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Jurisdictional Delineation: Waters of the United States and Streambeds

JURISDICTIONALDELINEATION:WATERS OF THE UNITEDSTATES

AND STREAMBEDS

Hidden Creeks EstatesLos Angeles County, California

Prepared for:First American Communities370 N. Westlake Blvd. #130

Thousand Oaks, California 91362

Contact: Mr. John Polito

Prepared By:Impact Sciences

803 Camarillo Rd., Suite ACamarillo, California 93012

(805) 437-1900

May 2007

Impact Sciences, Inc. i Hidden Creeks Estates860.001 May 2007

TABLE OF CONTENTS

Section Page

INTRODUCTION.......................................................................................................................................................1Project Description...........................................................................................................................................1

METHODOLOGY.......................................................................................................................................................7GPS Mapping ...................................................................................................................................................8

SITE DESCRIPTION...................................................................................................................................................8Watershed.........................................................................................................................................................8Topography ......................................................................................................................................................8Hydrology.........................................................................................................................................................9Soils..................................................................................................................................................................10Vegetation.......................................................................................................................................................10Functional Assessment of Jurisdictional Streams and Wetlands ............................................................11

DISCUSSION OF FINDINGS..................................................................................................................................12ACOE Waters of the United States and Wetland Areas (Section 404, Clean Water Act) andCDFG Streambeds (Sections 1600–1603, Fish and Game Code of California).......................................12

OFF-SITE RESOURCES ...........................................................................................................................................13

SUMMARY OF JURISDICTIONAL RESOURCES...............................................................................................22

REFERENCES............................................................................................................................................................23

APPENDICES

APPENDIX A – Site PhotosAPPENDIX B – Data Sheets

Jurisdictional Delineation

Impact Sciences, Inc. ii Hidden Creeks Estates860.001 May 2007

LIST OF FIGURES

Figure Page

1 Project Location and Property Boundary ..................................................................................................22a Hidden Creeks – Overall Study Area and Project Site Boundary .........................................................32b Hidden Creeks – Drainage Detail ............................................................................................................142c Hidden Creeks – Drainage Detail (cont’d)..............................................................................................152d Hidden Creeks – Drainage Detail (cont’d)..............................................................................................162e Hidden Creeks – Drainage Detail (cont’d)..............................................................................................172f Hidden Creeks – Drainage Detail (cont’d)..............................................................................................18

LIST OF TABLES

Table Page

1 On-Site Soils Associated with Waters and Streambeds and their HydrologicalCharacteristics.............................................................................................................................................10

2 Ecological Functions Associated with Stream and Wetlands on Hidden Creeks EstatesProject Site...................................................................................................................................................12

3 Summary of Waters, Wetlands, and Riparian Corridors within the Property Boundariesof the Hidden Creek Estates Project Site.................................................................................................19

4 Summary of Jurisdictional Areas (acres) Hidden creeks Development Project Site .........................22

Impact Sciences, Inc. 1 Hidden Creeks Estates860.001 May 2007

INTRODUCTION

This jurisdictional delineation report documents the findings of field investigation on the 259-acre

Hidden Creeks Estates project site (and an off-site portion tentatively planned for road access) during

delineation of the extent of “waters of the United States,” including wetlands, under federal jurisdiction,

and streambeds under California Department of Fish and Game (CDFG) jurisdiction. The property is

located north of State Route 118 (SR-118) and west of the City of Los Angeles community, Porter Ranch

(Figure 1, Project Location and Property Boundary). Primary drainages on the project site include

Browns Canyon Wash and Mormon Canyon, both USGS blue line streams, and their associated

tributaries (Figure 2a, Hidden Creeks – Overall Study Area and Project Site Boundary). Situated within

the lower reaches of the southern Santa Susana Mountains, current land uses on the project site consist of

cattle grazing, equestrian facilities and riding trails, and television and movie production facilities.

While conducting the delineation, Impact Sciences, Inc., evaluated hydrology, soils, vegetation, ordinary

high water marks, stream banks, and riparian vegetation. Figures detailing the findings are included

throughout this report. Data sheets are included in Appendix B of this report.

Project Description

The Hidden Creeks Estates development is proposed as a gated community with 183 single-family

residential lots and five residential equestrian lots, associated roadways and infrastructure, a 17-acre

public park, and a new equestrian boarding facility. The majority of the residential lots will be clustered

on a graded, centralized plateau currently used for ongoing filming operations and grazing.

The proposal will result in significant alterations to existing drainages and on-site hydrology, as well as

direct impacts to federal and state jurisdictional aquatic resources. Hydrologic impacts include

alterations to the rate, volume, timing, and direction of surface runoff. Direct impacts to aquatic

resources include proposed construction within state-regulated riparian habitats and direct fill of both

federal wetlands and other “waters of the United States,” and state-regulated streambeds.

Project Location and Property Boundary

FIGURE1

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SOURCE: Stantec Consulting, Inc. – November 2005

APPROXIMATE SCALE IN FEET

2400 1200 0 2400

n

CDFG

ACOE Wetland

ACOE

B

Study Area

oundary

Legend:

Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2f

Mason Avenue (Proposed)

Figure 2d

Legend:

Project Boundary

Figure Index Location

Approximate Hidden Creeks Drainage Location

Hidden Creeks – Overall Study Area and Project Site Boundary

FIGURE2a

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500 250 0 500

n



U.S. Army Corps of Engineers

Federal regulation of “waters of the United States” stems from Section 10 of the Federal Rivers and

Harbors Act of 1899, enacted to regulate activities within navigable waters. Passed in 1972, the federal

Clean Water Act regulates discharges into “waters of the United States.” Section 404 of the Clean Water

Act regulates activities, including fills placed into wetlands that are adjacent to navigable waters.

“Waters of the United States” are defined in the Code of Federal Registration 33 CFR §328.3:

a) The termwaters of the United States means

1) All waters which are currently used, or were used in the past, or may be susceptible to use in interstate orforeign commerce, including all waters which are subject to the ebb and flow of the tide;

2) All interstate waters including interstate wetlands;

3) All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats,potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which couldaffect interstate or foreign commerce including any such waters;

i) Which are or could be used by interstate or foreign travelers for recreational or other purposes; or

ii) From which fish or shellfish are or could be taken and sold in interstate or foreign commerce; or

iii) Which are used or could be used for industrial purpose by industries in interstate commerce;

4) All impoundments of waters otherwise defined as waters of the United Sates under the definition;

5) Tributaries of waters identified in paragraphs (a) (1) through (4) of this section;

6) The territorial seas;

7) Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs (a)(1) through (6) of this section….

b) The term wetlands means those areas that are inundated or saturated by surface or ground water at a frequencyand duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetationtypically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, andsimilar areas.

c) The term adjacent means bordering, contiguous, or neighboring. Wetlands separated from other waters of theUnited States by man-made dikes or barriers, natural river berms, beach dunes and the like are “adjacentwetlands.”

Army Corps of Engineers (ACOE) jurisdiction in non-tidal waters typically extends to the ordinary high

water mark (OHWM). The OHWM for intermittent streams, for example, can be determined by “the



fluctuations of water as indicated by physical characteristics such as clear, natural lines impressed on the

bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter

and debris, or other appropriate means that consider the characteristics of the surrounding areas” (33

CFR 328.3(e)). In arid areas of the southwest, the OHWM may occur at a lower level than where the

typical physical indicators are present, due to unusually high flows, not occurring on a typical annual

cycle. (Allen, et al., 2001)

In 1976, ACOE and the Environmental Protection Agency (EPA) adopted a regulatory definition, which

states that wetlands are:

Those areas that are inundated or saturated by surface or ground water at a frequency andduration sufficient to support, and that under normal circumstances do support, a prevalence ofvegetation typically adapted for life in saturated soil conditions. Wetlands generally includeswamps, marshes, bogs, and similar areas. (33 CFR 328.3(b))

In 1987, the ACOE published the Corps of Engineers Wetland Delineation Manual (1987 Manual) which is

used to determine the extent of its jurisdiction in wetlands. Subsequently, additional guidance

documents have been issued by the ACOE, which further clarify the use of the 1987 Manual.

The U.S. Supreme Court, in a 2001 opinion, found that wetlands and waters that are isolated from

navigable waters, should not be considered jurisdictional “waters of the United States” if the basis for

jurisdiction is use of the waters by migratory birds. The Court held that use by migratory birds did not

constitute sufficient reason to regulate these wetlands. However, if waters can be shown to have other

uses that constitute sufficient interstate commerce use, then they might constitute “waters of the United

States.” This determination shall be made independently of procedures described in the 1987 Manual.

The U.S. Supreme Court decision was made based on the jurisdiction of the waters and not on the

methods used to delineate waters. A site-specific evaluation of the ACOE’s jurisdiction is generally

required, although many site-specific decisions have already been made for various water bodies. These

decisions are regularly published on the ACOE District’s website.

If determined to be jurisdictional “waters of the United States” by the ACOE, most impacts to such areas

require approval under the authority of the Clean Water Act and its implementing regulations.

Section 404 Permits

The deposition of fill to an area delineated as “waters of the United States,” including wetlands, and

determined to be under the ACOE jurisdiction, require a permit or other approval by the ACOE

Regulatory Branch. Fill is broadly defined to include most materials (rock, soil, pilings, concrete, wood,



some incidental fallback of soil from earth-moving equipment, and in some cases additional water) that

might be discharged into a water or wetland.

Permitting requirements for a project vary depending on the nature and extent of project-related impacts

to jurisdictional resources. The ACOE issues individual and general permits, depending on the activity.

General permits may be “Nationwide,” “Statewide,” or “Regional” in scope. Both individual and general

permits require extensive review, as outlined in the Section 404(b)(1) guidelines. Both must be subject to

an alternatives analysis and public notice (and possibly public hearing), generally require mitigation, and

may be conditioned by both the ACOE district and by the state (under the state’s Section 401 certification

process). General permits are issued for categories of activities that are considered to have de minimus

impacts on the environment. General permits are typically issued to the ACOE with the provision that

applicants with projects that meet the permit conditions may be authorized to use the ACOE general

permit. According to the ACOE’s March 2000 nationwide permits (NWPs), if project impacts are greater

than 0.5 acre or impact greater than 300 linear-feet of a perennial streambed the project will not qualify

for coverage under the NWPs. All of the Nationwide Permits are due for reauthorization or revision in

2007.

Most Section 404 permits require mitigation for reducing overall impacts to net wetland area and

functions.

California Department of Fish and Game

The State of California regulates water resources under Sections 1600 to 1603 of the Fish and Game Code

of California. Section 1602 mandates that:

It is unlawful for any person to divert or obstruct the natural flow or substantially change the bed,channel, or bank of any river, stream, or lake designated by the department, or use any materialfrom the streambeds, without first notifying the department of that activity.

CDFG considers most natural drainages to be streambeds unless it can be demonstrated otherwise.

Streambeds are defined in the California State Register (Vol. 87, No. 9, Section 1.72) as follows:

A stream is a body of water that follows at least periodically or intermittently through a bed orchannel having banks and that support fish or other aquatic life. This includes watercourseshaving surface or subsurface flow that supports or has supported riparian vegetation.

CDFG jurisdiction includes ephemeral, intermittent, and perennial watercourses, and is often extended to

the limit of riparian habitats that are located contiguous to the water resource and that function as part of

the watercourse system. Section 2785(e) of the Fish and Game Code of California states, “Riparian habitat



means lands which contain habitat which grows close to and which depends on soil moisture from a

nearby freshwater source.”

Streambed Alteration Agreements

Any project that impacts CDFG jurisdictional areas, including fills, vegetation removal, or bridging,

requires a Section 1602 Streambed Alteration Agreement from CDFG. Much of the information necessary

to apply for ACOE Section 404 permits (e.g., project description, potential impacts, and mitigation

measures) is required for the Streambed Alteration Agreement application.

Regional Water Quality Control Board)

Section 401 of the federal Clean Water Act authorizes the State of California to certify that federal permits

and licenses do not violate the state’s water quality standards. The state’s implementing regulations to

conduct certifications are codified under the California Code of Regulations Title 23 Waters, Sections 3830

through 3869. Projects qualifying for an ACOE Section 404 permit must submit materials for review to

the appropriate Regional Water Quality Control Board and request a Section 401 certification. Much of

the information necessary to apply for ACOE Section 404 and CDFG Section 1602 permits (e.g., project

description, potential impacts, and mitigation measures) is required for the Section 401 Certification.

METHODOLOGY

To evaluate the extent of ACOE and CDFG jurisdiction on the project site, a literature search and a

jurisdictional delineation were conducted by Impact Sciences. All available literature relevant to the

jurisdictional determination and describing biological, soil, and hydrologic resources within the vicinity

of the site was examined prior to the field study. The literature examined for this report includes:

Soil Survey of Los Angeles County, California, West San Fernando Valley Area (United StatesDepartment of Agriculture [USDA], Natural Resources Conservation Service, Web Soil Survey 1.1,National Cooperative Soil Survey, 4/24/2006);

U.S. Fish and Wildlife Service’s National Wetland Inventory Map (NWI), Oat Mountain Quadrangle;

USGS Oat Mountain Quadrangle;

The Jepson Manual: Higher Plants of California;

The ACOE District’s website to determine if a jurisdictional determination has been made on thespecific waterbody; and

National List of Plant Species that Occur in Wetlands, Region 0 – California.



On January 17 through 20 and March 13 through 14, 2006, Impact Sciences biologists conducted field

delineations on the project site. The boundaries of all jurisdictional waters, including wetlands and

streambeds, and the extent of adjacent riparian vegetation were determined and mapped. Visual

observations of the OHWM, shoreline banks, and riparian vegetation were used to determine the extent

of ACOE and CDFG jurisdiction. Additionally, data documenting hydrology, soils, and vegetation were

collected at various sampling points.

GPSMapping

Jurisdictional boundaries were determined and mapped using resource-grade Trimble Global Positioning

System (GPS) Units with sub-meter accuracy. Where possible, “waters of the United States,” including

wetlands (as defined by the ACOE 1987 Manual) and stream corridors, were mapped utilizing the GPS

equipment. In areas with limited to no access, “waters of the United States” and CDFG streambeds/limits

of riparian vegetation were subsequently delineated using a combination of GPS mapping, aerial

photography, and on-site estimations of average streambed widths.

The jurisdictional areas calculated by Geographic Information Systems (GIS) during the analysis of the

delineation were mapped onto an ortho-aerial photograph.

SITE DESCRIPTION

The project site is located within the southern reaches of the Santa Susana Mountains near the western

edge of Los Angeles County. Existing uses within the project site boundaries consist of equestrian

facilities located in the southeastern part of the property, movie and television production facilities

located in the central-eastern part of the property, and cattle ranching facilities and associated access

roads located throughout the property.

Watershed

The proposed project site is located within the Bull Canyon sub-watershed, which is tributary to the Los

Angeles River Hydrological Unit, which itself is located within the South Coast Hydrologic Region. The

project site is located near drainage headwaters, where steep, erosional, generally south-draining faces

direct water toward the project site. The size of the watershed draining through the property is

approximately 2,250 acres (approximately 3.5 square miles).

Topography

Elevations within the Hidden Creeks Estates property range from approximately 2,145 feet above mean

sea level in the northernmost extent of the property to 1,350 feet in the southernmost, at the confluence of



Browns Canyon Wash and Mormon Canyon. Topography on the site ranges from rolling hills with

slopes of 5 percent or less to steep hillsides and highly eroded streambanks with maximum slopes in

excess of 60 percent. Erosional surfaces are the major landscape feature found throughout the property.

Steep hillsides, naturally erodable and unconsolidated soils, and the long-term impacts of cattle grazing

(such as loss of native vegetation, soil compaction, eroded streambanks, decreased rainwater infiltration

and increased overland surface flows) have all resulted in landscape features associated with high levels

of erosion. These features include slumped hillsides, a number of ephemeral washes, and the formation

of deeply eroded gullies with concomitant soil and vegetation loss.

Hydrology

Water is the driving force in creating and sustaining stream habitat and riparian vegetation. Apart from

the two primary channels of Mormon Canyon and Browns Canyon Wash, the dominant water sources for

the project site are surface and subsurface flows originating within the boundary of the project site.

Additional water sources include runoff from the Santa Susana Mountains to the north, most notably

within the Mormon Canyon and Browns Canyon Wash channels. In general, directional flows are

oriented to the south.

The project site can be divided into two distinct watersheds: Mormon Canyon to the east and Browns

Canyon Wash to the west (Figure 2a). On the eastern half, the project site contains the upper headwaters

of three tributaries to Mormon Canyon, as well as three segments of the mainstem of Mormon Canyon.

On the western half, the project site contains one tributary to Browns Canyon Wash and two segments of

the mainstem of Browns Canyon Wash. Additionally, the project site contains the confluence of the two

main streams where Mormon Canyon enters Browns Canyon Wash. The upstream reaches of both

Mormon Canyon and Browns Canyon Wash are located off the project site to the northeast and northwest

respectively.

The dominant hydrologic feature on the project site is gently to steeply eroded ephemeral washes

tributary to the two primary channels. In general, erosional forces within the tributaries steadily increase

moving downstream, and then decrease prior to entering the main channels. Both Browns Canyon Wash

and Mormon Canyon flow through steep-walled canyons upstream and north of their convergence at the

southernmost edge of the project site. Other hydrologic features on the project site include a limited

number of flat and depressed areas that contain vegetative and hydrologic characteristics associated with

both seasonal and permanent wetlands.



Soils

Soils within the property boundary (Table 1, On-Site Soils Associated with Waters and Streambeds and

their Hydrological Characteristics), as mapped by the Natural Resources Conservation Service (NRCS),

are Balcom and Gazos series silty clay loam with slopes between 15 and 50 percent. Additionally, a small

distribution of Lopez series shaley clay loam with slopes of 30 to 50 percent exists outside the propertyboundary, but within an area of interest.

Table 1On-Site Soils Associated with Waters and Streambeds and their Hydrological Characteristics

Mapped SoilSoil Characteristics

Descriptive terms are defined in SCS soil surveys.Hydric(NRCS)

BalcomWell drainedLow to high runoffModerate to moderately slow permeability

Non-hydric

GazosWell drainedHigh to very high runoffModerately slow permeability

Non-hydric

LopezSomewhat excessively drainageRapid to very rapid runoffModerate permeability

Non-hydric

Vegetation

A combination of topography, hydrology, and land use strongly dictates the extent and types of

vegetative communities found on the project site; specifically, vegetative types are largely determined by

relative slope, the location of surface and subsurface flows, and the presence or absence of cattle grazing.

A total of 15 plant communities were identified on the project site, including:

Mixed Willow Riparian Woodland,MixedCoast Live Oak-Willow Riparian Woodland,Mulefat Scrub,Mixed Mulefat-Bulrush/Cattail-Rush Wetland,Mulefat Scrub-Non-Native Grassland,Non-Native Grassland,Coast Live Oak Woodland,Mixed California Black Walnut-Coast Live Oak Woodland,California Walnut Woodland,Mixed Sage Scrub,Coastal Sage Chaparral Scrub,California Sagebrush Scrub,Chamise Chaparral,Tamarisk Scrub, andDisturbed



Upland Vegetation

The vast majority of the project site is comprised of upland vegetative communities. In general, on-site

upland vegetation can be divided into two categories: vegetation readily accessed by cattle and thus

impacted by grazing, and inaccessible vegetation that exhibits little to no grazing impacts. Areas heavily

grazed include easily accessed, gentle- to medium-sloped hillsides, ridges, and plateaus. Non-native

annual grasses dominate these areas. Areas marginally impacted by grazing include dry, steep hillsides

in which sparse groundcover and the lack of regular grazing allow native vegetation to persist. In

general, non-native grasslands/disturbed mixed sage scrub generally comprises these areas. Upland

areas not impacted by grazing include remote canyons and ravines with especially steep slopes in which

native vegetation was never supplanted by introduced grasses. These areas include mixed sage scrub,

coastal sage-chaparral scrub, and chamise chaparral vegetation communities.

Riparian and Wetland Vegetation

Of the 15 plant communities identified above, mixed willow riparian woodland, mixed coast live oak-

willow riparian woodland, mulefat scrub, mixed mulefat-bulrush/cattail-rush wetland, coast live oak

woodland, mixed California black walnut-coast live oak woodland, and California walnut woodland are

associated with on-site stream channels and riparian corridors. The locations, characteristics, and extents

of these plant communities within the Hidden Creeks Estates project site are discussed in detail in the

following sections.

Functional Assessment of Jurisdictional Streams and Wetlands

All open space performs various and multiple ecological functions. The degree to which functions are

performed depends on both physical (e.g., location, size, soils, and available moisture) and biological

characteristics (e.g., species dominance, composition, diversity, and spacing). Examples of ecological

functions performed by ACOE and CDFG jurisdictional aquatic resources include wildlife habitat,

biofiltration, groundwater recharge, stormwater attenuation, shoreline or streambank stabilization, and

sediment movement or trapping.

While functions may be performed with varying effectiveness, the values of any given stream/riparian

corridor are related to the degree to which functions are performed and their relationship to the resources

which are of concern to local, regional, state, and national interests.

The water resources on the Hidden Creeks Estates project site vary considerably in the degree to which

functions are performed. General ecological functions associated with the project site are described

below in Table 2, Ecological Functions Associated with Stream and Wetlands on Hidden Creeks



Estates Project Site. A more-detailed functional assessment for specific sites within the proposed project

boundary appears in Table 3, Summary of Waters, Wetlands, and Riparian Corridors within the

Property Boundaries of the Hidden Creek Estates Project Site, in the Discussion of Findings section.

Table 2Ecological Functions Associated with Stream and Wetlands on Hidden Creeks Estates Project Site

Function Performance – Qualitative Ratings of Opportunity and EffectivenessWildlife Habitat Characteristics of high functions and values associated with wildlife habitat are areas of

adequate size, buffers from disturbances, shelter, minimum of disturbances, availabilityof food plants and water, and ability to move to other habitat areas. The HiddenCreeks Estates site exhibits all of these characteristics.

Biofiltration/NutrientRetention or Cycling

The riparian vegetation along the creeks absorbs nitrates from livestock waste andrunning water absorbs oxygen, necessary to decrease otherwise high levels ofbiological oxygen demand (BOD). Both of these factors aid in denitrification and thebreakdown of organic wastes from cattle and wildlife. These functions are high alongBrowns and Mormon Canyons, and to a lesser extent along the center drainage.

ShorelineStabilization/SedimentRetention

Shoreline stabilization occurs where sufficient vegetation is present along streamcorridors to control streambank erosion. In those areas easily accessed by cattle,shoreline stability is minimal due to the lack of streambank vegetation, as well as theslumping of banks resulting from trampling. Most of the sparsely vegetatedstreambanks are eroding and contribute to the quantity of sediment movingdownstream, leading to a low-value determination for these areas.

Stormwater Attenuation Stormwater attenuation in the system is affected by widespread soil compaction andthe gradient (slope) that exists throughout the project site. The greatest potential forstormwater attenuation is found along the mainstem of Browns Canyon Wash, where astormwater/sediment retention dam is located just off the project site, the uppertributary to Mormon Canyon, and the mainstem of Mormon Canyon, the uppertributary to Browns Canyon Wash.

Groundwater Recharge Although subsurface flows (baseflow) constitute an important component of the site’shydrology, there are no major groundwater resources within the boundaries of theproject site, which is characterized by medium to high slopes. Subsequently, potentialrecharge of onsite groundwater resources will not be discussed further.

DISCUSSION OF FINDINGS

ACOE Waters of the United States and Wetland Areas (Section 404, Clean Water Act)and CDFG Streambeds (Sections 1600–1603, Fish and Game Code of California)

The project site contains the upper headwaters of three tributaries to Mormon Canyon, three segments of

the Mormon Canyon mainstem, one tributary to Browns Canyon Wash, and two segments of the Browns

Canyon Wash mainstem. All stream channels on the project site are classified as riverine by the

hydrogeomorphic (HGM) system, which is a functional assessment methodology (Brinson, 1993). The



two mainstems are classified as riverine, perennial streambeds by the Cowardin classification system

(Cowardin, 1979), while the tributaries are classified as riverine, intermittent.

Assuming an OHWM and an extant hydrologic connection with a definable “navigable waters of the

United States,” these stream channels fall under the jurisdiction of the ACOE. Since all waters on the

project site eventually flow to Browns Canyon Wash, a tributary to the Los Angeles River (defined as

“navigable waters of the United States”), all stream channels within the project site meet the jurisdictional

definition of “waters of the United States,” pursuant to Section 404 of the Clean Water Act. Additionally,

two separate areas, one located within the project site boundary and one located off site, potentially meet

the definition of “wetlands adjacent to waters (other than waters that are themselves wetlands).”

CDFG riparian corridors include the streambed and channel, extending to the top of the bank, at a

minimum, and to the outward extent of the outer edge of the canopy of riparian vegetation, if a canopy is

present. All streams and riparian vegetation on the project site are regulated by CDFG.

The delineation of ACOE and CDFG jurisdictional areas is shown in Figure 2a and detailed throughout

Figures 2b through 2f, below.

Individual stream reaches within the property boundaries of the Hidden Creeks Estates project site are

summarized in Table 3, Summary of Waters, Wetlands, and Riparian Corridors within the Property

Boundaries of the Hidden Creek Estates Project Site, and Table 4, Summary of Jurisdictional Areas

(acres) – Hidden Creeks Development Project Site. Vegetative communities, functional assessments,

and jurisdictional areas are given for each reach.

OFF-SITE RESOURCES

Off-site jurisdictional resources located outside of the upper eastern border of the project site (Figure 2f

and Site Photos in Appendix A) that have the potential to be impacted by the construction of an access

road (continuation of Mason Ave.) include:

Upper reaches of the on-site stream segments described earlier in Table 3 as “Upper tributary toMormon Canyon; Mormon Canyon mainstem segments;”

An approximately 0.33-acre site that potentially meets the definition ACOE “wetlands adjacent towaters.” This is described as a mixed mulefat-bulrush/cattail-rush wetland. A more detaileddescription of this location can be found in Appendix B, Wetland Determination Data Form B titled“Off-Channel Mormon Canyon Headwater;” and

CDFG

ACOE WetlandACOE

Boundary

Legend:

Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2f


Figure 2d

Legend:

Project Boundary



Hidden Creeks – Drainage Detail

FIGURE2b

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n

CDFG

ACOE WetlandACOE

Boundary

Legend:

Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2fM

ason Avenue (Proposed)Figure 2d

Legend:

Project Boundary




FIGURE2c

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n

CDFG

ACOE WetlandACOE

Boundary

Legend:

Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2fM

ason Avenue (Proposed)Figure 2d

Legend:

Project Boundary




FIGURE2d

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n

CDFG

ACOE WetlandACOE

Boundary

Legend:

Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2f


Figure 2d

Legend:

Project Boundary




FIGURE2e

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CDFG

ACOE WetlandACOE

Boundary

Legend:


Mor

mon

Can

yon

Browns Canyon Wash

Figure 2b

Figure 2c

Figure 2e

Figure 2f


Figure 2d


Legend:

Project Boundary




FIGURE2f

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Table 3Summary of Waters, Wetlands, and Riparian Corridors within the Property Boundaries of the Hidden Creek Estates Project Site

Functional Assessments

Figure Stream Reach Vegetative Communities and General DescriptionWildlifeHabitat

Biofiltration/Nutrient

Retention orCycling


StormwaterAttenuation

Headwaters ofupper tributary toMormon Canyon

California walnut woodland (i.e., southernCalifornia black walnut [Juglans californica], coastlive oak [Quercus agrifolia]) dominant throughoutreach; dense understory (i.e., mulefat [Baccharissalicifolia], poison oak [Toxicodendron diversilobum])in upper reaches, relatively open canopydownstream; minimal to no impacts from cattlegrazing; coastal sage-chaparral scrub buffercommunity (i.e., toyon [Heteromeles arbutifolia],ceanothus [Ceanothus sp.], scrub oak [Quercusdumosa], California sagebrush [Artemisia californica])

High;considerableusage bywildlife

High; denseriparian andbankvegetation

High; mature,undisturbedvegetation;westernheadwatersusceptible toerosion fromroad cut

High; densecanopy, thickunderstory,and infiltrationcapacity ofpredominantlysandy soils

2b

Upper tributary toMormon Canyon;Mormon Canyonmainstem segments

Coast live oak woodland in upper reach; steeplyeroded and sparsely vegetated ravine; off-channelmulefat scrub (see Photo 1); mixedwillow riparianwoodland (i.e., western sycamore [Platanusracemosa], willow [Salix sp.]) at mainstem;understory includes California blackberry (Rubusursinus); see Photo 2; mainstem not accessed bycattle; this reach also contains small CDFG riparianarea off mainstem heavily impacted by grazing

Medium inupper reaches;high nearmainstem

Medium; lackof bankvegetation inupper reach

Low in upperreaches due tograzingimpacts; highnear and atmainstem

Medium foroverall reach;erosion andlack of bankvegetation

2c

Middle tributary toMormon Canyon

Headwaters of this reach highly impacted bygrazing and adjacent movie production facilitiesand lack riparian canopy and bank vegetation;highly erodable ephemeral wash leads to steep,incised ravine; coast live oak woodland in middlereach eventually leads to mixedwillow riparianwoodland nearing mainstem

Low in upperreaches;medium tohigh in lowerreach

Low in upperreaches due tograzing;medium tohigh in lowerreach

Low in upperreaches due tograzingimpacts;medium inlower reach

Low in upperreaches due tocompactedsoils and higherosion;medium inlower reach






Retention orCycling



Headwaters oflower tributary toMormon Canyon(Center Drainage)

Headwaters of this reach highly erosional; impactsfrom grazing and road cut (see Photo 3); lack ofbank vegetation and riparian canopy; lower reachwithin ravine also highly erosional and lackscanopy; bank and buffer vegetation primarilyconsists of disturbed mixed sage scrub (i.e., non-native grasses mixed with black sage [Salviamellifera], toyon, California sagebrush); mulefatwithin stream channel

Low; lack ofripariancanopy andbankvegetation

Low; highlyeroded andlackingriparianvegetation

Low;ephemeralwash in upperreach highlysusceptible toerosion

Low due toimpacts fromgrazing,roadcuts,productionfacilities

Lower tributary toMormon Canyon(Center Drainage)

California walnut woodland in upper reach, coastlive oak woodland in lower reach with densecanopy; understory includes toyon; area notdirectly impacted or accessed by cattle

Medium;dense canopy;considerableunderstory

Medium;impacted byupstreamareas

Medium;impacted byupstreamareas

Medium2c (cont’d)

Mormon Canyonmainstem segment

Mixed willow riparian woodland; dense canopyand thick understory; moderately disturbed areawith one concrete road crossing; mature stands ofcoast live oak within upper riparian zone

High; maturetrees andcomplexunderstoryvegetation


High; matureriparian treesand densevegetation

High; presenceof spreadingzones anddensevegetation

Westernheadwaters oftributary to BrownsCanyon Wash

Headwaters of this reach undisturbed and notimpacted by grazing; high-sloped ravines withmoderate to high levels of erosion; narrow riparianzone with sage scrub (i.e., mulefat mixed withpoison oak, laurel sumac [Malosma laurina],monkeyflower [Mimulus aurantiacus], lemonadeberry [Rhus integrifolia], toyon; coast live oakcanopy in lower reaches)

High;undisturbedarea with richplant diversity


Medium; areais highlyerosional

Medium; highslopes andnarrowcanyons

2d

Tributary (upperreach) to BrownsCanyon Wash

Entire reach impacted by cattle; coast live oakcanopy with general lack of understory; non-nativegrassland buffer community west of drainage;grassland/mixed sage scrub buffer communitypredominant east of drainage

Medium dueto grazingimpacts

Medium;general lack ofbankvegetation andcomplexunderstory

Low due tograzingimpacts

Mediumthroughoutreach






Retention orCycling



Tributary (middlereach) to BrownsCanyon Wash

Reach includes potential off-channel wetland(mulefat, rush [Juncus sp.], bulrush [Scirpus sp.])highly impacted by grazing (see Photo 4;mixedwillow riparian woodland in tributary channel withmature sycamore, cottonwood [Populus fremontii],and willow)

High invicinity ofmixed riparianwoodland andwetland

High; complexand denseunderstory;presence ofwetlandcommunity

High; densebankvegetation

High; presenceof areas withpotential forincreasedhydro-period

2d (cont’d) Eastern headwatersof tributary toBrowns CanyonWash

Headwaters of this reach highly eroded ephemeralwashes; impacts from grazing and road cut;streambed vegetation dominated by mulefat andlack of bank vegetation; non-nativegrassland/disturbed sage scrub buffer community;oak canopy in lower reach with minimal bankvegetation (see Photo 5) and high erosion

Low; highlyerosionalephemeralwashes withminimalvegetation

Low; lack ofbank andriparianvegetation

Low; highlyerosional dueto grazingimpacts androad cut

Low

Tributary (lowerreach) to BrownsCanyon Wash

Coast live oak woodland community; large,contiguous riparian canopy; non-native grasslandcommunity buffer community along eastern side ofchannel; non-native grassland/disturbed sage scrubbuffer community along western side

Medium dueto grazingimpacts

Medium; lackof complexunderstory

Medium;minimal bankvegetation

Medium

Browns CanyonWash uppermainstem segment

Reach impacted by road along western bank; lowerreach impacted by off-site, downstreamsediment/flood control dam (Photo 6) and large on-site road cut (Photo 7); stream primarily erosionalwith transition to depositional at road cut (roughly450 feet upstream of dam); mixed willow riparianwoodland in lower reach; dense but narrowriparian zone with mixed sage-scrub buffercommunity in upper reach; large stand of mulefatscrub upstream of dam within depositional area

High; dense,complexunderstory;moderatecanopy; noimpacts fromgrazing; highplant diversity

High; densebankvegetation

Medium;segments ofreach erosional

High;downstreamsediment/flood controldam createslargedepositionalarea

2e

Browns CanyonWash lowermainstem segment

Low gradient; channel between road on westernbank and small developed area on eastern bank;coast live oak woodland; sparse understory

Medium;disturbed areadue to roadand adjacentdevelopment

Medium;sparseunderstory

Medium; reachlacks sedimentdue toupstream dam

Medium

2f Off-site resources N/A N/A N/A N/A N/A



Table 4Summary of Jurisdictional Areas (acres)Hidden creeks Development Project Site

DrainageACOEWatersAvg. Width/Area ACOEWetlands

CDFG StreambedsAvg. Width/Area

Mormon Canyon mainstemsegment

14 feet/0.6 0.00 4.25*

Upper tributary to MormonCanyon

5 feet/0.4 0.00 5.8*

Middle tributary to MormonCanyon

10 feet/0.4 0.00 1.75*

Center Drainage 5 feet/0.17 0.00 3.5*Browns Canyon Wash 10 feet/0.35 0.00 2.5*Main tributary to Browns CanyonWash

8 feet/1.35 0.32 9.71*

Total (acres) 3.38 0.32 27.51Off site 0.31 0.33 4.65

*Acreage calculation based on habitat polygon area, not channel width.

Two channels tributary to Browns Canyon after passing through a neighboring residentialdevelopment, presently under construction. One of these channels comprises ACOE and CDFGresources and, aside from some mulefat and mugwort, both channels are vegetated primarily withcoastal sage chaparral scrub and mixed sage scrub plant species.

SUMMARY OF JURISDICTIONAL RESOURCES

This jurisdictional delineation report documents the extent of “waters of the United States,” including

wetlands under federal jurisdiction and streambeds under CDFG jurisdiction on the Hidden Creeks

Estates project site. Based on field studies employing sub-meter GPS equipment and observations from

aerial photography (field verified), within the Hidden Creeks project boundary the total area of “waters

of the United States” under ACOE jurisdiction is 3.38 acres, and wetlands under ACOE jurisdiction is 0.32

acre. Streambeds and riparian corridors under the jurisdiction of the CDFG total 27.51 acres.

Outside the project boundary, but within 300 feet of the proposed access road, are found 0.31 acre of

ACOE “waters of the United States,” 0.33 acre of ACOE wetlands, and 4.65 acres of CDFG streambeds.

Impact Sciences recommends concurrence with this delineation be obtained from the ACOE and CDFG

prior to commencement of any development planning activity. If ACOE and/or CDFG do take

jurisdictionof any on-site waters/streambeds, a determination of the extent of jurisdiction impacts may be



determined by overlaying the development plans on an aerial map at that time. Activities that impact

delineated areas may need permits, with mitigation required as conditions of those permits.

Coordination between Impact Sciences and the site planners is essential to ensure that regulatory and

procedural changes have not occurred subsequent to anticipated agency concurrence with this report.

REFERENCES

CaliforniaDepartment of Fish and Game. 2005. Fish and Game Code of California.

Code of Federal RegulationsVol. 33 Part 200 to End. July 2000. U.S. Government Printing Office.

Cowardin, L. M., et al. 1979. “Classification of wetlands and deepwater habitats of the United States.”U.S. Fish and Wildlife Service. Washington, D.C.

Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. “Technical ReportY-87-1.” U.S. Army Engineer Waterways Experiment Station. Vicksburg, MS.

Hickman, James C. 1993. The Jepson Manual: Higher Plants of California. University of California Press,Berkeley, CA.

U.S. Department of Agriculture, Natural Resources Conservation Service. April 14, 2006. Soil Survey ofLos Angeles County, California, West San Fernando Valley Area, Web Soil Survey 1.1, NationalCooperative Soil Survey.

APPENDIX ASite Photos

Mor

mon

Can

yon

Browns Canyon Wash


Legend:

Project Boundary


Photo Location and Direction

OS3

OS2

1

3

X

7

5

6

4

2

OS1

Hidden Creeks – On-Site and Off-Site Photo Locations

APPENDIXA

860-001•07/06


NOT TO SCALEn

Photo 1 Photo 2 Photo 3

Photo 5 Photo 6 Photo 7

Photo 4

Hidden Creeks – On-Site Photos

APPENDIXA

860-001•07/06


OS1

OS2

OS3

Hidden Creeks – Off-Site Photos

APPENDIXA

860-001•07/06


APPENDIX BData Sheets

STREAM DATA FORM GPS Data taken: Yes No –Western drainageProject / Site: Hidden Creeks Sample Plot # Browns Cyn Wash (Blue line)Owner/Developer: Field Date: 1/20/06Normal Circumstances? No – major flood control structure Lat./Long.:Tributary to: Los Angeles River County: L.A.Adjacent land use: equestrian, upstream park -near pristine State: California

VEGETATION: Buffer Community Type:Riparian Tree Species, % Cover Mature? Riparian/Hydrophytic Herb. Species % Cover X=Native

Populus fremontii Poison oakSalix Yes Yerba santaPlatanus racemosa Yes A. californicaJ. californica ToyonOaks, Specify: Coast Live Yes

Riparian Sapling / Shrub SpeciesMulefat (large stand at dam)Umbrella sedgeWater cress

Comments: high quality conditions

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: some erosion and incision

HYDROLOGY Source of Water: Spring/Seep ; Urban/Agricultural Runoff ; Can’t Determine ; OtherMaximum Depth of inundation: in. Spring – groundwater discharge and surface runoffDepth to Water Standing in Pit: >16 in. Permanent flows Intermittent flows Temporary flowsDepth to Saturated Soil: >16 in. Steep Gradient Moderate Gradient Low Gradient

Indicators:Buffer width; Ave. Width Ft. DitchedChannel Banks or OHWM present:

Yes No Buffer Continuous for length Graded –Detention basinGroundwater Recharge? Yes at dam; NoComments: High quality habitat

Hydrology altered by detention basin formed by large stacked concrete dam

STREAM CHARACTERISTICS

Stream Width Average: 10 Feet Recent Erosion Evident Yes; NoStream Length (field or map calculation: 1384 Feet

Watershed Area: 3.5 Square MilesComments: good habitat and pooling over entire reach

Determined By: Brody/Ferry Impact Sciences, Inc.

STREAM DATA FORM GPS Data taken: Yes No (ACOE centerline)Project / Site: Hidden Creeks Sample Plot # Main Trib to Brown’s Cyn (blue line)Owner/Developer: Forestar Real Estate Group Field Date: 1/19/06Normal Circumstances? Yes Lat./Long.:Tributary to: Browns Canyon Wash County: L.A.Adjacent land use: Cattle grazing State: California


Populus fremontiiSalix (lower reach) YPlatanus racemosa (lower reach YCottonwood 1 YOaks, Specify: Coast Live 70 Y

Riparian Sapling / Shrub SpeciesMulefat – isolated stands assoc. w/

wetland seep (lower reach)

Bulrush & Willows – coarse thicket

Comments: upper reaches – all sage scrub community – yerba buena to mulefat (channel + 5 ft buffer)Lower reaches – oak, mulefat

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: Stream substrate mostly sand, but sandy loam in lower reaches.

HYDROLOGY Source of Water: Spring/Seep ; Urban/Agricultural Runoff ; Can’t Determine ; OtherMaximum Depth of inundation: in. Light flow in lower reaches; temp.- rain eventsDepth to Water Standing in Pit: >16 in. Permanent flows Intermittent flows Temporary flowsDepth to Saturated Soil: >16 in. Steep Gradient Moderate Gradient Low Gradient

Indicators:Buffer width; Ave. Width 3 Ft. DitchedChannel Banks or OHWM present:

Yes No Buffer Continuous for length Graded – road crossingsGroundwater Recharge? Yes ; NoComments: Leads to dam; ends at mulefat thicket (depositional area)


Stream Width Average: 8 Feet ACOE Recent Erosion Evident Yes; NoStream Length (field or map calculation): 7300 Feet

Watershed Area: Project = 3.5 Square MilesComments: Impaired with multiple road crossings.

Determined By: RC Brody/Mike Ferry Impact Sciences, Inc.

STREAM DATA FORM GPS Data taken: Yes No –No BluelineProject / Site: Hidden Creeks Sample Plot # Center DrainageOwner/Developer: Field Date: 1/17/06Normal Circumstances? No – ranched and grazed Lat./Long.:Tributary to: Mormon Canyon (no blue line) County: L.A.Adjacent land use: ranching/farming/equestrian State: California


Populus fremontii ToyonSalix Yerba buenaPlatanus racemosa Black sageJ. californica Upper reach Yes Non-native grasses 40-50 %Oaks, Specify: Coast Live, scrub yes (introduced annual)

Riparian Sapling / Shrub Species SumacMulefat Arundo in places (stream bottom)Juglans californica – upper reach

Bulrush & Willows – coarse thicket

Comments: riparian buffer sparse in upper reachOak woodland in lower reach

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: mostly sand, but sandy loam in lower reaches only

HYDROLOGY Source of Water: Spring/Seep ; Urban/Agricultural Runoff ; Can’t Determine ; OtherMaximum Depth of inundation: in.Depth to Water Standing in Pit: >16 in. Permanent flows Intermittent flows Temporary flowsDepth to Saturated Soil: >16 in. Steep Gradient Moderate Gradient Low Gradient


Yes No Buffer Continuous for length GradedGroundwater Recharge? Yes ; NoComments: impaired from grazing/ road cuts/ grading

Multiple culvert inputs from road w/ related erosion


Stream Width Average: 4 Feet ACOE Recent Erosion Evident Yes; NoStream Length (field or map calculation: ACOE 2115 Feet

CDFG 3031Watershed Area: 3.5 Square MilesComments: ephemeral – dry wash

Impaired w/ fill in upper reachesHealthy oak woodland in lower reaches


STREAM DATA FORM GPS Data taken: Yes NoProject / Site: Hidden Creeks Sample Plot # Mormon Canyon (blue line)Owner/Developer: Forestar Real Estate Group Field Date: 1/18/06Normal Circumstances? Yes Lat./Long.:Tributary to: Browns Canyon Wash County: L.A.Adjacent land use: Some equestrian, 30 % grazed (to west) State: California


Populus fremontii Sparse Y UplandSalix Large stand Y Coast sagebrush 40 %Platanus racemosa Sparse Y Black sageJuglans californica Sparse Y ToyonOaks, Specify: Coast Live 30% Y Laurel sumac

Riparian Sapling / Shrub SpeciesMulefat – isolated stands Y

- cattail Non-native grass 40%

Bulrush & Willows – large thicket

Comments:

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments:

HYDROLOGY Source of Water: Spring/Seep ; Urban/Agricultural Runoff ; Can’t Determine ; OtherMaximum Depth of inundation: in. Base flow and direct rainfallDepth to Water Standing in Pit: >16 in. Permanent flows Intermittent flows Temporary flowsDepth to Saturated Soil: >16 in. Steep Gradient Moderate Gradient Low Gradient


Yes No Buffer Continuous for length GradedGroundwater Recharge? Yes ; No Multiple trail and road crossingsComments: Possibly perennial with some pooling and wetlands


Stream Width Average: ACOE 9 Feet Recent Erosion Evident Yes; NoStream Length (field or map calculation: 1855 Feet

Watershed Area: Project = 3.5 Square MilesComments: Unimpaired – near natural state

Some incision – possibly due to upstream grazingHeadwaters: sulfur in stream


STREAM DATA FORM GPS Data taken: Yes NoProject / Site: Hidden Creeks Sample Plot # Main upper tribs to Mormon CynOwner/Developer: Field Date: 3/13/06Normal Circumstances? Yes, but grazed Lat./Long.:Tributary to: Mormon Canyon County: L.A.Adjacent land use: State: California


Populus fremontii ChaparralSalix -toyonPlatanus racemosa -ceanothusJuglans -scrub oakOaks, Specify: Valley -Coastal sagebrush

Riparian Sapling / Shrub SpeciesWalnut/Mulefat riparian corridor 50%Coast Live Oak canopy 90%

Comments: More chaparral in streambed upstream, closer to Mormon Cyn becomes more riparian

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: some erosion and incision, rocky substrate

HYDROLOGY Source of Water: Spring/Seep ; Urban/Agricultural Runoff ; Can’t Determine ; OtherMaximum Depth of inundation: in. Source: Other, natural surface runoffDepth to Water Standing in Pit: >16 in. Permanent flows Intermittent flows Temporary flowsDepth to Saturated Soil: >16 in. Steep Gradient Moderate Gradient Low Gradient


Yes No Buffer Continuous for length GradedGroundwater Recharge? Yes ; NoComments:


Stream Width Average: 5 feet ACOE Recent Erosion Evident Yes; NoStream Length (field or map calculation): 2960 Feet Erosion: fill at road crossing

Watershed Area: 3.5 Square MilesComments: Dry oak-lined washDetermined By: R.C. Brody Impact Sciences, Inc.

STREAM DATA FORM GPS Data taken: Yes NoProject / Site: Hidden Creeks Sample Plot # Lower trib to Mormon Cyn (from west)Owner/Developer: Forestar Real Estate Group Field Date: 1/19/06Normal Circumstances? Heavily grazed Lat./Long.:Tributary to: Mormon Canyon County: L.A.Adjacent land use: Cattle Grazing State: California


Populus fremontiiSalix 10 YPlatanus racemosa Non-native grassesJuglans 20 YOaks, Specify: Valley 20 Y

Riparian Sapling / Shrub SpeciesWalnut/Mulefat riparian corridor 50%Coastal sagebrush

Comments: More chaparral in streambed upstream, closer to Mormon Cyn becomes more riparian

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: Erosional due to grazing



Yes No Buffer Continuous for length GradedGroundwater Recharge? Yes ; NoComments:


Stream Width Average: 10 feet ACOE Recent Erosion Evident Yes; NoStream Length (field or map calculation): 1394 Feet ACOE

2360 feet CDFGWatershed Area: 3.5 Square MilesComments: Steep/eroded banks due to heavy grazingDetermined By: R.C. Brody/ Mike Ferry Impact Sciences, Inc.

WETLAND DETERMINATION DATA FORM 1987 ACOE WETLANDS DELINEATION MANUAL

Project Site: Hidden Creeks Sample Plot #: Off-channel wtld (trib to Browns)Applicant: Field Date: 1/25/06Normal Circumstances?: No Section:Atypical Situation?: Newly grazed County: L.A.Problem Area?: State:

VEGETATION: Community Type:Tree Species, Indicator Status, %Cover Grass / Forb Species, Indicator Status, % CoverSalix lasiolepis, FACW, 10-15 % Juncus sp., OBL, 20%

Scirpus sp., OBL, 40%Speedwell? Veronica? Fescue sp., 20%

Sapling / Shrub Species, Indicator Status, % Cover Woody Vine Species, Indicator Status,Mulefat, FACW, 10%

Percent of Dominant Species Classified as OBL, FACW, or FAC: 100%Comments: Greater than 50% of the dominant species are hydrophytic species

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4 in4-8 in Clay - loam8-12 in 10 yr 2/112-16 in 10 yr 2/1Comments: all dominant plant species – OBL or FACW

Abrupt change in wetland boundary

HYDROLOGYDepth of inundation: in. Primary Indicators: Check if present:Depth to Water Standing in Pit: in. Inundated Sediment Deposits Water MarksDepth to Saturated Soil: <12 in. Saturated Drift Lines Drainage PatternsInundated at hoof prints Secondary Indicators:

Oxidized Root Channels Water-Stained LeavesChannel Banks or OHWM present:Yes No Local Soil Survey Data FAC-Neutral Test

Comments: saturated, slow flowing seep

DETERMINATION:

Hydrophytic Vegetation Criterion Met: Yes NoHydric Soils Criterion Met: Yes No (by 2 indicators)

Hydrology Criterion Met: Yes No

Sample Point Determination:Wetland Non-WetlandWaters of the United StatesWaters of the State Streambeds/Riparian Corridors

Comments: Approx .32 acre

Determined By: R. C. Brody Impact Sciences, Inc.

WETLAND DETERMINATION DATA FORM 1987 ACOE WETLANDS DELINEATION MANUAL

Project Site: Hidden Creeks Sample Plot #: Off-Site – Mormon cyn headw.Applicant: Field Date: 1/25/06Normal Circumstances?: yes Section:Atypical Situation?: no County: L.A.Problem Area?: no State:

VEGETATION: Community Type:Tree Species, Indicator Status, %Cover Grass / Forb Species, Indicator Status, % CoverSalix sp., FACW Juncus sp., OBL, 10-15%

Bulrush (scirpus), OBL, 75-80%Stinging nettleWatercress

Sapling / Shrub Species, Indicator Status, % Cover Woody Vine Species, Indicator Status,Mulefat, FACW, 10% California blackberry

Percent of Dominant Species Classified as OBL, FACW, or FAC: 100%Comments: Greater than 50% of the dominant species are hydrophytic species

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4 in4-8 in8-12 in12-16 inComments: 2 indicators (100% OBL)

HYDROLOGYDepth of inundation: in. Primary Indicators: Check if present:Depth to Water Standing in Pit: in. Inundated Sediment Deposits Water MarksDepth to Saturated Soil: surface >16 in. Saturated Drift Lines Drainage PatternsInundated at hoof prints Secondary Indicators:

Oxidized Root Channels Water-Stained LeavesChannel Banks or OHWM present:Yes No Local Soil Survey Data FAC-Neutral Test

Comments:

DETERMINATION:

Hydrophytic Vegetation Criterion Met: Yes NoHydric Soils Criterion Met: Yes No (by 2 indicators)

Hydrology Criterion Met: Yes No

Sample Point Determination:Wetland Non-WetlandWaters of the United StatesWaters of the State Streambeds/Riparian Corridors

Comments:

Determined By: R. C. Brody/Greg Ainsworth Impact Sciences, Inc.

STREAM DATA FORM GPS Data taken: Yes NoProject / Site: Hidden Creeks Sample Plot # off-site near Mason Ave.Owner/Developer: Field Date: 6/12/06Normal Circumstances? No – downstream construction Lat./Long.:Tributary to: Browns Canyon County: L.A.Adjacent land use: Residential development State: California


Populus fremontii MulefatSalix MugwortPlatanus racemosa Upland:Juglans -laurel sumacOaks, Specify: Valley -coastal sage scrub

Riparian Sapling / Shrub Species Lotus scopariusLeymusBlack sageChaparral yuccaSalvia apianaBrassica nigra

Comments:

SOILS Mapped Series: Hydric Soils List: Yes NoProfile DescriptionDepth: Matrix Color Mottle Abundance and Contrast Texture/structure/concretions0-4”4-8”8-12”12-16Boulders Bedrock ”Gravel or Cobble Sand or Sandy loam Muck, Silt Clay or LoamComments: sorted substrate - signs of bed movement



Yes No ACOE – 12 feet Buffer Continuous for length GradedGroundwater Recharge? Yes , at basin; NoComments:


Stream Width Average: ACOE – 12 feet; CDFG – 20 feet Recent Erosion Evident Yes; NoStream Length (field or map calculation): 770 Feet

Watershed Area: Square MilesComments: Coastal sage communityDetermined By: R.C. Brody Impact Sciences, Inc.

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