chaparral, it was around 35 years (Greenlee 1990). These early fires ignited due to lighting strikes, which generally occur with moister air and onshore breezes, climatic conditions more conducive to cooler, less intense fires. During the eras of human-derived fire ignition, there was an increased frequency of fire, with fire return intervals in redwood forests of the Santa Cruz Mountains from 9 (Stephens and Fry 2005) to 80 years (Greenlee 1990). Native American burning substantially changed the landscape, shifting vegetation patterns through frequent, low intensity burns (Bean and Lawton 1993).
The last recorded and mapped fire perimeter within the Lockheed Fire area was for the Pine Mountain Fire in 1948 (61 years ago). Other large fires are known to have occurred
8 ch = chain. 1 chain = 66 feet and is a commonly used unit of measure in forestry and firefighting
Page 9 in the vicinity of the Lockheed Fire near the turn of the 19th century associated with logging and power generation projects in the Big Creek and Mill Creek Watersheds. A comprehensive review and collection of information available about historic fires in Santa Cruz County is not available beyond the past 50 years. It is only by luck that CAL FIRE was able to recover the burn perimeter for the Pine Mountain Fire.
Too infrequent fire return interval has been a concern in the Lockheed Fire area, evidenced by brush invasion in grasslands and tree invasion of shrublands; this trend has been widely documented in coastal California in recent decades (Callaway and Davis 1993). With greater fire return intervals in our Mediterranean ecosystems, excess fuels accumulation leads to greater fire severity when fires eventually occur.
Some types of chaparral have been disappearing as a consequence of fire suppression. As Douglas-fir and oaks overtake chaparral on the central coast, increased numbers of plants and animals are listed as endangered, spurring additional regulation and subsequent increased economic impacts (Van Dyke and Holl 2001). While hypotheses on historic fire return intervals in chaparral vary between 35-120 years, recent evidence suggests that fire return intervals for some species in certain types of maritime chaparral need be greater than 40 years for species conservation (Odion and Claudia Tyler 2002). This coincides with data suggesting that knobcone pines along the coast begin dying in mass approximately 60 years after a wildfire (Vogl 1973).
Seasonal Context
The Lockheed Fire took place in late summer, a season when lightning strikes can cause fires in the Santa Cruz Mountains. Within a few weeks of the fire, naturally-occurring lightning strikes were recorded in the vicinity. The seasonality of fire can drastically affect the impacts of the fire on native plant species composition (Howe 1994). The vegetation and wildlife in this region is not adapted to fires during the wet season. Seeds of herbaceous species, resistant to fire damage during the dry season, are easily destroyed by heat during the winter and spring. Fires that occur outside the summer fire season may also have negative impacts on native wildlife species.
Chaparral has a large diversity of native fungi (Parker, unpublished data), and conservation of this resource depends on fire occurring during the dry season as these species are more readily impacted by fire when the soil is moist (Dunn and DeBano 1977). Moist soil increases soil heating, reducing the capacity for plants to recover following fires during the wet season (LeFer and Parker 2005). The Lockheed Fire occurred when soils were dry, helping to buffer soil fungi and seeds from the high heat of the fire.
Page 10 Upper Scotts Creek
Pine Mountain Fire September, 1948
15,899 Acres Boyer Creek
Mill Creek Bettencourt Creek
Big Creek
Lockheed Fire August 12, 2009 7,817 Acres
Lockheed Incident Lockheed Fire Post Risk Assessment Fire History San Vicente Creek
LIttle Creek N Lower Scotts Creek Scale 1:45,000 Nad 27, California Teale Albers Picnic Creek Winter Creek Archibald Creek 0 0.4 0.8
Miles
Queseria Creek Molino Creek
Streams Lockheed Fire Perimeter Roads Watershed Boundary Historic Fire Perimeter
Pacific Ocean
Davenport Landing
Map created by: J. Martinez - 20090909
Page 11 Geology
The 7,819 acre Lockheed fire burn area is located in the Coast Range geomorphic province. The area contains several major bedrock units, collectively known as the Salinian structural block. These rocks are separated from different basement rock types to the northeast by the San Andreas Fault and to the southwest by the Sur-Nacimento-San Gregorio fault system (Clark, 1981). The Salinian block, is composed of granitic and metamorphic basement rocks, overlain by a sequence of marine sedimentary rocks of Paleocene and Pliocene age, non-marine sediments of Pliocene to Pleistocene age and locally overlain by quaternary deposits. A description of the geologic units (Brabb, 1997) within the Lockheed Fire area is included in the Description of Geologic Units – Key to Geology Legend following the map below.
Most of the burn area is underlain by Tertiary Santa Cruz Mudstone, which is described as medium to thick bedded, laminated siliceous mudstone grading to a sandy siltstone. As observed during this reconnaissance, and during numerous preharvest inspections for Timber Harvesting Plans that were in the area that burned by the Lockheed fire, the Santa Cruz Mudstone is highly fractured, hard, porcelainaeous shale and mudstone interbedded with siltstone and sandstone. Underlying the mudstone is the Tertiary Santa Margarita Sandstone and Paleozoic to Mesozoic quartz diorite and schist. The Santa Margarita Sandstone is described as very fine- to very coarse-grained sandstone (Clark, 1981; Brabb, 1997). The Santa Margarita Sandstone appears a relatively thin deposit surrounding exposed portions of the quartz diorite (see Geology Map and Description of Geologic Units).
Quaternary age alluvium underlies Scotts Creek and the lower portions of its larger tributaries. These deposits consist mainly of unconsolidated cobbles, gravel, sand and silt with varying amounts of boulders. Site soils, derived from the underlying geologic formation are described by Bowman and Estrada (1980) and are discussed in detail in the Soils Technical Specialist’s Report for this Risk Assessment. Generally, the soils form a thin cover on the ridge crests but form relatively deep deposits in the hillside swales and on the topographic benches in the burn area. The sandy loam and stony loam soils have abundant rock fragments and are characterized as well drained, moderately permeable and have rapid runoff. Where disturbed these soils have a moderate to high erosion potential.
Cooper-Clark and Associates (1975) map several, relatively large landslide deposits throughout the canyon side slopes of the burn area. Field observations of the burn area reveals that most of the existing landslide scarps were within the Santa Margarita Sandstone near its contact with the overlying Santa Cruz Mudstone and underlying quartz diorite. These slope-failure deposits include chaotic mixtures of soil and rubble and displaced bedrock blocks; most are debris slides and rock slumps or earth slumps. Landslides may or may not be active. They may be adversely affected over the long term as a consequence of fire removing intercepting and transpiring conifer and chaparral canopy and the loss of the reinforcing effect of roots. This affect may occur until the vegetation recovers.
Topography within the burn area ranges from gentle to very steep, with elevations ranging from about 200 feet above mean sea level near Scotts Creek along the southwestern
Page 12 margin of the fire to a high of about 1800 feet where the fire burned on a ridge spur between Scotts Creek and the ridge top of Ben Lomond Mountain. The burn area lies below the elevation generally subject to rain-on-snow events, although snow may occasionally fall near the higher peaks. Much of the mountainous portion of the burn area drains into numerous sub-watersheds that drain to the generally southwest flowing Scotts Creek near its outlet at the Pacific Ocean.
General Observations The principal concern with the Lockheed fire area is an increase in the potential for in- channel floods, hyperconcentrated floods, debris torrents, and debris flows. The primary mechanisms for this are increases in runoff resulting from reductions in interception resulting from the loss of live vegetation, reductions in infiltration due to the removal of duff and the dehydration of the soil, which is locally hydrophobic, from the simplification of surficial runoff patterns, and from the loss of mechanical support along stream channels. Also of concern is the long-term loss of mechanical support of hillslope materials that was provided by vegetation and vegetative litter. In the upper portions of the Mill Creek, Big Creek, Little Creek, Archibald Creek, Queseria Creek, Molino Creek, Bettencourt Creek and Boyer Creek, the fire burned hot and some hydrophobic soils have developed, where waxy substances released by plant materials during hot fires follow thermal gradients into the soil and congeal as continuous surfaces. Additionally the headwaters of these watersheds are very steep. Dry ravel (downslope mobilization of loose bedrock, soils, and sediment wedges accumulated behind vegetation removed during the fire) was observed on very steep slopes at various locations in the burnt headwaters. The loose materials may become mobilized into sediment laden masses during heavy rains, leading to the development of debris flows and debris torrents that may flow downstream from the watershed headwater source areas. The magnitude of post-fire damage will ultimately be determined by the intensity and duration of storms that impact the burn area, particularly during the winter of 2009-10.
County Road Numerous bridges, culverts, and other watercourse crossings are located along Swanton county road, near the downslope southwest fire perimeter. Many of these crossings will likely be impacted by sediment laden floods, debris flows, and debris torrents. Specific risks identified by the assessment team where flooding, debris flows, and debris torrents may impact the county road are described later in this report.
Downstream Impacts (flooding, sedimentation, debris flow) The habitable structures within, or at the mouths of Scotts Creek, Bettencourt Gulch, Mill Creek, Big Creek, Little Creek, Winter Creek, Archibald Creek, and Queseria Creek are downstream from the approximately 7,500 acres of the greater Scotts Creek watershed that burned. It is anticipated that flooding and sedimentation is likely to occur in these drainages during heavy winter and spring rains. The resulting downstream sedimentation and flooding may also impact infrastructure (for example agricultural systems, seepage systems, pumps, water lines, roads, watercourse crossings). The magnitude of post-fire damage will be determined by the intensity and duration of storms that impact the area. Although the Mill Creek Dam is upslope of the fire perimeter, it is understood that the Mill Creek dam has lost much of its capacity from previous flooding and a partial upstream side embankment failure. However, this dam and the reservoir area are maintained by Lockheed and are periodically inspected by the State.
Page 13
The reservoir behind a dam on Boyer Creek is mostly filled with sediment and the dam appears to be structurally impaired by embankment and spillway erosion from past overtopping events. Because the headwaters above the Boyer Creek dam experienced very high, high and moderate burn severity, there appears to be a possibility of increased runoff, flooding, and sedimentation to the Boyer Creek reservoir that could result in dam overtopping during moderate storms. If the Boyer Creek Dam were to fail, it would likely lead to flooding and debris flows and sediment concentrated floods that could impact down stream communities and infrastructure in Big Creek and the Lower Scotts Creek watershed. It is not clear if the dam is currently considered jurisdictional size by the State Division of Safety of Dams, but as with all risk sites in this report, it should be evaluated for its safety prior to the winter period.
The reservoir behind a dam on Molino Creek is partially filled with sediment and the dam appears to be structurally impaired with evidence of embankment and spillway erosion from past overtopping. As with Boyer Creek, the headwaters above the Molino Creek Dam experienced very high, high and moderate burn severity and there appears to be a possibility of increase runoff, flooding, and sedimentation to the Molino Creek reservoir that could result in overtopping during moderate storms. If the Molino Creek Dam were to fail, it would likely lead to flooding and debris flows and sediment concentrated floods that could impact the down stream Swanton county road.
Page 14 Upper Scotts Creek Tsc
qd Tsm
Tsm qd Boyer Creek
Mill Creek Bettencourt Creek qd Tsc qd
Tsc
Tsc qd Big Creek
Tsc
Tsm San Vicente Creek qd Tsc sch qd
Lockheed Incident Lockheed Fire Post Risk Assessment Geology
sch
Qcu Lower Scotts Creek LIttle Creek
Qal N Qcu Scale 1:45,000 Picnic Creek Qcl Nad 27, California Teale Albers qd Qcu Tsm Winter Creek Archibald Creek Tsc 0 0.4 0.8
Miles Qcu Streams Lockheed Fire Perimeter Qcu sch Watershed Boundary Queseria Creek Molino Creek m Qal Geologic Unit* Qcu Qal
Qbs Qcu Qcu Qcl Qcu Qcu Qbs Qcl Pacific Ocean Qal Tsc Qcu Qcu Qcu Tsm Davenport Landing m Qcu Qcu Qcl qd sch Tsc
* Refer to Description of Geologic Units Map created by: J. Martinez - 20090924
Page 15 Description of Geologic Units – Key to Geology Map Legend Qal - Alluvial deposits, undifferentiated (Holocene) Unconsolidated, heterogeneous, moderately sorted silt and sand containing discontinuous lenses of clay and silty clay. Locally includes large amounts of gravel. May include deposits equivalent to both younger (Qyf) and older (Qof) flood-plain deposits in areas where these were not differentiated. Thickness highly variable; may be more than 100 ft thick near coast.
Qbs - Beach sand (Holocene) Unconsolidated well-sorted sand. Local layers of pebbles and cobbles. Thin discontinuous lenses of silt relatively common in back-beach areas. Thickness variable, in part due to seasonal changes in wave energy; commonly less than 20 ft thick. May interfinger with either well-sorted dune sand or, where adjacent to coastal cliff, poorly- sorted colluvial deposits. Iron-and magnesium-rich heavy minerals locally from placers as much as 2 ft thick.
Qcl - Lowest emergent coastal terrace deposits (Pleistocene) Semi consolidated, generally well-sorted sand with a few thin, relatively continuous layers of gravel. Deposited in near shore high-energy marine environment. Grades upward into eolian deposits of Manresa Beach in southern part of county. Thickness variable; maximum approximately 40 ft. Unit thins to north where it ranges from 5 to 20 ft thick. Weathered zone ranges from 5 to 20 ft thick. As mapped, locally includes many small areas of fluvial and colluvial silt, sand, and gravel, especially at or near old wave-cut cliffs.
Qcu - Coastal terrace deposits, undifferentiated (Pleistocene) Semi consolidated, moderately well sorted marine sand with thin, discontinuous gravel-rich layers. May be overlain by poorly sorted fluvial and colluvial silt, sand, and gravel. Thickness variable; generally less than 20 ft thick. May be relatively well indurated in upper part of weathered zone.
Tsc - Santa Cruz Mudstone (upper Miocene) Medium-to thick-bedded and faintly laminated, blocky-weathering, pale-yellowish-brown siliceous organic mudstone. As shown, includes Santa Margarita Sandstone along Glenwood syncline. Thickness at least 8,900 ft in the Texas Company Poletti well near Waddell Creek (Clark, 1981, p. 31).
Tsm - Santa Margarita Sandstone (upper Miocene) Very thick bedded to massive thickly crossbedded yellowish-gray to white friable granular medium-to fine-grained arkosic sandstone; locally calcareous and locally bituminous. Thickness 430 ft along Scotts Valley syncline (Clark, 1981, p. 25). qd - Quartz diorite (Cretaceous) Grades to granodiorite south and east of Ben Lomond Mountain. sch - Metasedimentary rocks (Mesozoic or Paleozoic) Mainly pelitic schist and quartzite. m - Marble (Mesozoic or Paleozoic) Locally contains interbedded schist and calc-silicate rocks.
Page 16 Soils
Soil Types in Lockheed Fire Area According to the Soil Survey of Santa Cruz County9 (1980) published by the USDA Natural Resources Conservation Service (formerly Soil Conservation Service) the mapped soil types and approximate percent occurrences in the Lockheed Fire Area are listed below. The numbers preceding the soil name is the corresponding number on the Soil Map following.
151, 152, 153 Maymen Stoney Loam including rock outcrops (+/-40%) 113, 173 Ben Lomond/Catelli/Sur Complex (+/-35%) 167, 168, 169 Santa Lucia Loam (+/-7%) 142, 143 Lompico/Felton Complex (+/-6%) 117, 118 Bonny Doon Loam (+/- 4%) 182, 183, 184 Zayante Coarse Sand including rock outcrops (+/- 1%) 101, 100 Aptos Loam, Warm (+/- 1%) 146 Los Osos Loam (< 1%) 174, 175 Tierra/Watsonville Loam (< 1.0%) 135 Elkhorn Sandy Loam (< 0.5%) 136 Elkhorn/Pfeiffer Complex (<0.5%) 171 Soquel Loam (< 0.5%) 185 Water Bodies (< 0.5%) Other soils as inclusions or as mapped-various (+/- 2%)
It is important to note that approximately 75% of the soils mapped in the Lockheed Fire area are in one of the following soil series: Maymen (including rock outcrop); Ben Lomond; Catelli; or Sur series soils. In addition, all of the mapped soil types within these series, including a percentage of the remaining mapped soil types in the fire area, occur on 30% or greater slopes.
Several soil samples were taken and analyzed using a “feel” soil texture method in the burn area to verify the mapped soil type. Although the number of samples was not great because of the availability of time to carry out a more detailed assessment, in nearly every instance the soil was correctly mapped.
9 Information contained in the Santa Cruz County Soil Survey should not be used in place of an on-site soils investigation if specific soil information is needed in the design of or reconstruction of roads, buildings or other structural improvements. Soil survey information is intended for general planning purposes and is not a substitute for a soil engineering report or a site-specific soil evaluation. Soil mapping done in Santa Cruz County was done utilizing a combination of field observations and aerial/topographic surveys and other remote sensing and mapping tools. Although thousands of soil samples were taken and analyzed to determine exact soil types in the 1980 survey area, samples were not taken in every single soil mapping unit that appear on the soil survey soil map. Soils mapped in mountainous areas are less exact than soils mapped in agricultural areas including rangeland. The soil survey narrative does list other associated soils that might also be found in the mapped area. It is also possible that other unlisted soils may be present as well. It is important to keep in mind that soil boundary lines on the small scale maps can be as much as 30- 40 feet wide in the field and therefore should be considered a zone rather than a line on the land.
Page 17 Upper Scotts Creek
Boyer Creek 113
Mill Creek 142 Bettencourt Creek 113 153 171 113 173
173 171 113 113 113 142 185 171 153 118 182 146 183 142
169
168 173 Big Creek 118 153
171 117 100 153 171 100 100 153 168 168 142 171 167 168 100 182 117 168 117 113 168 169 142 142 143 Lockheed Incident Lockheed Post Fire Post Risk Assessment Soils 143 171 142 113 169 173 113 153 142 168 Lower Scotts Creek 117 N LIttle Creek San Vicente Creek Picnic Creek 175 117 151 142 Scale 1:45,000 113 169 167 169 Nad 27, California Teale Albers 153 113 151 184 153 0 0.4 0.8 Winter Creek Archibald Creek 113 142 184 167 Miles 168 101 113 113 100 100 Streams 151 142 Lockheed Fire Perimeter 153 153 174 169 152 Watershed Boundary Queseria Creek 118 Molino Creek Soil Types 142 153 100 153 117 101 167 113 117 168 135 136 117 169 153
118 171 171 171 Pacific Ocean 118 117 135 173 136 174 142 175 Davenport Landing 143 182 146 183 151 184 152 185 * Refer to Description of Soil Types Map created by: J. Martinez - 20090924
Page 18 Hydrophobic Soil Conditions Soils were tested in the field throughout the burn area to determine if hydrophobic soil conditions 10 exist.
When present, the hydrophobic layer was generally at the surface below the ash layer (if ash was present) and varied to an approximate depth of 2 inches beneath the soil surface. The depth of wettable surface above the hydrophobic layer varied between 2 inches and no apparent wettable surface. Typically, the hydrophobic layer was less than 1 inch thick, although there may be some instances in severely burned areas where the hydrophobic layer is more than an inch thick. The continuity and thickness of the layer varied across the landscape and from test site to test site. The variation is most likely a factor of burn severity, amount and type of burned vegetative cover and ground litter, soil type, amount of soil organic matter, physical disturbance of soil by fire fighting efforts and/or possibly other factors.
Most of the soils tested for hydrophobic condition were in the upper watershed areas on steeper slopes (15% to 30% or higher) and where soils were very shallow with little actual soil content/ development. In most of the soil testing areas Maymen soil was the predominant soil type exhibiting only weak to moderate water-repellency as a result of the soil being hydrophobic. In several cases there was no detectable hydrophobic layer. In all cases the hydrophobic condition was present within 2 inches of the surface (as mentioned above) if it was present at all.
In a few instances strong water-repellency was found in the soil. These test sites were located where there was significant soil development, a deeper soil profile, previous dense vegetative cover and litter and where there was a high soil burn severity. Prior to the fire it is likely that some degree of hydrophobic conditions existed in the soils particularly in the chaparral areas. No pre-fire sampling data is available for the fire area. Pre-fire hydrophobicity would not be expected to be as strong as conditions observed post fire. But it should not be concluded that all hydrophobic conditions observed are a result of the fire.
The amount of vegetative cover, woody material, soil texture, soil crusting, surface rocks, and slope of the land should be considered in any proposed restoration work. The combination of these factors along with the extent and thickness of the hydrophobic layer determine the likelihood of increased runoff, overland flow, erosion, and sedimentation. Thicker hydrophobic soil layers can persist for more than a year and will continue to have an impact on infiltration as well as plant growth. Plant roots, soil micro- organisms, and soil fauna and any soil/land disturbance activities will break down the hydrophobic layer over time.
10 Soils that repel water are considered hydrophobic. A thin layer of soil at or below the mineral soil surface can become hydrophobic after intense heating. The hydrophobic layer is the result of a waxy substance that is derived from plant material burned during a hot fire. The waxy substance penetrates into the soil as a gas and solidifies after it cools, forming a waxy coating around soil particles. The layer appears similar to non- hydrophobic layers. Plant leaves, twigs, branches, and needles form a layer of litter and duff on the forest floor and under chaparral and shrubs. During the interval between one fire and another, hydrophobic substances accumulate in this layer. During an intense fire, these substances move into the mineral soil. Soil Erosion Potential Runoff is rapid and erosion hazard is high to very high on nearly all soils within the fire containment area and especially where slopes are greater than 15% and/or where soil and vegetation has been destroyed or damaged by fire or disturbed by fire fighting efforts. The erosion hazard can be even higher where root systems have been destroyed, bare soils exist, pre-existing eroded/unstable slope conditions exist, and/or on excessively steep slopes (>30%), which represents 75% or more of the land area within the fire perimeter.
Over 90% of the mapped soils in the fire area have a moderate (0.6-2.0 inches per hour) or moderately rapid to rapid (2.0-6.0 inches per hour) permeability/infiltration rate and are well drained to excessively drained under pre-fire conditions. Soil permeability and infiltration rates are compromised and usually decrease following fire by one or more of the following factors: presence and depth of ash on the soil surface; amount of post fire ground protection in the form of plant material (burn and unburned); leaf litter; amount of rock/shale fragments in surface soil; amount of soil organic matter; presence of hydrophobic soil layer; compaction from fire fighting equipment and ground effort; and compaction and dispersion of fine soil particles from direct impact of rainfall causing sealing of the surface soil. In fact, in higher soil burn severity areas there is likely an increase of soil sealing because organic matter has been reduced and soil aggregate stability has been compromised that also causes dispersion of finer particles and the filling of soil pores/voids at the surface.
Both soil sealing and hydrophobic conditions will likely result in increased runoff, an increased hazard of down slope soil erosion and resultant sedimentation, and increase the potential for downstream flooding, especially where there is an absence of an ash layer 11, plant cover, leaf litter or other surface soil protection. The degree of ash benefit in protecting the soil from erosion will vary depending on the continuity and depth of the ash, soil type, steepness and configuration of slope. Slope configuration (swales, dips, hollows, ephemeral channels in the slope) can produce opportunities for accelerated and/or concentrated flow that will displace ash and reduce soil protection. In some instances the hazard of soil erosion on post fire hydrophobic soils is lower because the water repellent layer is less erosive.
Other factors that can contribute to soil erosion, sedimentation, flooding and other related issues following wild fire include: 1. Soil type and condition, including, coarser texture soils, granular structure, hydrophobic characteristics, soil sealing, crusting, compaction, low fertility, amount of soil organic matter, etc. 2. Geology and topography. Geologic rock type, earthquakes, geological faulting, steepness and length of slope, etc. 3. Lack of, or inappropriate vegetative cover 4. Lack of surface litter in the form of leaves, needles, twigs, small stones, etc. 5. Intense rainfall and/or soil saturation conditions caused by prolonged rainfall events 6. Soil or slope disturbances either natural or human induced. 7. Uncontrolled runoff from structures, roads, and other impervious surfaces.
11 Recent studies conducted by Colorado State University and published in the July-August 2009 Journal of the Soil Science Society of America suggest that runoff can be reduced by as much as 49% and sediment reduced by as much as 67% on burn sites with ash cover.
Page 20 8. Trails, walkways or other access routes and any inappropriate hand-made channels or diversion ditches (including water bars, rolling dips, etc.) that may intercept and channel runoff and contribute to erosion or other related problems. 9. Bare and disturbed soil conditions in fire area or within the watershed on neighboring lands, including drainage alterations and other land use changes that contribute drainage/runoff toward areas of concern, especially during the winter months. 10. High and/or accelerated flows in streams and other waterways causing channel down cutting and bank erosion. 11. A combination of any number of factors above.
Some possible impacts or consequences associated with vegetation/soil/slope disturbances from wild fire include: 1. Debris flows and downstream flooding 2. Potential slope instability. 3. Damage to vegetative cover and fish & wildlife habitat within and outside the fire perimeter. 4. Accelerated soil erosion, including: raindrop splash, sheet, rill, gully and streambank erosion. 5. Potential property owner liability if increased runoff or sedimentation causes damages or issues for neighboring down stream property owners or important water courses if inappropriate actions and/or measures are taken/installed on fire affected lands. 6. Degraded landscape appearance. 7. Lower property values, including loss of crops, timber products, etc. 8. Creation of potential safety hazards. 9. Expense to restore property and improvements damaged by wild fire and any fire fighting soil/slope/water course disturbance activities.
Ecological Impacts California’s large varied landscape and its Mediterranean climate combine to create widely varied fire regimes that have been important in shaping the state’s remarkable plant species diversity. Mediterranean ecosystems are prone to fire due both to prolonged summer droughts as well as cyclical multi-year droughts, which lead to plant stress and mortality. Therefore, during the late summer, much of California is a dry landscape replete with large amounts of dead biomass. And yet, California is so large and so complex as to present a diverse geography with diverse fire regimes.
Fire regimes vary from the north to the south of the state, due to differences in population density, rainfall, vegetation, and wind patterns. Regimes also vary from the east to the west in response to maritime influence; fog prevalence and cooler temperatures along the coast reduce the frequency of naturally occurring fire. Geographic and climatic variations and consequent variation in fire regimes create a complex relationship between fire and plants. As natural fire return intervals and intensities vary, so do plant species’ adaptations to fire; the distribution of plant taxa reflect these adaptations.
Plant species cope with the destructive effects of the wildfires with such diverse adaptations as: dormant buds, lignotubers (burls), and long term seed banks that are triggered by the heat or chemicals from fire (Margaris 1981). Eruptions of surprisingly widespread wildflowers and germination of fire dependent plant species are commonly recognized fire-related botanical phenomena. Indeed, many of California’s most recognized trees and shrubs rely on fire to produce a new cohort of healthy offspring. While some plant species require multiple complex fire-related cues to germinate (Keith 1997), the germination of many species has been linked to a small set of chemicals released from smoke and charcoal (Keeley and Fotheringham 1997, Roche et al. 1997).
In fire adapted plant communities, fire is an essential factor in maintaining plant species diversity over time. For example, fire-adapted forests that have experienced wildfire have been shown to have more plant species diversity than unburned areas (Peltzer et al. 2000). After the 2008 Summit and Martin fires, large populations of previously undocumented and rare species appeared in mass over large areas. These included masses of Phacelia and Lotus species that occur following a fire. At the Martin Fire, declining populations of rare species such as the Ben Lomond wallflower (Erysimum teretifolium) and Bonny Doon spineflower (Chorizanthe pungens hartwegii) recovered to larger populations than seen anytime recently.
Fire also plays an important role in nutrient cycling. Intense fires will volatilize nitrogen, but will make other nutrients that are otherwise sequestered in dead or live biomass available for fire recovery (Dunn and DeBano 1977, Debano and Conrad 1978).
Table 4. Burn Severity by Vegetation Type 12 Area Burned Very High High Severity Moderate Low Severity Vegetation Type (ac) Severity (ac) (ac) Severity (ac) (ac)
Redwood Forest 2420 43 594 1648 135
Mixed Conifer 1951 93 699 1107 52 Forest
Chaparral 2425 920 1207 276 22
Coastal Scrub 535 17 306 195 17
Grassland 342 0 54 22 266
Agriculture 42 0 10 28 2
Monterey pine 37 0 17 18 2
Quarry/Town 4 0 0 1 3
Oak Woodland 15 0 3 12 0
12 The total acreage of vegetation types by severity is 7771 acres as compared to the mapped burned acreage of 7819. Minor discrepancies occur with the burn severity and vegetation type GIS layer acreages. Chart 1. Lockheed Fire Severity by Vegetation Type
90%
80%
70%
60%
50% Very High High Moderate 40%
Percentage Low
30%
20%
10%
0% redwood mixed conifer chaparral coastal scrub grassland Vegetation Type
Chart 2. Vegetation Types by Burn Severity
90%
80%
70%
60%
redwood 50% mixed conifer chaparral 40% coastal scrub grassland
Percentage of Veg Type Veg of Percentage 30%
20%
10%
0% Very High High Moderate Low Severity
Page 23 Upper Scotts Creek
Boyer Creek
Mill Creek Bettencourt Creek
Big Creek
Lockheed Incident Lockheed Fire Post Risk Assessment Vegetation San Vicente Creek N Lower Scotts Creek LIttle Creek Scale 1:45,000 Picnic Creek Nad 27, California Teale Albers Winter Creek Archibald Creek 0 0.4 0.8
Miles
Streams Lockheed Fire Perimeter Queseria Creek Molino Creek Roads Watershed Boundary
Agriculture Chaparral Coastal Scrub Grassland Mixed Conifer Pacific Ocean Monterey Pine Davenport Landing Oak Woodland Quarry/Town Redwood
Map created by: J. Martinez - 20090924
Page 24 Redwood Forest Redwood dominated stands occupy 2420 acres (31%) of the Lockheed Fire. The highly evolved ability of coast redwoods to resist fire and recover from fire effects (Fritz 1931) is unusual amongst conifers (Stephens and Fry 2005). Even smaller diameter trees are able to resprout after canopies are destroyed (Finney and Martin 1993). This resilience, along with the important ecological role of fire in maintaining habitat diversity, nutrient cycling and wildlife habitat creation, suggests that the Lockheed Fire will not have long term detrimental ecological effects to the redwood forest type.
However, in managed forestlands (which encompass several thousand acres of the fire) significant loss of commercial value is expected as a result of fire scar defect introduced in redwood and Douglas-fir trees coupled with subsequent biotic stressors. These scars are also more vulnerable to prolonged burning when the area experiences fire again. In some areas, depending on fire severity and species composition, tree growth potential will be reduced in the short term as regeneration occurs and limbs sprout back.
Fire plays an important role in maintaining the diversity associated with redwood stands. Fires have been shown to arrest tanoak (Lithocarpus densiflorus) growth in redwoods (Hunter et al. 1999), which may help in maintaining the plant diversity characteristic of more open redwood stands including redwood sorrel (Oxalis oregana), violets (Viola spp.), and various lily relatives (Liliaceae).
Old growth redwood stands, and perhaps stand structure more typical of later successional redwood forest, are thought to be more resistant to detrimental effects of fire. In more northern areas of California, only four percent of old growth trees have been lost in higher severity fires (Fritz 1931). Young, even aged stands of redwoods may be more susceptible to death due to wildfire than the uneven aged stands fostered by selective forestry (Namkoong and Roberds 1974).
The Lockheed Fire resulted in moderate burn severity through most of the redwood stands (see Table 4). Many large diameter redwood trees were scorched throughout the fire, and will likely survive. The severity of fire effects on redwood stands increased with elevation and distance from the ocean: stands along lower reaches of perennial streams were subject to the least fire severity whereas stands on ridgelines were more highly impacted. Because little soil mulch remained in any area of the fire, there was a very large extent of bare or near bare mineral soil, which is necessary for redwood seedling establishment. Recruitment of seedlings is expected to be high near seed sources.
Common plants of the redwood understory will probably be much reduced in the near future, though will likely recover quickly. These include: redwood sorrel, sword fern (Polystichum munitum), California blackberry (Rubus ursinus), modesty (Whipplea modesta), and poison oak (Toxicodendron diversilobum).
Mixed Conifer Douglas-fir (Pseudotsuga menziesii) is a co-dominant with coast redwood in stands that are located primarily higher up on slopes in areas with greater burn severity. Mixed conifer stands comprise 1951 acres (25%) of the Lockheed Fire area. These stands are generally higher in elevation on slopes and mixed within redwood dominated stands described above. Less severe fires or thinning are necessary to more quickly develop old growth
Page 25 characteristics within Douglas-fir forests (Zenner 2005). Regeneration of Douglas-fir is limited by dispersal distance from cone bearing trees. Establishment of seedlings is expected to occur during the first four years after the fire (Donato et al. 2009).
In the case of large-scale dense reestablishment of the species, small mammal populations could suffer due to lack of plant community diversity. In this case, post fire thinning of dense stands of Douglas-fir may assist with recovery of small mammals (Suzuki and Hayes 2003). The fire removed large amounts of coarse woody debris, which is important for some species of small mammals using forested habitats containing Douglas- fir (Ucitel et al. 2003).
In general, there is probably enough remaining Douglas-fir throughout the extent of the fire to provide seed source to regenerate new stands. Where there was significant loss of the species, dead trees will serve as habitat for the many wildlife species that benefit from snags or, in the longer term, from coarse woody debris on the forest floor.
Chaparral The seasonality of fire can drastically affect the impacts of the fire on native plant species composition (Howe 1994). Chaparral has a large diversity of native fungi (Parker, unpublished data), and conservation of this resource depends on fire occurring during the dry season as these species are more readily impacted by fire when the soil is moist (Dunn and DeBano 1977). In addition, many chaparral shrubs are negatively affected by the heat of fire when the soil is moist, reducing their capacity to recover following fires during the wet season (LeFer and Parker 2005). The Lockheed Fire occurred when soils were quite dry, helping to buffer soil fungi and seeds from the high heat of the fire.
86% of the very high and 42% of the high severity burn were in chaparral communities dominated by manzanita with or without an overstory of knobcone pine.
Of all of the habitat types affected by the Lockheed Fire, chaparral is the most clearly responsive to fire. Chaparral has been proposed to serve as a fire indicator system with a mixture of critical fuel loads and biological response times bracketing fire return intervals to better inform fire managers. The Martin and Summit Fires in 2008, as with this fire, initially spread through the chaparral before burning through other forest types.
Mature chaparral consists of a few woody species that depend on fire to regenerate, especially at germination and seedling establishment (Keeley and Keeley 1981). Knobcone pines are an overstory species in much of the maritime chaparral of the Lockheed Fire. This tree is also fire dependent (Williams 1989), with cones that only open in extreme heat (>200°F) releasing seeds in the weeks and months following a fire (Vogl 1973). Knobcone pine seedlings establish mostly during the first year post-fire (Donato et al. 2009).
Following the typical canopy destroying fires of chaparral, there are a series of plant communities before the pre-fire dominance of chaparral shrubs (Table 5) (Keeley and Keeley 1981, Tyler 1996). After many years without fire, the chaparral shrubs succumb to oak and conifer invasion.
Page 26 Table 5. A generalized model of post-fire vegetation recovery for chaparral Plant type Establishment Years to dominance mechanism Annual forbs Seeds 1-3 Perennial grasses Seeds 3-8 Herbaceous perennials Seeds/resprout 13 3-12 Woody shrubs Seeds/resprout 12+ Conifers Seeds/resprout 20+
Many of the chaparral species regenerating after fire do so in pre-fire canopy gaps, where there is reduced intensity of the fire (Odion 1995). And yet, high intensity burns are necessary for maritime chaparral communities to persist over the long term. Lower intensity fires may allow less fire tolerant species such as oaks and Douglas-fir to survive and eventually displace the chaparral (Florence 1986).
Coastal Scrub 533 acres of coastal scrub were burned in the Lockheed Fire with mostly high to moderate fire severity effects.
Two distinct types of coastal scrub were evident before the fire: a generally species- diverse type on near vertical, south-facing, low-elevation, shallow soiled slopes and a generally species-poor type as an early successional community invading grasslands. Because of the slope position, the former was subjected to higher fire severity. There were significantly fewer acres of the latter, which resulted in the more moderate burn severity.
Both systems are expected to recover, though the species richness of the former is expected to be somewhat decreased in the short term. The grassland type coastal scrub will recover quickly without further management effort.
In the absence of fire and grazing, grasslands throughout the region are increasingly being invaded by coyote brush (Baccharis pilularis) (Callaway and Davis 1993), significantly increasing the danger of higher intensity fires (Russell and McBride 2003). Many land managers in the area in and around the fire regularly maintain grasslands to eliminate brush invasion. However, the meadows near the southern boundary of the wildfire are extensively invaded by coyote brush, which is expected to resprout readily after the fire.
Grassland The grasslands within the fire, also known as coastal prairie, were a minor portion of the fires extent covering 342 acres (under 5% of the fire area). Although there are many types of coastal prairies, from the wildflower-rich near vertical hillsides to more deep-soiled and generally species-poor terraces, fine scale mapping with which to apply GIS analysis has not been done for this project. 77% of the grasslands that burned were of low severity. Generally the fire did not produce enough residence time in the grasslands to have a high burn severity.
13 Resprout: refers to sprouts formed from various tissue, including basal burl, underground growth buds, stems, etc
Page 27
Although fire has been an important factor in maintaining coastal prairies, the Lockheed Fire is only minimal factor influencing the long term health of the coastal prairie. Historically, of all the vegetation types affected by the Lockheed Fire, fire most frequently occurred in coastal prairie. The Native Americans and the early ranchers used fire extensively and frequently to manage grasslands (Greenlee 1990, Bean and Lawton 1993). Fire consumes mulch (Meyer and Schiffman 1999, Jutila and Grace 2002, Harrison et al. 2003), which inhibits the growth and germination of a diverse array of native grasses and wildflowers including the more common native bunchgrass, purple needlegrass (Nassella pulchra) (Fossum 1990, Dyer et al. 1996). But, because mulch quickly accumulates again, the effects of fire are short-lived, and species diversity quickly returns to pre-fire conditions (D'Antonio et al. 2004). Another of the common coastal prairie bunchgrasses, California oatgrass (Danthonia californica) may be more resilient to mulch build up and is therefore less affected by fire or lack of fire (Hatch et al. 1999). But, experimental work on most coastal prairie species has been limited to few sites, and scientists warn that fire effects on plant species may vary greatly depending on the site (Seabloom et al. 2003, Bartolome et al. 2004). On the landscape scale, fire plays an important role in maintaining grassland habitat structure by reducing woody cover, (e.g. coyote brush, Baccharis pilularis) and thereby helping to maintain grassland dependent species (Clark and Wilson 2001). However, fires must occur at relatively close intervals to effectively reduce woody species. This has been observed on successive prescribed burn areas at Wilder Ranch State Park and other grassland burn areas with invading coyote brush.
Specific/Isolated Forest Stands Three forest stand types are addressed because of distinct conservation concerns: Monterey pine, tan oak, and live oak. Affects of fire vary somewhat between these types and opportunities and concerns are likewise specific to each stand type.
Monterey Pine Stands A small area of native Monterey pine was affected by moderate intensity fire. The fire in this area was spotty and created neither the bare soil nor the high light levels necessary for significant recruitment of a new generation of trees. Neither was there significant loss of adult trees.
Larger areas of Monterey pine plantations were affected by the fire and may lead to recruitment of this genetically dissimilar stock. The generation of sizeable numbers of non- native stock continues an ongoing threat of genetic introgression/contamination of the native tree stands that lie in close proximity.
Live Oak Stands including Shreve Oak (Quercus parvula shrevei), Coast (Q. agrifolia), Interior (Q. wislizenii) and Canyon Live (Q. chrysolepis) Oaks Live oak stands were mostly peripheral to the most intensely burned areas. While nearly every live oak within the fire boundaries suffered near total leaf loss, very few trees will be lost.
There were minor fire effects on two live oak species that were mostly found in lower elevations of the fire – Shreve and coast live oak. Fire did not affect either of the two significant stands of Shreve oak at Swanton Pacific Ranch, below the Al Smith House.
Page 28 Smaller Shreve oak stands were more affected elsewhere, such as in the Little Creek, Archibald, Winter Creek drainages, and competition from the conifers beginning to dominate some stands may be altered by the fire (i.e. some conifers may be fire damaged and less competitive).
Coast live oaks formed a perimeter on most of the meadows and are frequent components of many lower-elevation mixed coniferous forest; these experienced moderate fire intensity with a high rate of oak survival expected. There is some evidence that the threat to this species from sudden oak death (Phytopthera ramorum) may be reduced due to fire.
Two other oak species were much more affected by the fire – Interior and canyon live oak. Interior live oaks were found in and around higher elevation maritime chaparral ridges; there were mixed burn severities and affects to this species. Most of the canyon live oak found within the fire was a shrubby form within the maritime chaparral complex. These were intensely burned along most chaparral covered ridges. The circumference of shrubby canyon live oak burls (indeed, rings of burls) suggests many prior exposures to wildfire and a strong chance that many individuals will persist. In some areas, these wide burl rings appear to be a strong slope stabilizing force, replete with relatively high soil mounds.
Tan Oak Stands There were extensive tan oak stands throughout the fire, especially at higher elevations in most drainages, just below the more chaparral covered ridges. Because of adjacency of these stands to maritime chaparral, they experienced relatively high fire intensity. The understory of these stands is typically quite species poor, with a thin leaf litter layer and little coarse woody debris. Post fire, the understory of these stands was severely burned with no ground cover and little remaining woody debris. Nearly all trees had complete leaf loss, though dead leaves remained attached to the stems at the time of survey.
There is little literature on tan oak in general and the species’ response to fire in specific. While scientists note that tan oak resprouts readily after wildfire (Shatford et al. 2007), the level of fire intensity that tanoak stems can tolerate has not been quantified. Fire may not present the best scenario for tan oak dominance; tan oak generally increases more in the absence of fire, at it is an excellent competitor in shaded forest (Hunter et al. 1999). Sudden exposure to light, as with after fire damage to surrounding canopies, results in sunlight damage to tan oak canopies (McDonald 2009).
The response to these stands to the Lockheed Fire presents great uncertainty, with multiple potential outcomes including large scale loss of stands, rapid resprouting of individuals from trunk bases or stems, or perhaps expansion and release of many small established trees in areas previously occupied by Douglas-fir.
Invasive Species The post fire environment presents significant opportunities for increased establishment of exotic invasive species including increased light levels, reduced competition, exposure of bare mineral soil and increased seed dispersal opportunities (animal, soil, etc). Fire increases invasive grass abundance (Hughes and Vitousek 1993). Increased abundance of nonnative grasses can then lead to increased fire frequency (D'Antonio and Vitousek 1992), creating a potentially vicious cycle. While ongoing disturbances along road and fire
Page 29 break corridors may present the more common concern with the invasive annual grasses typical of much of California, other species are focused upon here to highlight perhaps more pressing and immediate concerns. Managers in the region report specific concerns with two species for large areas of the fire: jubata grass, also called pampas grass, (Cortaderia jubata) and French broom (Genista monspessulana). Other species of concern include: thistles (Cirsium, Silybum, and Carduus spp.) and iceplant (Carpobrotus spp.).
Because of proximity of seed sources, jubata grass presents the greatest invasive species hazard across the range of the fire. Significant stands of the species persist in the Highway 1 corridor as well as on private lands surrounding and within the fire footprint. Jubata grass establishment is limited by light: the species only establishes where light reaches the soil surface. And so, the fire has opened extensive new acreage for invasion, presenting a substantial challenge to land managers.
Patches of French broom were widespread throughout the Lockheed Fire area before the burn. Fire has been shown to affect French broom seed banks in two ways – reducing the seedbank overall (Alexander and D'Antonio 2003) and increasing the germination of any remaining viable seeds (LeFer and Parker 2005). Seeds were probably spread along roads used during fire suppression. Additional seed dispersal will be facilitated during unusually high erosion events after the fire.
Thistle species in a number of genera commonly respond positively by increasing cover and expanding in geographic scope following fire. Bull thistle (Cirsium vulgare) has persisted in grassland areas through the fire (Jim West, pers. comm. and personal observation); the species expected to increase both in grasslands and in any adjoining areas post fire. Milk thistle (Silybum marianum) and bull thistle will likely proliferate in areas of fire retardant application where seedbank existed previously or where seeds can disperse into these areas before native canopy cover is established. Italian thistle (Carduus pycnocephalus) and tocalote (Centaurea melitensis) were ubiquitous before the fire and will likely have short term expansions in population numbers and cover.
Iceplant has been shown to invade maritime chaparral more easily after fire (Zedler and Scheid 1988, D'Antonio et al. 1993), though the species does not disperse great distances. Populations within the fire perimeter are not known, though land managers should be aware of the potential for invasion of this species post fire.
Page 30 General Recommendations14
1. Conduct Emergency Evacuation Planning All residents that live in the community accessed from Swanton Road should participate in Emergency Evacuation Planning. Emergency Response agencies (CAL FIRE, Santa Cruz County Office of Emergency Services and Santa Cruz County Sheriff Department) will prepare the plan and implement the plan. Rainfall, soil saturation and stream level monitoring should be included in the plan.
Some sources for key information include: Cal Poly Little Creek Study monitoring sites and data, National Weather Service resources (weather statements, Advisories, Watches and Warnings, and short-term forecasts (NOWcasts), for significant/severe weather events and flooding), Ben Lomond Remote Automated Weather Station15, Big Creek Fire Station rain gauge, FEMA guidance16, Cal Poly radio communications system and Santa Cruz County Amateur Radio Emergency Service. The Santa Cruz County Office of Emergency Services manages the Early Alert System under the Federal Communications Early Alert System Plan for Monterey Bay Area17 . La Honda Fire Brigade has prepared an evacuation plan for the Central La Honda Community and may be available to offer advice or assistance with the plan for Swanton Community. San Diego County has prepared a Homeowners’ Guide for Flood Debris and Erosion Control After Fires18 that may be helpful.
2. Conduct Site Specific Analysis for High Risk Areas Consult with experts to assist with developing site specific mitigations. For high risk locations listed under “Specific Observations” below a Certified Engineering Geologist19, Certified Hydrologist or Professional Engineer experienced in the analysis of post fire issues should be consulted to determine site specific measure to be employed. The water intake in San Vicente Creek should also be inspected for potential impacts as a result of the fire. For issues related to soil erosion and increased runoff consult with a Certified Professional in Erosion Control and Sediment 20 For issues related to hazard trees and forest health mitigations consult with a Registered Professional Forester (RPF).21 Other experts in the areas of landscape design and native plan restoration can also be consulted through the Santa Cruz Chapter of the California Native Plant Society or the local Resource Conservation District of Santa Cruz County.
3. Maintain Erosion Control Improvements on firebreaks and roads All waterbars, rolling dips, inside ditches, culverts, etc. should be inspected prior to rain to ensure they are functioning properly and repaired if necessary.
14 This report provides a broad range of suggested recommendations, some of which may be beyond the economic and logistic scope of landowners, (either individually or collectively). 15 RAWS sites http://raws.wrh.noaa.gov/cgi-bin/roman/meso_base.cgi?stn=BNDC1&time=GMT or http://www.raws.dri.edu/cgi-bin/rawMAIN.pl?caCBNL 16 Website is http://www.fema.gov/plan/prepare/evacuation.shtm 17 http://www.well.com/user/dmsml/eas/mont_plan_2003.pdf 18 http://www.wildfirezone.org/assets/images/resource_docs/homeownerserosionhandbook10-07final.pdf 19 Santa Cruz County Environmental Planning maintains several lists of consultants available at the website http://www.sccoplanning.com/html/env/consultants.htm 20 A list of Certified Professionals in Erosion control and Sediment is available at the website http://www.cpesc.org/cc-info/cc-dir-list.asp or at the NRCS office in Capitola 21 A current list of RPF’s is available at the CAL FIRE Resource Managment Office in Felton.
4. Public Road Swanton Road should be evaluated by Santa Cruz County Public Works to determine necessary upgrades to critical bridges and culverts. Swanton Road watercourse crossings should be maintained frequently to keep this single evacuation route for the community open.
5. Private Dams The owners of Boyer Creek Dam and Molino Creek Dam should contact the State Division of Safety of Dams (DSOD) for guidance and have the dams evaluated for safety prior to the winter season.
6. Hazard tree monitoring and removal Fire weakened trees are at risk of falling on residential structures and other infrastructure within the fire area. Trees should be evaluated by a RPF or Certified Arborist to determine if trees should be removed. A Notice of Emergency Timber Operations Exemption or Fire Hazard Exemption should be prepared for submittal to CAL FIRE for areas where commercial trees will be removed. It is recommended that a Licensed Timber Operator be employed for the removal of hazard trees.
7. Trespass prevention (gates, signage, closures) Landowners within the fire area are encouraged to coordinate to maintain and install additional gates to prevent trespass. Signs should be posted on closed roads and trails. A sample “No Trespassing” sign is attached to this report.
8. Watercourses and Fisheries To control sediment delivery to watercourses, erosion control measures on disturbed and burned slopes draining into watercourses should be evaluated for practices utilizing straw wattles, rice straw or weed-free straw, biodegradable erosion control matting or mulching with slash. To maintain fisheries resources, trees within 50 feet of a stream should be retained for large woody debris recruitment. Some woody debris may need to be removed from the lower parts of watersheds to minimize the risk of flooding and debris jams at bridges and culverts. Site specific assessments and work plans should be developed. California Department of Fish and Game (DFG) should be consulted to ensure compliance with DFG regulations.
9. Revegetation Guidelines • Limit seeding to only areas recommended by a certified erosion control specialist; large scale seeding may have negative consequences. • In the limited areas where seed is applied, use only species that will not persist and increase future fire hazard or reduce native vegetation recovery. • Use weed-free mulch only where recommended by certified erosion control specialists • Control erosion and weed spread along fire access roads and fuels breaks.
10. Invasive Non-native plants • Monitor burn areas for invasion, especially of the pernicious jubata grass, which can pose a long term fuels hazard; catching this species early greatly reduces long term control costs
Page 32 • Where possible, control thistles and other weeds to prevent proliferation that can interfere with vegetation recovery • Herbicides should not be applied to control non-native invasive weeds and plants until soils area adequately protected. Large scale use of herbicides requires a permit from the local Agricultural Commissioner’s Office.
11. Fire Prevention Coordination (shaded fuel breaks, road maintenance, road signage and maps, water storage, defensible space, landscape maintenance) • Shaded fuel breaks should be used in areas where access, topography and vegetation are favorable. The Warrenella Truck Trails is a great example of a shaded fuel break that was utilized as a control line along with ground and air suppression resources to contain the fire. CAL FIRE is available to consult with landowners about other strategic locations for shaded fuel breaks. • Existing roads should be maintained on a periodic basis for erosion control and to ensure access during an emergency event. • A system of road signage and mapping is needed across the ownerships within the Lockheed Fire. CAL FIRE can assist through maintaining the GIS database for fire roads and maps. • Additional water storage locations should be considered that are available and accessible to fire engines. • All residents should maintain at least 100 feet of defensible space around their structures. Consult the CAL FIRE website and the Resource Conservation District of Santa Cruz County to obtain defensible space literature and recommendations. • Participate in the Community Wildfire Protection Plan for San Mateo and Santa Cruz Counties to include needed projects across the landscape. High priority projects will be chosen for grant applications and potential financial assistance. Pre-fire projects should consider the design of a chaparral reserve network to maintain connectivity, reduce edge effects, minimize weed invasion and maintain large areas of habitat where fire may take place (Maina and Howe 2000).
Recommendations to Mitigate Potential Soil Erosion and the Impacts of Storm Water Runoff/Flooding
1. Keep it under cover. Protect existing plant cover and establish vegetative cover on all bare or disturbed soil and slopes around property improvements, including home, outbuildings, driveways, etc. before the winter rains. Native and short term non- reseeding, non-invasive plant materials and different types of mulches can be used to protect soil and slopes from the impact of falling rain and storm water runoff. Wide spread seeding and/or planting outside immediate area of home and property improvements is not recommended unless a site specific evaluation and recommendation has been made by a local native plant expert and/or certified erosion control specialist. Consult with the USDA Natural Resources Conservation Service, Resource Conservation District, and Santa Cruz Chapter of the California Native Plant Society or local native plant specialist for re-vegetation determination, guidelines and assistance.
Page 33 2. Do not disturb soil and slopes during the rainy season. Slopes and soil are more susceptible to instability and erosion when vegetation is removed or disturbed and when soil becomes saturated.
3. Drainage, drainage, drainage. Drainage facilities and/or potential runoff impacts on private roadways, long driveways and even fire breaks, especially in fire damaged areas, need to be evaluated. Runoff control treatments including protective release points may be needed to protect down slope areas from erosion, slope failure and flood hazards. Use the following 4-D formula when dealing with drainage and runoff issues.
a. Decrease volumes and/or velocity of runoff by providing velocity dissipation (rock or other prepared outlets) at culvert and drain outlets and breaking up large volumes of runoff coming from roof tops and landscape into smaller less erosive forms. b. Detain runoff and meter over time or store for later use to lessen impact on saturated soil and slopes during peak storm events. Refer to the Resource Conservation District of Santa Cruz County’s “Homeowner’s Guide to Greening of Stormwater Runoff” for ways to detain and/or recycle runoff on your property and around the home. (www.rcdsantacruz.org) c. Dissipate runoff where ever concentrated flows come in contact with bare soil and/or steep slopes by installing practices (slash, rock rip rap, concrete aprons, etc.) that spread runoff and help reduce both the erosive capacity of the water and runoff volumes. Install velocity dissipaters at all culvert and drain outlets to prevent soil erosion. d. Divert runoff if all else fails. Use this “D” with extreme caution. It may be helpful to re-route runoff and drainage away from unstable slopes, eroded areas, unprotected soil, etc. Never divert drainage without a plan or design prepared by licensed or certified professional. Diverting runoff without proper design and/or installation can cause new problems and potential liability, especially if diverted drainage causes damages to neighboring properties.
4. Monitor and maintain all existing and planned runoff, erosion and sediment control measures (including vegetative cover) before and throughout the rainy season. Correct deficiencies as soon as possible. In some areas, leaf litter may be a serious problem for roof, driveway, private road and landscape drainage systems because of all the fire and heat damage done to evergreen vegetation this year. Properly designed and installed trash racks, debris barriers, gutter guards and other similar devices will help to reduce maintenance and allow home and property drainage systems to function properly.
5. Monitoring of creeks and waterways is advisable to make sure that obstructions in streams and waterways do not form and cause flooding, erosion and/or impact downstream road drainage facilities. Refer to the Santa Cruz County Stream Care Guide for further information and details on stream maintenance.
6. Place cross-drains (water bars or rolling dips) on any existing or planned fire/fuel breaks/access road to direct water alternately to both sides of the fire break/road
where needed. Water-bars are usually not needed on ridges of convex slopes that naturally spread runoff water as long as the fire break/road is not entrenched. If fire break/road is entrenched simply remove outside berm/curb allowing water to naturally sheet off the fire break or road. Contact CAL FIRE for assistance with the installation, repair and/or to re-construct any improperly installed fire break/access road water bars that were installed by fire crews, especially ones that may cause erosion problems. Monitor and maintain fire/fuel breaks/access roads throughout the winter and repair defects in drainage and soil protection measures as necessary.
7. Maintain inlets and outlets of culverts, water bars, rolling dips and any other cross- drain used on property access roads. Use slash from pruning as an energy dissipater at cross drain outlets and/or direct into existing tree trunks. Maintain out- sloped orientation. Remove outside berm/curb where necessary to insure that runoff crosses the road in sheet flow and does not get diverted by outside berms and cause erosion. Some road way portions may benefit from rocking where necessary (wet areas, steep road grades, etc.) to prevent erosion and provide winter access. Other roads, particularly roads put to bed for winter may benefit from seeding and/or mulching depending on site conditions. Contact NRCS before doing any grass seeding. Also refer to Private Roads Maintenance Guide for Santa Cruz County for details and further information. The Guide is available on line at the RCD of Santa Cruz County web site: www.rcdsantacruz.org
8. Use emergency/temporary practices such as sand bags, brush & slash, plastic sheeting, and hand dug drainage ditches, etc. with extreme caution or not at all. Do not install without professional guidance. For example: covering slopes with plastic sheeting or dumping brush into gullies or other eroded areas is almost always the wrong thing to do. An improperly designed and/or placed emergency practice, including seeding and seedbed preparation, can be worse than no practice at all. Additionally, emergency measures may cause new hazards or problems, and provide a false sense of security.
9. Prune or remove high hazard fire damaged trees capable of falling on to living structures or roads before winter storms. Don’t remove healthy or slightly damaged trees unnecessarily. Tree root systems are still holding soil and slopes in place and tree cover is protecting soil from impact of falling rain as well as reducing winter runoff. Consult with CAL FIRE and/or a registered professional forester for assistance. Be careful when removing fire damaged trees, especially knob cone pine trees, because they can fall easily without warning. Slash can be applied to bare and disturbed ground in strips across the slope to help protect soil and slopes during the storm season. Slash should be less than knee high to allow new plants to grow through it. This should help minimize erosion and resulting sediment from entering any drainage or waterway. Do not “dump” slash in any drainage (perennial, intermittent or ephemeral drainage) where it could possibly cause a blockage or prevent re-growth of native vegetation. Leaf drop from burned and deciduous trees will also provide additional cover for slopes and soil upslope of stream before winter.
Page 35 10. There is an increased threat of rock fall in some areas because of damage to vegetation and shallow rocky soils and slopes in affected watersheds. Debris barriers are effective in capturing smaller rocks but larger rocks will require more substantial measures. If there is a threat of large rocks releasing from slopes on your property or adjacent properties then seek professional assistance (i.e. a Certified Engineering Geologist or Professional Engineer). Improperly designed and/or placed debris barriers and catchments can do more harm than good.
11. Work with neighboring property owners when determining permanent solutions for drainage and runoff issues. Runoff normally extends beyond property lines. You may be liable for both controlled and uncontrolled releases of collected runoff on to down slope neighboring properties if you decide not to be concerned with potential off site impacts.
12. Be prepared and don’t stay in your home when it becomes unsafe. Have a home and neighborhood evacuation plan. Have an emergency plan for your pets and livestock as well. Stock pile emergency supplies including sandbags, a supply of sand, straw, etc. Pay close attention to weather forecasts, flash flood and storm warnings, water levels in nearby creeks, etc. throughout the winter. Evacuation plans should always include at least one alternative escape route and a list of important/emergency numbers, including numbers of neighboring property owners.
13. Consult with a Certified Engineering Geologist for concerns related to geological issues including potential slope instability and/or occurrence of debris flows.
14. Get professional help from a Certified Professional in Erosion and Sediment Control (CPESC) or other licensed/certified specialist for design and installation assistance with any temporary or permanent practices to control runoff and/or prevent an erosion problem.
15. Close monitoring will determine what other actions may be necessary. Most, if not all, fire damaged areas will regenerate naturally. In addition, there will be a huge leaf drop throughout the fall and winter from trees and shrubs that received heat, smoke and minor-moderate fire damage. These leaves and other plant parts will create natural mulch for fire damaged soils helping to control erosion over the winter months. Furthermore, in areas with ash cover, ash has been shown to reduce both runoff and sedimentation by as much as 49% and 67% respectively.
Roadway related problems, flooding, existing gullies and eroded areas, including stream bank erosion are all likely to appear or get worse this first winter following fire. Sediment levels in creeks and waterways are expected to rise, reducing channel capacities and increasing the likelihood of flooding on properties and down stream. If flooding and or mudslides occur and impact road surfaces do not attempt to drive over flowing water or mud.
Some signs of impending danger from debris flows, landslides and severe erosion and/or imminent flooding include: an intense storm event (1 to 2 inches per hour), especially following previous rainfall that caused ground saturation; water flowing over the landscape
Page 36 where it hadn’t appeared in previous winters; leaning or falling trees; tension cracks along the top edge of slopes and along driveways and roads; seeps and/or increased spring activity in slopes; severely disturbed and unprotected slope areas caused by fire fighting effort or from recent activities to remove fire damage trees and/or other slope holding vegetation. If the creek slows or stops, this could be evidence of a debris dam upstream. If the debris jam were to break loose then flooding would occur as well as bank erosion, sediment and debris damage to properties downstream.
Specific Observations (map points are keyed to geologic maps) Houses, watercourse crossings, and other high-value sites within and down slope from the burn area were assessed to evaluate potential risks from near-site debris flow, rock falls, floods, and other geologic hazards that may not be identified in a regional evaluation. At- risk sites, some with multiple homes, identified as having potential risks to lives or property are listed and briefly described below and summarized in a spreadsheet at the end of this report.
Structures (houses, fish hatchery, and educational facilities) and infrastructure (roads, culverts, dams and bridges) near, within, and or downstream of large burned watersheds appear to be in positions where they may be affected by significant in-channel floods, hyperconcentrated floods, debris torrents, and hillslope-initiated debris flows and debris slides. It appears several sites are in positions where sudden hyperconcentrated floods, debris torrents, debris flows, and rock fall pose a significant risk to lives. Because most of these areas are inhabited year-round, we believe these areas constitute an exigency, a sudden crisis involving a high risk to life that requires immediate action. We believe that inaction may and can lead to the loss of life. The magnitude of post-fire damage will be determined by the intensity and duration of storms that impact the area. A brief description of these areas is provided below:
Subsequent to the 1948 fire the area experienced a relatively mild winter. Research indicates that catastrophic damage did not occur the winter following the fire. During the winter of 1955 (seven years later) significant damage occurred after large storms. The risk associated from this fire could cause damage this winter or in any subsequent winter with large storm events for several years.
Map Point: 483 Of particular concern are the 5 houses within the burn area in the Mill Creek drainage (see Geologic Map of Mill Creek Watershed). The site is located on alluvial terrace material near the bottom of an active inner gorge area with steep (nearly vertical) highly fractured rock walls that overlook the development. The walls confine the Mill Creek watershed at this location. Minor rockfall and dry ravel was observed impacting the site during our site visit. Deposits from previous debris flows and torrents that impacted area were observed during our visit. Photographs and anecdotal evidence obtained and viewed during our visit suggest the site is subject to flooding, debris flows, and rock fall during heavy rains. It is anticipated that the effects of the very high, high and moderate burn severity in the headwater areas that drain to the area will increase and magnify the size and intensity of flooding, rock fall, and debris flows as a function of the severity of this winter and spring rains. The unpaved road that accesses the area appears to be drained by rolling dips or minor fords. Most of the slopes above the houses appear to have a moderate burn severity
Page 37 and contain stored colluvium and loose materials behind the remaining trees. This suggests that the road may be impacted by debris flows and flooding and will likely be impassable after a heavy rain. As such, access to the houses within the lower Mill Creek canyon may be cut off, making evacuation difficult.
Map Points: 490, 491 and 492 The Big Creek Fish Hatchery and 2 rental cabins are located within the burn area in the Big Creek drainage (see Geologic Map of Big Creek Watershed). The site is located on alluvial terrace material near the bottom of an active inner gorge area with steep (nearly vertical) highly fractured rock walls that overlook the development. The walls confine the Big Creek watershed at this location. Minor rockfall and dry ravel was observed impacting the site during our site visit. The fish hatchery and 2 rental units are accessed by a railcar bridge that only has about 4 feet of freeboard above a mostly boulder and cobble channel bar. Additionally, at the mouth of the canyon some of the 7 homes on the floodplains of Big Creek drainage are close to the Big Creek channel. Access to these locations is along private Big Creek Road across a railcar bridge that was replaced in 1998 to provide greater freeboard during floods. Impact to the fish hatchery and rural residential community in the Big Creek drainage from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high burn severity watershed appears likely if the watershed experiences a moderate intensity storm. The potential risk to lives and property increases substantially should a catastrophic failure occur in Boyer Creek, an upstream tributary of Big Creek.
Map Point: 487 Swanton Road crosses Big Creek on a 3-span concrete bridge. Large transported boulders from past debris flows are evident in the channel at the bridge site and the portion of the channel between the right (north) abutment and the north pier has 4 to 5 feet of well- vegetated sediment debris, which is reducing the channel capacity at the bridge. It appears that increased flooding, sediment-laden flooding, and possible debris flow or debris torrent activity may occur along Big Creek because or increased runoff rates and sediment bulking from the watershed that mostly burned at a moderate, high and high burn severity. If this occurs, impacts to the bridge appear likely. The potential risk to lives and property increases substantially should a catastrophic failure occur in Boyer Creek, a tributary to Big Creek.
Map Points: 495, 496, 497 and 498 The Yellow House residence, lodge house and railcar bridge are located on alluvium at the mouth of Bettencourt Gulch near its confluence with Scotts Creek (see Geologic Map of Bettencourt Subwatershed). The lodge is on an alluvial terrace near the bottom of an active inner gorge where nearly vertical, highly fractured rock walls confine the watercourse. Minor rockfall and dry ravel was observed impacting the site during our site visit. The unsurfaced Purdy Ranch Road crosses Bettencourt Creek with a railcar bridge that only has about 7 feet of freeboard above a mostly boulder and cobble channel. The Yellow House is located on the Scotts Creek floodplain at the mouth of the canyon near the channel that drains Bettencourt Gulch. Because almost all (99.8%) of the Bettencourt Gulch subwatershed burned at moderate to very high severity, it appears that the Yellow House residence has a high likelihood of being affected by increased flooding, sediment laden flooding, and debris flows resulting from increased runoff should the watershed experience a moderate- to high-intensity storm during the next few years. It
Page 38 appears that the potential risks to lives and property are high, particularly during periods of intense or prolonged rainfall. Downstream from the confluence of Scotts Creek and Bettencourt Gulch, access from Swanton Road is along private Purdy Ranch Road. This road has two railcar bridges and a failing old Humboldt log crossing where the road crosses a minor tributary to Scotts Creek. Any damage to these crossings would impede potential evacuation during a future emergency.
Map Points: 500 and 501 The upper culvert on an unpaved road for Swanton-Pacific Ranch that crosses Archibald Creek and the lower Archibald Creek culvert at Swanton Road (see Geologic Map of Archibald Creek Watershed) have recently been subjected to burial by debris flows with flooding. This debris was deposited onto both the private road and Swanton Road during past storms. These culverts are likely to be buried again from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high severity burned Archibald Creek watershed.
Map Point: 506 32% of the Boyer Creek watershed above the dam was burned from moderate to very high severity. Boyer Creek drains to Big Creek. The reservoir behind the Boyer Creek dam mostly silted-in during 1982 storms, creating a tule-filled marsh. The dam is currently drained by a 60 inch diameter culvert and had about 6 feet of freeboard to the concrete emergency spillway at the time of this inspection. According to Lockheed representative, Fred R. Rust, the dam last overtopped in 1998. The overtopping event eroded the embankment and left the downstream face with an average of 90 to 110 percent slope with the upper 6 feet nearly vertical and the spillway unsupported and overhanging. Chances of filling and overtopping the dam have been substantially increased because of the Lockheed Fire. If a catastrophic dam failure were to occur it would likely impact downstream houses, roads, bridges and the fish hatchery in the Big Creek watershed from flood, sediment concentrated flood or debris torrent. It is not clear if the dam is currently considered jurisdictional size by the State Division of Safety of Dams, but as with all risk sites in this report, it should be evaluated for its safety prior to the winter period.
Map Point: 507 A railcar bridge is located on a rocked access road from Swanton Road and crosses a Class II tributary to the North Fork Little Creek (see Geologic Map of Little Creek Watershed). Several logs on face of right (west) abutment under the bridge are missing post-fire and the slope under bridge appears to have a wedge failure developing in the upper third of the bridge supporting soils. The Swanton Pacific Ranch Resource Manager has been advised to have an engineering geologic evaluation for this bridge.
Map Point: 509 A concrete single span bridge on Swanton Road crosses Little Creek where large boulders that were transported by past debris flows are present in the channel at the bridge site. An alder-covered bank slump upstream adjacent to the left abutment (when looking down stream) of the bridge directs stream flow into the concrete wing wall on the right abutment. Impact to the bridge from increased flooding, sediment laden flooding, and debris flows and upstream bank slumping resulting from increased runoff from the mostly moderate and high burn severity watershed appears likely.
Page 39 Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Archibald Creek Watershed
Tsc
500 N 501 Scale 1:20,000 Nad 27, California Teale Albers Qal 0 0.2 0.4
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Streams Roads Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090909
Page 40 qd
Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Bettencourt Creek Subwatershed Tsm
N Tsc Scale 1:20,000 Nad 27, California Teale Albers 0 0.2 0.4 495 Qal
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Streams Roads Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090908
Page 41 Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Big Creek Watershed N qd Scale 1:54,000 Nad 27, California Teale Albers 0 0.5 1
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID 488 Tsm Streams Roads Watershed Boundary 490 Tsc Geologic Unit* 491 Qal 492 Qal Qbs Qcl 487 Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090908
Page 42 Tsm
Tsc
Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives CreekBoyer Subwatershed N qd Scale 1:21,000 Nad 27, California Teale Albers 0 0.2 0.4
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Lockheed_streams Roads Tsm Watershed Boundary Tsc Geologic Unit* Tsc Qal Qbs Qcl 506 Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090909
Page 43 qd
507 Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Little Creek Watershed 508 N sch Tsc Scale 1:30,000 Nad 27, California Teale Albers
0 0.3 0.6 Tsm
Miles 509Qal Lockheed Fire Perimeter ! Value at Risk w/ID Streams Roads Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090914
Page 44 Tsc
487
509
Tsc Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives ScottsLower Creek Watershed N 499 501 Scale 1:25,000 Nad 27, California Teale Albers
0 0.25 0.5 qd Qal
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Lockheed_streams Roads Watershed Boundary
Geologic Unit* Qcl 502 Qal Qbs Qcl Qbs Qcl Qcu Pacific Ocean Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090908
Page 45 qd
Qal
505
Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Mill Creek Watershed N Tsm Scale 1:32,000 Nad 27, California Teale Albers
0 0.3 0.6 qd
Miles Tsc Lockheed Fire Perimeter ! Value at Risk w/ID Lockheed_streams Roads Watershed Boundary 483 Geologic Unit* Qal Qbs Qcl Qcu Qal Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090908
Page 46 qd
Tsm
Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Molino Creek Watershed N Tsc Scale 1:30,000 Nad 27, California Teale Albers
0 0.3 0.6
Miles Qcu Qcu Lockheed Fire Perimeter ! Value at Risk w/ID 484 Lockheed_streams Qcl 486 Qbs Qal Roads Qcu Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd sch * Refer to Description Pacific Ocean of Geologic Units Map created by: J. Martinez - 20090924
Page 47 Tsc Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Queseria Creek Watershed Qcu N Qal Scale 1:20,000 502 Nad 27, California Teale Albers Qcu 0 0.15 0.3
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Streams Roads Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd P a c i f i c sch O c e a n * Refer to Description of Geologic Units Map created by: J. Martinez - 20090909
Page 48 qd
Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Upper Scotts Creek Watershed
qd N Tsm Scale 1:46,000 Nad 27, California Teale Albers Tsc 0 0.375 0.75 494
Miles
Lockheed Fire Perimeter 495 ! Value at Risk w/ID Streams 496 Roads 497 Watershed Boundary Geologic Unit* Qal Qal Qbs Qcl 498 Qcu 493 Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090909
Page 49 Lockheed Incident Lockheed FirePost Risk Assessment Geology - Risk to Lives Winter Creek Watershed
N Tsc Scale 1:14,000 Nad 27, California Teale Albers 499
0 0.15 0.3 Qal
Miles
Lockheed Fire Perimeter ! Value at Risk w/ID Lockheed_streams Roads Watershed Boundary Geologic Unit* Qal Qbs Qcl Qcu Tsc Tsm m qd sch * Refer to Description of Geologic Units Map created by: J. Martinez - 20090910
Page 50 References
Alexander, J. M., and C. M. D'Antonio. 2003. Seed bank dynamics of French broom in coastal California grasslands: Effects of stand age and prescribed burning on control and restoration. Restoration Ecology 11:185-197. Andrews, P.L., C.D. Bevins, R.C. Seli. 2008 BehavePlus fire modeling system Users’s Guide, USDA Forest Service General Technical Report RMRS-GTR-106WWW Bartolome, J. W., J. S. Fehmi, R. D. Jackson, and B. Allen-Diaz. 2004. Response of a native perennial grass stand to disturbance in California's Coast Range Grassland. Restoration Ecology 12:279-289. Bean, L. J., and H. W. Lawton. 1993. Some explanations for the rise of cultural complexity in native California with comments on proto-agriculture and agriculture. Pages 27- 54 in T. C. Blackburn and K. Anderson, editors. Before the wilderness. Ballena Press Publication, Menlo Park, California, USA. Brabb, E.E., 1997, Geologic Map of Santa Cruz County, California: A Digital Database, U.S. Geological Survey Open File Report OFR-97-489, posted web page at http://pubs.usgs.gov/of/1997/of97-489/, map scale 1:62,500. Bowman, R.H., and Estrada, D.C., 1980, Soil Survey of Santa Cruz County, California, U.S. Department of Agriculture, Soil Conservation Service, posted web page at http://www.ca.nrcs.usda.gov/mlra02/stcruz.html , 150 p., 10 plates, map scale 1:24,000. Callaway, R. M., and F. W. Davis. 1993. Vegetation dynamics, fire, and the physical environment in coastal central California. Ecology 74:1567-1578. Clark, D. L., and M. V. Wilson. 2001. Fire, mowing, and hand-removal of woody species in restoring a native wetland prairie in the Willamette Valley of Oregon. Wetlands 21:135-144. Clark, J.C., 1981, Stratigraphy, Paleontology and Geology of the Central Santa Cruz Mountains, California Coast Ranges: U.S. Geological Survey, Professional Paper 1168, 51 pages, map scale 1:24,000. Cooper-Clark and Associates, 1975, Preliminary Map of Landslides deposits in Davenport 7.5' Quadrangle, California, Maps prepared for the Seismic and Safety Element of the Santa Cruz County General Plan: Santa Cruz County Planning Department, scale 1:24,000. D'Antonio, C. M., S. J. Bainbridge, C. Kennedy, J. W. Bartolome, and S. Reynolds. 2004. Ecology and restoration of California grasslands with special emphasis on the influence of fire and grazing on native grassland species. white paper Department of Integrative Biology, Berkeley. D'Antonio, C. M., and P. M. Vitousek. 1992. Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annu. Rev. Ecol. Syst. 23:63-87. Debano, L. F., and C. E. Conrad. 1978. The effect of fire on nutrients in a chapparal ecosystem. Pages 489-497 in Ecology. Donato, D. C., J. B. Fontaine, J. L. Campbell, W. D. Robinson, J. B. Kauffman, and B. E. Law. 2009. Conifer regeneration in stand-replacement portions of a large mixed- severity wildfire in the Klamath-Siskiyou Mountains. Canadian Journal Of Forest Research 39:823-838. Dunn, P. H., and L. F. DeBano. 1977. Fire's effect on biological and chemical properties of chaparral soils. Pages 75-84 in Sympsoium on Environmental Consequences of
Page 51 Fire and Fuel Managment in Mediterranean Ecosystems, Palo Alto, CA, Aug. 1-5, 1977. Dyer, A. R., H. C. Fossum, and J. W. Menke. 1996. Emergence and survival of Nassella pulchra in a California grassland. Madroño 43:316-333. Finney, M. A., and R. E. Martin. 1993. Modeling Effects Of Prescribed Fire On Young- Growth Coast Redwood Trees. Canadian Journal Of Forest Research 23:1125- 1135. Florence, M. 1986. Plant succession on prescribed burn sites at Pinnacles National Monument. Pages 31-33 in Fremontia. Fossum, H. C. 1990. Effects of prescribed fire burning and grazing on Stipa pulchra (Hitchc.) seedling emergence and survival. Master's Thesis. University of California at Davis, Davis, California. Fritz, E. 1931. The role of fire in the redwood region. Journal of Forestry 29:939-950. Greenlee, J. M. 1990. Historic Fire Regimes And Their Relation To Vegetation Patterns In The Monterey Bay Area Of California USA. American Midland Naturalist 124:239- 253. Harrison, S., B. D. Inouye, and H. D. Safford. 2003. Ecological heterogeneity in the effects of grazing and fire on grassland diversity. Conservation Biology 17:837-845. Hatch, D. A., J. W. Bartolome, J. S. Fehmi, and D. S. Hillyard. 1999. Effects of burning and grazing on a coastal California grassland. Restoration Ecology 7:376-381. Howe, H. F. 1994. Response of early- and late-flowering plants to fire season in experimental prairies. Pages 121-133 in Ecological Applications. Hughes, F., and P. M. Vitousek. 1993. Barriers to shrub reestablishment following fire in the seasonal submontane zone of Hawai'i. Oecologia 93:557-563. Hunter, J. C., V. T. Parker, and M. G. Barbour. 1999. Understory light and gap dynamics in an old-growth forested watershed in coastal California. Madroño 46:1-6. Jutila, H., and J. B. Grace. 2002. Effects of disturbance on germination and seedling establishment in a coastal prairie grassland: a test of the competitive release hypothesis. Journal of Ecology 90:291-302. Keeley, J. E., and C. J. Fotheringham. 1997. Role of trace gas emissions in smoke- induced germination of a postfire annual. Pages 121 in Bulletin of the Ecological Society of America. Keeley, J. E., and S. C. Keeley. 1981. Post-Fire Regeneration Of Southern-California Chaparral. American Journal Of Botany 68:524-530. Keith, D. A. 1997. Combined effects of heat shock, smoke and darkness on germination of Epacris stuartii Stapf., an endangered fire-prone Australian shrub. Pages 340-344 in Oecologia. LeFer, D., and V. T. Parker. 2005. Effect of seasonality of burn on seed germination in chaparral; the role of soil moisture. Madroño 52:166-174. Maina, G. G., and H. F. Howe. 2000. Inherent rarity in community restoration. Pages 1335- 1340 in Conservation Biology. Margaris, N. S. 1981. Adaptive strategies in plants dominating mediterranean-type ecosystems. Pages 309-315 in F. di Castri, D. Goodall, and R. Specht, editors. Ecosystems of the World 11: Mediterranean-Type Shrublands. Elsevier Scientific Publishing Company, Amsterdam. McDonald. 2009. Tan Oak (Lithocarpus densiflorus). Pages 1-6 in F. T. Bonner and R. G. Nisley, editors. Woody Plant Seed Manual. US Forest Service, Washington, D.C. Meyer, M. D., and P. M. Schiffman. 1999. Fire season and mulch reduction in a California grassland: a comparison of restoration strategies. Madroño 46:25-37.
Page 52 Namkoong, G., and J. H. Roberds. 1974. Extinction Probabilities And The Changing Age Structure Of Redwood Forests. American Naturalist 108:355-368. Odion, D., and Claudia Tyler. 2002. Are long fire-free periods needed to maintain the endangered, fire-recruiting shrub Arctostaphylos morroensis (Ericaceae)? Conservation Ecology 6:4 (online). Odion, D. C. 1995. Effects of variation in soil heating during fire on patterns of plant establishment and regrowth in maritime chaparral. in. Ph.d. Dissertation, University of California Santa Barbara. Peltzer, D. A., M. L. Bast, S. D. Wilson, and A. K. Gerry. 2000. Plant diversity and tree responses following contrasting disturbances in boreal forest. Forest Ecology and Management 127:191-203. Roche, S., J. M. Koch, and K. W. Dixon. 1997. Smoke enhanced seed germination for mine rehabilitation in the southwest of western Australia. Pages 191-203 in Restoration Biology. Russell, W. H., and J. R. McBride. 2003. Landscape scale vegetation-type conversion and fire hazard in the San Francisco bay area open spaces. Landscape and Urban Planning 64:201. Seabloom, E. W., E. T. Borer, V. L. Boucher, R. S. Burton, K. L. Cottingham, L. Goldwasser, W. K. Gram, B. E. Kendall, and F. Micheli. 2003. Competition, seed limitation, disturbance, and reestablishment of California native annual forbs. Ecological Applications 13:575-592. Shatford, J. P. A., D. E. Hibbs, and K. J. Puettmann. 2007. Conifer Regeneration after Forest Fire in the Klamath-Siskiyous: How Much, How Soon? Journal of Forestry 105:139. Stephens, S. L., and D. L. Fry. 2005. Fire History in Coast Redwood Stands in the Northeastern Santa Cruz Mountains, California. Fire Ecology 1:2-19. Suzuki, N., and J. P. Hayes. 2003. Effects of thinning on small mammals in Oregon coastal forests. Journal of Wildlife Management 67:352-371. Tyler, C. M. 1996. Relative importance of factors contributing to postfire seedling establishment in maritime chaparral. Pages 2182-2195 in Ecology. Ucitel, D., D. P. Christian, and J. M. Graham. 2003. Vole use of coarse woody debris and implications for habitat and fuel management. Journal of Wildlife Management 67:65-72. Van Dyke, E., and K. D. Holl. 2001. Maritime chaparral community transition in the absence of fire. Madroño 48:221-229. Vogl, R. J. 1973. Ecology of Knobcone Pine in the Santa Ana Mountains, California. Ecological Monographs 43:125-143. Williams, C. E. 1989. Population Ecology of Pinus Pungens in Pine-Oak Forests of Southwestern Virginia. Virginia Tech. Zedler, P. H., and G. A. Scheid. 1988. Invasion of Carpobrotus edulis and Salix lasiolepis after fire in a coastal chaparral site in Santa Barbara County, California. Pages 196- 201 in Madroño. Zenner, E. K. 2005. Development of tree size distributions in Douglas-fir forests under differing disturbance regimes. Ecological Applications 15:701-714.
Page 53 POST FIRE RESTORATION “Dos” and “Don’ts”
“ DO’S”
DO Consult with the Natural Resources Conservation Service (NRCS) and Resource Conservation District (RCD) of Santa Cruz County and/or a private land restoration consultant before starting any landscape, slope or soil restoration effort on areas damage by wild fire. Note: Request a fire damage assessment from NRCS/RCD before starting your land and natural resource restoration project. Contact us at:
The NRCS/RCD office is located at: 820 Bay Ave., Suite 128, Capitola, CA 95010 831-475-1967 (NRCS); 464-2950 (RCD) RCD website: www.rcdsantacruz.org
Note: NRCS is a non-regulatory federal agency under the U. S. Department of Agriculture whose mission is to “Help People Help the Land”. The agency was formed nearly 75 years ago with the help of landowners. All services are provided, free of charge, through a mutual agreement with the RCD of Santa Cruz County. Additionally, all information provided or resource data collected on private properties by NRCS is kept confidential and only shared with the property owner or legal agent unless NRCS has written permission, by the property owner, to release the information to others.
DO Gather as much information as possible from CAL FIRE, local fire district officials, Fire Safe Council, NRCS, the RCD of Santa Cruz County, and/or local fire restoration consultants, and plant experts regarding reducing fire hazard and making your property fire safe when planning your property restoration.
DO Evaluate and map out locations of existing and/or pre-fire subsurface drainage, irrigation and utility facilities on your property including: under ground pipe drains and outlets; roof runoff/gutter drain outlets; culverts; irrigation systems; utilities, etc. Determine if still operable and/or degree of damage, if any. Note: Many underground plastic drains and irrigation lines may have melted or otherwise been destroyed in the fire or by the fire fighting effort.
DO Install sediment control measures, such as straw wattles, mulching, plantings, slash, sediment traps and/or other properly designed and located sediment control measures, if necessary, and as directed by NRCS, RCD or a Certified Professional in Erosion and Sediment Control (CPESC). Note: Sediment control measures will help to prevent eroded and displaced soil from entering streams, roadside ditches and waterways, and help protect water quality and water supplies. Consult with licensed landscape contractors or other licensed contractors with erosion and sediment control experience for design and installation assistance. If straw mulch is used is should be rice straw or weed free.
DO Control invasive non-native plants that will try to colonize some soils within the fire area. Note: Do not apply herbicides to control non-native invasive weeds and plants on forest lands until soils are adequately protected. Large scale use of herbicides will require a permit from the local Agricultural Commissioner’s office.
Page 54
DO Coordinate restoration efforts with neighbors and/or road & homeowner associations.
DO Re-plant damaged landscapes with drought tolerant, fire retardant native plants with re-sprouting ability. Use planting stock and/or seed that are native to the area and is from a locally collected source. Consult with NRCS/RCD for a list of plants to consider. Note: Wide spread seeding and/or planting outside immediate area of home and property improvements is not recommended unless a site specific evaluation and recommendation has been made by a local native plant and/or certified erosion control specialist. Consult with the USDA Natural Resources Conservation Service, Resource Conservation District, Santa Cruz Chapter of the California Native Plant Society or local native plant specialist for re-vegetation determination, guidelines and assistance.
DO Obtain any necessary permits before cutting down trees, performing any major land grading activity, building any retaining wall, constructing a permanent sediment or erosion control structure, or doing any work in a riparian area, wetland, stream course or other natural area. Note: Permits and/or consultations may be needed from the County of Santa Cruz, California Dept of Fish and Game, U.S. Fish & Wildlife Service, California Regional Water Quality Control Board, U.S. Army Corp of Engineers, and NOAA/National Marine Fisheries Service.
DO Monitor and maintain fire and fuel breaks that may have been created by fire fighters on your property. Water bars/breaks should be provided and maintained on these fire control measures so that runoff water does not concentrate and cause erosion. Consult with CAL FIRE (831-335-5353) regarding maintenance assistance of fire and fuel breaks constructed by fire fighters on your property.
DO Monitor and maintain all existing and planned erosion, sediment, and drainage control measures, including vegetative treatments, before during and after all future rainfall events. Correct deficiencies as soon as possible. Note: One of the main reasons why recommended treatment practices fail following installation is the lack of long term maintenance by the landowner or responsible party.
DO Hire and/or consult with licensed contractors, preferably ones that are certified and experience in soil erosion and sediment control and/or native landscape restoration, for design and installation assistance of vegetative and/or structural measures needed to restore slopes, soils, proper drainage conditions, landscape and native plant community.
Page 55 DON’TS:
DON’T Be too quick to remove fire damaged vegetation, including trees that were not completely burned. Many of the damaged and scorched native plants will re-sprout and come back, including redwoods, and oak trees that were severely burned. Note: Consider pruning first before removing the entire plant. Be careful when removing fire damaged trees, especially knob cone pine trees, because they can fall easily without warning Consult with a registered professional forester, certified arborist and/or NRCS for further advice.
DON’T Place loose debris, pruning’s, discarded fire-damaged vegetation in gullies, drainage swales or watercourses, over stream banks, etc. in an attempt to protect bare soil without first consulting with NRCS. Piles of brush will prevent plants from re-establishing under dense brush piles and may dislodge if in contact with concentrated runoff or stream flows causing other problems. Note: Removed brush can sometimes be used as mulch if chipped or spread thinly over the critical soil areas.
DON’T Plant the Santa Cruz County Erosion Control Seed Mix. This mix is a non-native mix of grasses and one legume that was not intended for wild land or fire damaged soil/slope restoration. Don’t plant this mix or other non-native, invasive plants or re-seeding grasses, such as annual ryegrass, blando brome, etc. Wide spread seeding and/or planting outside immediate area of home and property improvements is not recommended unless a site specific evaluation and recommendation has been made by a local native plant and/or certified erosion control specialist. Consult with the Natural Resources Conservation Service, Resource Conservation District, Santa Cruz Chapter of the California Native Plant Society or local native plant specialist for re-vegetation determination, guidelines and assistance.
Note: In some situations bare and disturbed soil and slopes can be re-seeded/re-planted with native grasses and plants but only if the seed and plant materials are from local known sources and indigenous to the area that needs treatment. Other native grasses and plants may discourage local natives from re-establishing on their own, and/or compete with, and/or slow down native re-establishment. If white ash is present, then resident seed from pre-existing native plants may no longer exist. White ash is an indicator that the fire burned very hot. Resident seed bank in the soil may have been compromised from the fire in high intensity burn areas. Re-seeding these areas to native grasses and/or re-planting with native plants of the same genotype, according to a re-vegetation plan developed by an experienced fire ecologist/native plant specialist, might be a good idea, especially if the area is near a home or other property improvements.
DON’T Use materials such as broken asphalt or concrete, inorganic debris or other objects as an emergency or permanent erosion control measure, especially if these materials can come in contact with runoff water, natural drainages and stream courses. Note: In some cases, rock and broken concrete can be used as velocity dissipaters and placed at the outlets of road culverts or other drains to protect the soil from erosion and washout, provided these dissipaters are designed by an appropriate professional.
DON’T Cover fire damaged slopes with plastic sheeting in an attempt to prevent slope failure and protect bare or disturbed soil from next year’s rainfall. Plastic sheeting will:
Page 56 increase runoff and the likelihood of erosion; retain moisture in the ground increasing the possibility of slope saturation and instability; and kills root systems of native plants trying to re-establish naturally. Plastic sheeting is almost always the wrong thing to do. Note: Depending on site conditions, an alternative to plastic sheeting might be the use of hydro- mulch, a proper application of rice straw, or an erosion control blanket if recommended by a Certified Professional Erosion and Sediment Control (CPESC), fire restoration specialist or geo-technical consultant.
DON’T Control and concentrate future property drainage and runoff without a proper drainage control design that considers proper drainage facility sizing, location and dispersal method. When ever possible keep surface runoff in natural “sheet” flow and incorporate practices such as vegetative cover to slow runoff and improve the water infiltration capacity of the soil. Note: Consult with NRCS for general planning information on controlling drainage around your home and property before proceeding with drainage repairs and improvements following fire damage. For design and installation assistance contact a landscape contractor experienced in erosion and drainage control.
DON’T Use straw bales (in whole bale form) as water diversion and detention devices or for sediment control in burn areas. Contrary to popular belief and use these devices require a great deal of maintenance and are not right for most situations. Their design, location, and installation should only be done by a qualified contractor certified in erosion and sediment control. Straw wattles and loose straw that is simply spread over bare and disturbed soil is much more effective in protecting soil than keeping it in bale form. Note: Rice or weed-free straw should only be used to prevent the possibility of non-native grasses and weeds, contained in straw bales, from colonizing treatment areas.
DON’T Disturb the hydrophobic soil layer that forms on some soils following fire on slopes susceptible to land sliding. Hydrophobicity is a natural phenomenon that actually gives the soil a water repellant ability that reduces infiltration and the capacity of the soil to hold water. The hydrophobic layer is normally found within 6 inches of the surface. In other areas, it may be advisable to break up this layer to aid in plant establishment and water infiltration lessening the impacts of runoff and erosion. For more information on soil hydrophobicity and/or an on-site soil evaluation & site assessment contact NRCS.
DON’T Disturb potentially unstable slopes, especially those in fault areas and/or with signs of previous movement or known historic instability. Disturbances such as grading, cutting, removing trees root wads or other deep excavations will increase the likelihood of future slope failure. Note: If these slope alternations are absolutely necessary, then consult with a registered geologist or geo-technical expert before slope disturbance/restoration activity.
DON’T Do anything. This may be the best solution on some properties. Doing nothing will allow nature and time to heal soil and vegetation damage naturally, especially in wild land and other natural areas. In fact, tampering with natural processes may very well delay natural recovery and re-establishment of pre-existing native cover.
DON’T Do what your neighbor’s doing. Every situation is unique whether or not the neighbor had expert advice or not before installing temporary or permanent land and water protection measures. Your property is different in many regards including soil type, slopes, drainage conditions, type and condition of plant cover, degree of fire damage, etc. Get
Page 57 expert advice and a site damage assessment, including treatment recommendations, from NRCS before proceeding with your property restoration efforts. Note: Practices such as sandbags, plastic, straw bale basins and check dams, etc. are all temporary and require a great deal maintenance. Furthermore, they are not right for every situation and can actually make problems worse or create new ones.
DON’T Wait until the last minute to plan, design and install erosion, sediment or drainage control practices that may be necessary to safeguard your home and property before next winter. Note: The nature and extent of your restoration effort will depend on: degree of damage; time to acquire an appropriate plan & design; securing any necessary permits; lining up a contractor & doing the work.
Page 58 FIRESCAPING and EROSION CONTROL with NATIVE PLANTS
DROUGHT TOLERANT & FIRE RESISTANT SHRUBS
Common Name Scientific Name
Lemonade Berry Rhus integrifolia Coffee Berry Rhamnus californica Rock Rose Helianthemum scoparium California Fuchsia Epilobium canum (Zauschneria californica) Sugar Bush Malosma (Rhus) ovata California Lilac, Blue Blossom Ceanothus thyrsiflorus Golden Yarrow Eriophyllum confertiflorum California Rose Rosa Californica Snowberry Symphoricarpos albus
FIRE RESISTANT TREES (upland)
Coast Live Oak Quercus agrifolia Toyon Heteromeles arbutifolia California Wax Myrtle Myrica californica (may need some water) Catalina Ironwood Lyonothamnus floribundus Yellow Willow Salix lucida Western Redbud Cercis occidentalis Santa Cruz Island Oak Quercus tomentella Tanoak Lithocarpus densiflora
FIRE RESISTANT TREES & SHRUBS (riparian, irrigated or wet areas) Where soil is moist year-round, all vegetation has higher moisture content, making it more fire-resistant than plants growing in dry locations
Coast Redwood Sequoia sempervirens Western Sycamore Platanus racemosa Willow (yellow, red. arroyo, coastal) Salix, spp Big Leaf Maple Acer macrophyllum Blue Elderberry Sambuscus Mexicana Thimbleberry Rubus parviflorus California Hazelnut Corylus cornuta var.californica Creek Dogwood Cornus sericea ssp. occidentalis Flowering Currant Ribes sanguineum var. glutinosum Bush Anemone Carpenteria californica Red or White Alder Alnus rubra (red) Alnus rhombifolia (white)
FIRE RESISTANT NATIVE PERENNIAL FORBS
Yarrow Achilea spp. California Poppy Eschscholzia californica Penstemon Penstemon spp.
Page 59 Blue-Eyed Grass Sysyrinchium bellum. California Buttercup Ranunculus californica Bracken Fern Pteridium aquilinum var.pubescens
FIRE RESISTANT NATIVE GROUNDCOVERS / SHORT GRASSES
Douglas Iris and related spp. Iris douglasiana and other native Iris Alum Root Heuchera, spp. Sword Fern Polystichum munitum Redwood Sorrel Oxalis oregano Dudleyas Dudleya, spp. Pine Grass Calamagrostis rubescens Idaho Fescue Festuca idahoensis Molate Fescue Festuca rubra
Note: All the above plants have soil erosion and protection qualities. Many of the above plants are also drought tolerant but may require some supplemental irrigation during initial establishment.
In general, common characteristics of fire resistant plants are as follows:
1. Low sap or resin content; 2. Grow without accumulating dead branches, needles or leaves; and 3. Easily maintained and pruned; 4. Grow low to the ground 5. Low biomass or low density 6. Large and/or thick leaves with high moisture content that don’t ignite quickly like plants with small leaves such as chamise and junipers.
Note: Space plants so there is horizontal and vertical discontinuity. This will decrease the likelihood of fire spreading to tree canopies and from plant to plant.
INVASIVE AND/OR HIGH FIRE HAZARD SHRUBS AND TREES
Stay clear of the following plants: Acacia; pampas and jubata grasses; juniper; eucalyptus; chamise; all pines, including knob cone and Monterey pine; cypress trees; Douglas-fir; coyote brush; greasewood; sagebrush; upright forms of rosemary; buckwheat; sage; pepper tree; bamboo; palms; periwinkle/vinca; Algerian, English or German ivy; French, Spanish and Scotch broom, hemlock, spruce, cedar, and Douglas-fir.
Regarding other plant choices and fire resistant landscaping ideas Contact: the Natural Resources Conservation Service (831-475-1967) or the RCD of Santa Cruz County (831- 464-2950); www.rcdsantacruz.org.
Page 60
Page 61
Page 62
Page 63 Sample No Trespassing Sign:
NO TRESPASSING
This road system is owned and maintained by: FILL IN LANDOWNERS. Hazardous conditions exist. Any unpermitted use of these roads that damages the road surface, damages drainage structures or causes the landowner to repair the road, by a trespasser, shall be considered malicious damage. Use of this road system without written permission of the landowner shall be deemed trespassing and a violation of the following laws which could result in a citation:
• California Penal Code Section (PC) 602(h)(1) – Trespassing
• PC 594(a) Vandalism
Various sensitive wildlife and plant species exist in this area. Un-authorized vehicle use of these roads could result in illegal disturbances to these species and could also result in enforcement actions.
Page 64 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 483 Reviewer C. Michael Huyette Date 8/31/09 Address 460, 464 and 466 Swanton Road Quad Davenport Watershed/Drainage Mill Creek GPS location 37 05.425 122 13.996 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 2406 ac. c. slope (average and range) 65/ 55-100 d. channel presence , channel grade Observations 1. Percent of watershed burned 68%
2. Geology: Formation or unit name (if available) Tsc lithology: Mudstone/Shale fabric Highly Fractured penetrative structures: yes no, type orientations regolith/soil: texture SM thickness 24 inches other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98% Fan alluvial wash other comments
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other 6. Soil burn severity (Parsons, 2003): high 5% moderate 95%% low % 7. Post fire ground cover: vegetation/litter/leaf fall 20%% surface rock 5%% total cover 25% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer 1 inch post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Page 65 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 484 Reviewer C. Michael Huyette Date 9/1/09 Address Swanton Road east of MP 0.71 Quad Davenport Watershed/Drainage Molino Creek GPS location 37 02.293 122 12.756 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 484a-484c Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Earthfill Dam 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 1040 ac. c. slope (average and range) 70/ 55-110 d. channel presence 8'w, 3'd, channel grade 5% Observations 1. Percent of watershed burned 78%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98% Fan alluvial wash other comments undulating upstream floodplain with boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 5% moderate 95%% low % 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 25%% total cover 25% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other Overtopping 10. Possible Risk to Life: High Moderate Low (to areas downstream from the dam) 11. Possible risk to property: High Moderate Low
Page 66 California Geological Survey Site Number ___484__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Breech or repair dam to avoid catastrophic failure.
Sketch Dam face has been overtopped leaving ±35 foot high near vertical downstream face and 1.5 foot deep x 6 feet wide concrete spillway at left dam abutment shot-gunned about 3 feet beyond the dam face with a ±25 foot drop top the dam toe. The main drain is a 48 inch cmp with a metal gate (open) in a ±6 foot high x ±20 foot wide concrete headwall. The upstream dam face is ±15 feet above the channel or ±10 feet above the alder covered upstream floodplain. The dam is ±1/2 mile upstream of Swanton Road.
Eroded downstream dam face. Upstream dam toe with main outlet pipe.
Page 67 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 486 Reviewer C. Michael Huyette Date 9/1/09 Address Swanton Road MP 0.71 Quad Davenport Watershed/Drainage Molino Creek GPS location 37 02.244 122 13.249 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 486a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 1040 ac. c. slope (average and range) 65/ 55-vertical d. channel presence 8'w,4'd, channel grade 2% Observations 1. Percent of watershed burned 78%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 1997-98 Fan alluvial wash other comments undulating 3-4' high floodplain banks with boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0%% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 25%% total cover 25% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if the crossing is in use and the upstream dam fails) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Channel approaches culvert about 30 feet south of the inlet.
Page 68 California Geological Survey Site Number ___486__ Lockheed Burn Site Evaluation Form Page 2
Description: Concrete lined arch culvert ±6 feet wide x ±7 feet tall with concrete apron floor. Soil cement headwall ±25 feet wide and ±18 feet tall. Channel approaches inlet ±30 feet to the south and has to parallel the headwall to get to the inlet due to ±4 foot high vegetated channel bar along the north bank. Increased Risk if catastrophic dam failure occurs upstream, see Site Number 484.
Upstream concrete lined arch culvert inlet.
Page 69 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 487 Reviewer C. Michael Huyette Date 9/1/09 Address Big Creek Bridge at Swanton Road Quad Davenport Watershed/Drainage Big Creek GPS location 37 04.018 122 13.722 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 487a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 7211 ac. c. slope (average and range) 65/ 50-80% banks d. channel presence 15'w,2'd, channel grade 2% Observations 1. Percent of watershed burned 26%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0%% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 45% total cover 45% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Channel flows under left (south) two spans, the right (north) third of the channel has between 4 and 5 feet of vegetated stream channel sediment between the north pier and north abutment.
Page 70 California Geological Survey Site Number ___487__ Lockheed Burn Site Evaluation Form Page 2
Description: Concrete 3-span bridge with 2 in-stream piers. Generally has 12 feet of clearance from channel to bottom of bridge but the channel between the north pier and north abutment is partially blocked by 4 to 5 feet of stream sediment vegetated with brush and berries. Stream blockage reduces capacity under the bridge and increases scour potential at the piers due to channel constriction. Increased Risk if catastrophic dam failure occurs on Boyer Creek, an upstream tributary to Big Creek, see Site Number 506.
Upstream side of the bridge crossing showing unrestricted south 2/3rds of the channel.
Page 71 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 488 Reviewer C. Michael Huyette Date 9/1/09 Address Big Creek Historic Powerhouse location Quad Davenport Watershed/Drainage Big Creek GPS location 37 04.450 122 13.323 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 488a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other out-bldg 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 7211 ac. c. slope (average and range) 65/ 50-80% d. channel presence 40'w,2'd, channel grade 5- 8% Observations 1. Percent of watershed burned 26%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume minor characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 40% surface rock 20% total cover 60% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other
Page 72 California Geological Survey Site Number ___488__ Lockheed Burn Site Evaluation Form Page 2
Description: Increased Risk if catastrophic dam failure occurs on Boyer Creek, an upstream tributary to Big Creek, see Site Number 506.
Outbuilding
Outbuilding in background next to creek channel.
Page 73 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 490 Reviewer C. Michael Huyette Date 9/1/09 Address 675, 705 and 825 Big Creek Road Quad Davenport Watershed/Drainage Big Creek GPS location 37 04.450 122 13.323 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Fish Hatchery 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 7211 ac. c. slope (average and range) 65/ 50-80% d. channel presence 30'w,4'd, channel grade 5% Observations 1. Percent of watershed burned 26%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume minor characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 10% surface rock 20% total cover 30% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if the upstream dam fails) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Page 74 California Geological Survey Site Number ___490__ Lockheed Burn Site Evaluation Form Page 2
Description: The Big Creek Fish Hatchery and two rental cabins are located within the burn area in the Big Creek drainage (see Geologic Map of Big Creek Watershed). The site is on alluvial terrace materials at the base of steep (nearly vertical) highly fractured debris slide slopes. Minor rockfall and dry ravel from these steep slopes was observed to be impacting the site during our site visit. The fish hatchery and rental units are accessed by a railcar bridge that only has about 4 feet of freeboard above a mostly boulder and cobble channel bar. Increased Risk if catastrophic dam failure occurs on Boyer Creek, an upstream tributary to Big Creek, see Site Number 506.
Page 75 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 491 Reviewer C. Michael Huyette Date 9/1/09 Address Big Creek Road Railcar Bridge Quad Davenport Watershed/Drainage Big Creek GPS location 37 04.353 122 13.412 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 491a - 491f Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 65' Railcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 7211 ac. c. slope (average and range) 65/ 50-80% d. channel presence 50'w, channel grade 5% Observations 1. Percent of watershed burned 26%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume minor characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 10% surface rock 20% total cover 30% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if bridge is in use during major storm) 11. Possible risk to property: High Moderate Low
Page 76 California Geological Survey Site Number ___491__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Description: The site is on alluvial terrace materials near the base of steep (nearly vertical) debris slide slopes that expose highly fractured Santa Cruz Mudstone rock walls. Minor rockfall and dry ravel was observed to be impacting the site during our site visit. The 65 foot long railcar bridge that access the Big Creek Fish Hatchery and two rental cabins is several hundred yards downstream from the structures. The bridge is supported by H piles on pier block in front of old log cribbing at the east abutment, with a concrete supported west abutment. For approximately 75% of the channel width spanned by the bridge the clearance between the base of the railcar and an instream gravel bar is only about 4 feet. Clearance for the remaining 25% of the span is about 8 feet. The restricted freeboard increases the risk of bridge being compromised during high flows, which could isolate the Fish Hatchery and rental cabins. Increased Risk if catastrophic dam failure occurs on Boyer Creek, an upstream tributary to Big Creek, see Site Number 506.
Upstream side of the bridge crossing showing restricted east 75% of the channel.
Page 77 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 492 Reviewer C. Michael Huyette Date 9/1/09 Address 300, 340, 350, 360, 410, 420 and 425 Big Creek Road Quad Davenport Watershed/Drainage Big Creek GPS location 37 04.143 122 13.641 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 492a - 492b Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 65' Railcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 7211 ac. c. slope (average and range) 65/ 50-80% d. channel presence 30'w, channel grade 2% Observations 1. Percent of watershed burned 26%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders to 3' dia fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders to 3' dia. and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 10% surface rock 20% total cover 30% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (If upstream dam fails) 11. Possible risk to property: High Moderate Low
Page 78 California Geological Survey Site Number ___492__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Description: A house, 6 rental cabins and railcar bridge are located immediately downstream of the burn area at the mouth the Big Creek canyon drainage (see Geologic Map of Big Creek Watershed). The house and rental units are accessed the bridge, which only has about 6 to 8 feet of freeboard above a mostly boulder and cobble channel. The existing bridge is a raised replacement from one that failed during the 1997-98 storms and is built over the former bridge site where the old concrete south abutment remains show the old bridge seat with a height about 6 feet above the channel thalwag elevation. High flow events could put at risk lives or isolate the upstream home and rental cabins and the Fish Hatchery and 2 rental units further up the canyon (see Site Number 490). Increased Risk if catastrophic dam failure occurs on Boyer Creek, an upstream tributary to Big Creek, see Site Number 506.
South bridge abutment showing old bridge seat elevation.
Page 79 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 493 Reviewer C. Michael Huyette Date 9/1/09 Address Scotts Creek Bridge on Swanton Road Quad Davenport Watershed/Drainage Upper Scotts Creek GPS location 37 04.794 122 14.823 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 493a - 492c Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 3-span Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 5702 ac. c. slope (average and range) 65/ 50-80% d. channel presence 40'w, channel grade 1 to 2% Observations 1. Percent of watershed burned 20
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders to 8" dia fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream boulders to 3' dia. and cobbles
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 10% surface rock 20% total cover 30% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low
Page 80 California Geological Survey Site Number ___493__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Monitor foundation scour during storm periods. Re-armor base of left abutment to resist scour.
Description: The 3-span bridge is supported by wood piles with concrete caps at the abutments and two pier locations. There is approximately 14 feet of freeboard above a mostly mudstone cobble streambed. Steel beams support the bridge deck between the piers; wooden girders support the bridge deck between the piers and abutments. Cement-sack armor is located near the base of the left abutment where the abutment toe and pier foundation materials may be susceptible to scour during high flow events. The scour potential at the bridge site is increased from the increased runoff flows from the burned portion of the watershed. Without sufficient armor the abutment and piers foundations are prone to loss of support due to scour erosion.
Left bridge abutment and left pier bent showing old concrete sack armor and scoured abutment toe.
Page 81 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 494 Reviewer C. Michael Huyette Date 9/1/09 Address West bank of Scotts Creek north of Bettencourt Gulch Quad Davenport Watershed/Drainage Upper Scotts Creek GPS location 37 06.279 122 15.087 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 494a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2 Rental Cabins 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 5702 ac. c. slope (average and range) 65/ 50-80% d. channel presence 40'w, channel grade 1 to 2% Observations 1. Percent of watershed burned 20
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other Creekbank failure during or after high flows 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Monitor bank scour during storm periods.
Page 82 California Geological Survey Site Number ___494__ Lockheed Burn Site Evaluation Form Page 2
Description: The rental cabins are adjacent to the 10 to 12 foot high near vertical creek bank of Scotts Creek outside of the burn area but downstream from a portion of the Upper Scotts Creek watershed that did burn. The cabins are susceptible to flooding, sediment concentrated flood and the nearby creek bank may fail due to scour erosion during, or immediately following, high storm flow events.
Right bank of Scotts Creek near two rental cabins.
Page 83 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 495 Reviewer C. Michael Huyette Date 9/1/09 Address Yellow House, Lodge House and railcar bridge over Bettencourt Quad Davenport Creek. Watershed/Drainage Bettencourt Creek Subwatershed GPS location 37 06.080 122 15.081 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 495a - 495d Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Lodge Cabin 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 496 ac. c. slope (average and range) 70/ 50-90% d. channel presence 15, channel grade 1 to 2% Observations 1. Percent of watershed burned 99
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Page 84 California Geological Survey Site Number ___495__ Lockheed Burn Site Evaluation Form Page 2
Description: The Yellow House residence, lodge house and railcar bridge are on alluvium at the mouth of Bettencourt Gulch near its confluence with Scotts Creek (see Geologic Map of Bettencourt Subwatershed). The lodge is on an alluvial terrace near the bottom of an active inner gorge where nearly vertical, highly fractured Santa Cruz mudstone rock walls confine the watercourse. Minor rockfall and dry ravel was observed impacting the site during our site visit. The unsurfaced Purdy Ranch Road crosses the creek with a railcar bridge that only has about 7 feet of freeboard above a mostly boulder and cobble channel. The Yellow House is on the Scotts Creek floodplain at the mouth of the canyon near the channel that drains Bettencourt Gulch. Because almost all (99.8%) of the Bettencourt Gulch subwatershed burned at moderate to high burn severity, it appears that the Yellow House has a high likelihood of being affected by increased flooding, sediment laden flooding, and debris flows resulting from increased runoff should the watershed experience a moderate- to high-intensity storm during the next few years. It appears that the potential risks to lives and property are High, particularly during periods of intense or prolonged rainfall. Downstream from the confluence of Scotts Creek and Bettencourt Gulch, access from Swanton Road is along private Purdy Ranch Road. This road has two railcar bridges and a failing old Humboldt log crossing where the road crosses a minor tributary to Scotts Creek. Any damage to these crossings would impede potential evacuation during a future emergency.
Lodge House within the narrow canyon of Bettencourt Gulch.
Page 85 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 496 Reviewer C. Michael Huyette Date 9/1/09 Address Railcar bridge over Scotts Creek downstream of Bettencourt. Quad Davenport Watershed/Drainage Upper Scotts Creek watershed GPS location 37 05.967 122 15.141 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 496a - 496c Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Railcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 5702 ac. c. slope (average and range) 65/ 50-90% d. channel presence 30, channel grade 1% Observations 1. Percent of watershed burned 20% and 99% of Bettencourt Subwatershed
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0%% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (If bridge is in use during storm events) 11. Possible risk to property: High Moderate Low
Page 86 California Geological Survey Site Number ___496__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Description: The 40 foot long railcar bridge is supported by log crib abutments about 10 feet above the channel of Scotts Creek. Scour is evident at the toe of the west abutment. A McCrary family member said the flow in Scotts Creek reached the bottom of the bridge during the 1997-98 winter season. Impact to the bridge site, which is immediately downstream from the confluence of Bettencourt Creek, from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high burn severity watershed appears likely if the watershed experiences a moderate intensity storm.
Log crib supported west abutment showing scour at toe.
Page 87 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 497 Reviewer C. Michael Huyette Date 9/1/09 Address Railcar bridge on Purdy Ranch Road. Quad Davenport Watershed/Drainage Upper Scotts Creek watershed GPS location 37 05.671 122 14.975 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 497a and 497b Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Railcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size <100 ac. c. slope (average and range) 65/ 50-90% d. channel presence 3'w, channel grade 5% Observations 1. Percent of watershed burned 20% and 99% of Bettencourt Subwatershed
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if bridge is in use during storm events) 11. Possible risk to property: High Moderate Low
Page 88 California Geological Survey Site Number ___497__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Description: The 25 foot long railcar bridge on Purdy Ranch Road was installed in 2004 to replace a pulled culvert on a west flowing Class II tributary that drains to nearby Scotts Creek. There is only about 4 feet of clearance from the channel to the bottom of the bridge. The burn area is immediately upslope of the bridge site. Impact to the bridge site, from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high burn severity sub-watershed appears likely if the watershed experiences a moderate intensity storm.
25 foot long railcar bridge at pulled culvert site leaving about 4’ of freeboard.
Page 89 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 498 Reviewer C. Michael Huyette Date 9/1/09 Address Humboldt crossing on Purdy Ranch Road. Quad Davenport Watershed/Drainage Upper Scotts Creek watershed GPS location 37 04.938 122 14.796 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 498a and 498b Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Humboldt Crossing 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size <100 ac. c. slope (average and range) 65/ 50-90% d. channel presence 4'w, channel grade 5-10% Observations 1. Percent of watershed burned 20% and 99% of Bettencourt Subwatershed
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 100% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if crossing is in use during storm events) 11. Possible risk to property: High Moderate Low
Page 90 California Geological Survey Site Number ___498__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evacuate during storm periods prior to road closures.
Sketch The failing Humboldt crossing of Purdy Ranch Road is below the burn area on a side Class III west flowing tributary to Scotts Creek. The opening at the inlet base of the Humboldt is approximately 2 feet high and 4 feet wide. The crossing could be impacted by increased flows and plugging potential from debris torrents due to the moderate to high severity burn in the upstream canyon.
Humboldt Class III watercourse crossing on Purdy Ranch Road.
Page 91 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 499 Reviewer C. Michael Huyette Date 9/1/09 Address Swanton Road MP 2.36. Quad Davenport Watershed/Drainage Winter Creek watershed GPS location 37 04.667 122 14.602 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 499a and 499b Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 141 ac. c. slope (average and range) 20/ 10-40% d. channel presence 10'w 6'd, channel grade 2-5% Observations 1. Percent of watershed burned 66%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Keep drainage channel next to the Cal Fire facility clear of debris.
Page 92 California Geological Survey Site Number ___499__ Lockheed Burn Site Evaluation Form Page 2
Sketch Swanton Road crosses Winter Creek in an existing 30 inch diameter culvert. The watercourse is channeled several hundred feet upstream of the crossing adjacent to the CAL FIRE facility. The channel and pipe have cleared trash racks. The channel may experience increased flows during moderate storm periods due to increased runoff in the small portion of the upstream watershed that burned.
View (west) of culvert inlet at Swanton Road.
View (east) of upstream drainage channel.
Page 93 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 500 Reviewer C. Michael Huyette Date 9/1/09 Address Upper Archibald Creek Culvert. Quad Davenport Watershed/Drainage Archibald Creek watershed GPS location 37 03.281 122 13.298 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 415 ac. c. slope (average and range) 10/ 5-20% d. channel presence 3'w 4'd, channel grade 2-5% Observations 1. Percent of watershed burned 89%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if crossing is in use during storm events) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Keep drainage channel clear of debris.
Page 94 California Geological Survey Site Number ___500__ Lockheed Burn Site Evaluation Form Page 2
Description: The upper 36 inch diameter culvert on an unpaved road for Swanton-Pacific Ranch that crosses Archibald Creek (see Geologic Map of Archibald Creek Watershed) has recently been subjected to burial by debris flows with flooding, with debris having been deposited onto both the private road and the county road. This culvert is likely to be buried again from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high burned Archibald Creek watershed.
Page 95 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 501 Reviewer C. Michael Huyette Date 9/1/09 Address Archibald Creek Culvert crossing of Swanton Road. Quad Davenport Watershed/Drainage Archibald Creek watershed GPS location 37 03.248 122 13.535 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 415 ac. c. slope (average and range) 10/ 5-20% d. channel presence 6'w 6'd, channel grade 2-5% Observations 1. Percent of watershed burned 89%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if crossing is in use during storm events) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Keep drainage channel clear of debris. Restrict use when there is a chance of rain
Page 96 California Geological Survey Site Number ___501__ Lockheed Burn Site Evaluation Form Page 2
Description: Swanton Road crosses Archibald Creek in a 48 inch diameter culvert (see Geologic Map of Archibald Creek Watershed). The crossing has recently been subjected to burial by debris flows with flooding, with debris having been deposited onto both the private road and the county road. This culvert is likely to be buried again from increased flooding, sediment laden flooding, and debris flows resulting from increased runoff from the mostly moderate and high burned Archibald Creek watershed.
Page 97 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 502 Reviewer C. Michael Huyette Date 9/1/09 Address Queseria Creek Culvert on Swanton Road MP 1.33. Quad Davenport Watershed/Drainage Queseria Creek watershed GPS location 37 02.577 122 13.341 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 502a and 502b Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 594 ac. c. slope (average and range) 65/ 50-70% d. channel presence 12'w 5'd, channel grade 2% Observations 1. Percent of watershed burned 61%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 - 98 Fan alluvial wash other comments instream mostly cobbles, few boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low (if crossing is in use during storm events) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Keep drainage channel clear of debris. Avoid use during storms.
Page 98 California Geological Survey Site Number ___502__ Lockheed Burn Site Evaluation Form Page 2
Description: The Queseria Creek crossing at Swanton Road was replaced with a 12 foot wide, 5 foot high arch culvert since the 1998 flood event as part of the Queseria Creek Restoration Project. This culvert is likely to receive increased surface flows and have increased flooding, sediment laden flooding, and debris flows potential resulting from increased runoff from the mostly moderate and high burned Queseria Creek watershed.
Arch culvert watercourse crossing of Queseria Creek at Swanton Road.
Page 99 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 505 Reviewer C. Michael Huyette Date 9/2/09 Address Mill Creek Dam Quad Davenport Watershed/Drainage Mill Creek watershed GPS location 37 06.972 122 12.742 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 505a - 505c Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Dam 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other b. size 2406 ac. c. slope (average and range) 65/ 50-70% d. channel presence , channel grade
Observations 1. Percent of watershed burned 0
2. Geology: Formation or unit name (if available) qd lithology: quartz diorite fabric massive penetrative structures: yes no, type orientations regolith/soil: texture dg thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 1982 Fan alluvial wash other comments Reservoir partially filled by debris flow in 1982.
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other Dam face erosion. 10. Possible Risk to Life: High Moderate Low (to areas downstream from dam) 11. Possible risk to property: High Moderate Low
Page 100 California Geological Survey Site Number ___505__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Mulch dam face to reduce erosion potential.
Description: Although the Mill Creek Dam (76ft high, 250ft long, 35ft wide at crest, 223 acre-ft capacity) is upslope of the fire perimeter, it is understood from consulting reports that the Mill Creek dam lost much of its capacity from flooding in 1982 and a partial upstream side embankment failure. The dam and the reservoir are maintained by Lockheed and are periodically inspected by the State. There were no apparent fire affects to the reservoir area but vegetation growing on a portion of the downstream dam face burned at the right abutment. Latest dam Seismic Safety Evaluation was by Wahler Associates in August 1992 (Project LOC-104A) and the most recent Inundation Study for Mill Creek Dam 630 was in March 1993 by Ensign & Buckley Consulting Engineers.
Burned vegetation on downstream dam face at right abutment.
Page 101 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 506 Reviewer C. Michael Huyette Date 9/2/09 Address Boyer Creek Dam Quad Davenport Watershed/Drainage Boyer Creek subwatershed, drains to Big Creek watershed GPS location 37 05.840 122 12.419 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 506a - 506g Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Dam 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other eroded dam face. b. size 1354 ac. c. slope (average and range) 65/ 50-110% d. channel presence 6'w, channel grade 10- 20% Observations 1. Percent of watershed burned 32%
2. Geology: Formation or unit name (if available) Tsm lithology: Sandstone and shale fabric thin bedded penetrative structures: yes no, type orientations regolith/soil: texture GM-GC thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 1998 Fan alluvial wash other comments Reservoir mostly filled by debris flows in 82 and 98.
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 20% moderate 80% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 20%% surface rock 20%% total cover 40% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other Dam face erosion from burned vegetation and future over-topping events. 10. Possible Risk to Life: High Moderate Low (to areas downstream from the dam) 11. Possible risk to property: High Moderate Low
Page 102 California Geological Survey Site Number ___506__ Lockheed Burn Site Evaluation Form Page 2
12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Clear spillway of trees (leave stumps); Clean outlet pipe inlet; Have Safety Evaluation prior to next winter and breach dam to reduce the long-term potential for catastrophic failure. Description: The Boyer Creek dam and reservoir are within a subwatershed to Big Creek that was burned at a moderate to very high burn severity. The reservoir mostly silted-in during 1982 storms, creating a tulle-filled marsh. The dam is currently drained by a 60 inch diameter culvert and had about 6 feet of freeboard to a concrete emergency spillway at the time of this inspection. According to Lockheed Representative Fred R. Rust, the dam last overtopped in 1998. The overtopping eroded the embankment and left the downstream face with an average of 90 to 110 percent slope with the upper 6 feet nearly vertical and the spillway unsupported and overhanging . Chances of filling and overtopping the dam have been substantially increased because of the Lockheed fire. It is not clear if the dam is currently considered jurisdictional size by the State Division of Safety of Dams but, as with all High-Value Sites in this report, it should be evaluated for its safety prior to the next winter period.
Blocked inlet of 60 inch diameter drain pipe. Burned spillway bridge crossing.
Burned downstream dam face.
Page 103 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 507 Reviewer C. Michael Huyette Date 9/2/09 Address Flatcar bridge across Class II on Little Creek Road Quad Davenport Watershed/Drainage Little Creek watershed GPS location 37 04.552 122 12.136 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 507a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Flatcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other
b. size 1238 ac. c. slope (average and range) 65/ 50-80% d. channel presence 5'w, channel grade 25% Observations 1. Percent of watershed burned 95%
2. Geology: Formation or unit name (if available) gd lithology: Quartz diorite fabric massive penetrative structures: yes no, type orientations regolith/soil: texture dg thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency Fan alluvial wash other comments Recently installed bridge at NTMP point R-12.
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 20% moderate 80% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other Possible abutment wedge failure from burned logs. 10. Possible Risk to Life: High Moderate Low (if road is in use during storm events) 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Evaluation of west abutment by qualified consulting geologist or engineer.
Page 104 California Geological Survey Site Number ___507__ Lockheed Burn Site Evaluation Form Page 2
Description: A 75 foot long railcar bridge is located on a rocked access road from Swanton Road and crosses a Class II tributary to the North Fork Little Creek (see Geologic Map of Little Creek Watershed). Several logs on face of right (west) abutment under the bridge are missing post-fire and the slope under bridge appears to have a wedge failure developing in the upper third of the bridge supporting soils. The Swanton Pacific Ranch Resource Manager has been advised to have an engineering geologic evaluation for this bridge.
West bridge abutment showing apparent wedge failure.
Page 105 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 508 Reviewer C. Michael Huyette Date 9/2/09 Address Flatcar bridge across NF Little Creek Quad Davenport Watershed/Drainage Little Creek watershed GPS location 37 04.558 122 12.083 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 508a Camcorder, date-time stamp Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Flatcar Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other
b. size 1238 ac. c. slope (average and range) 65/ 50-80% d. channel presence 40'w, channel grade <5% Observations 1. Percent of watershed burned 95%
2. Geology: Formation or unit name (if available) gd lithology: Quartz diorite fabric massive penetrative structures: yes no, type orientations regolith/soil: texture dg thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 1998 Fan alluvial wash other comments Large 3 foot boulders in channel
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 20% moderate 80% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Replace burned sediment basin fabric debris screen.
Page 106 California Geological Survey Site Number ___508__ Lockheed Burn Site Evaluation Form Page 2
Description: A 75 foot long railcar bridge is located across the North Fork Little Creek (see Geologic Map of Little Creek Watershed). Large ±3 foot diameter boulders are in the creek channel. The bottom of the bridge is approximately 40 feet above the creek channel. A geotextile fabric sediment trap screen at the south abutment is melted and non- functional.
South bridge abutment showing riparian burn severity.
Page 107 California Geological Survey Burn Site Evaluation Form Lockheed Post-Fire Risk Assessment Site Number 509 Reviewer C. Michael Huyette Date 9/2/09 Address Bridge across Little Creek at Swanton Road Quad Davenport Watershed/Drainage Little Creek watershed GPS location 37 03.833 122 13.617 Sec. , T. , R. W, BL&M Photos Film, roll, frames Digital, frames 509a - 509c Camcorder, date-time stamp
Characterization 1. Structure(s) infrastructural element at risk: house business major road local road trailer tank culvert other Bridge 2. Watershed / hillslope feature characteristics: a. small watershed large watershed colluvial hollow steep slope cut slope other
b. size 1238 ac. c. slope (average and range) 65/ 50-80% d. channel presence 15'w, channel grade 2% Observations 1. Percent of watershed burned 95%
2. Geology: Formation or unit name (if available) Qal lithology: Cobble, gravel, sand and silt with boulders fabric unconsolidated penetrative structures: yes no, type orientations regolith/soil: texture GP-GM thickness unknown other 3. Dry ravel presence yes no volume characteristics 4. Evidence of past debris flow activity? Yes No estimated recency 97 -98 Fan alluvial wash other comments instream mostly cobbles, large boulders
5. Pre-fire vegetation grass chaparral trees hardwood grass woodland other Riparian 6. Soil burn severity (Parsons, 2003): high 0% moderate 0% low 0% 7. Post fire ground cover: vegetation/litter/leaf fall 0%% surface rock 0%% total cover 0% 8. Hydrophobic soil development: high moderate slight continuity of hydrophobic layer: high moderate low thickness of wettable layer above hydrophobic layer post-fire bioturbation None Moderate (5-20%) High (>20) type gopher ant hoof print Other 9. Potential post-fire hazards: flood sediment concentrated flood debris torrent future landslide potential from slope other future potential upstream bank failure. 10. Possible Risk to Life: High Moderate Low 11. Possible risk to property: High Moderate Low 12. Treatment options yes no surficial erosion control channel clearance/improvements structures (describe conditions and goals) other Monitor upstream adjacent creekbank during high flow storm periods.
Page 108 California Geological Survey Site Number ___509__ Lockheed Burn Site Evaluation Form Page 2
Description: A concrete single span bridge on Swanton Road crosses Little Creek where large boulders that were transported by past debris flows are present in the channel at the bridge site. An alder-covered ±20 foot wide by ±40 foot long bank slump upstream adjacent to the left abutment (when looking down stream) of the bridge directs stream flow into the concrete wing wall on the right abutment. Impact to the bridge from increased flooding, sediment laden flooding, and debris flows and upstream bank slumping resulting from increased runoff from the mostly moderate and high burn severity watershed appears likely.
Failing alder-covered south bank, upstream of south bridge abutment.
Page 108