**HAZARD MITIGATION GRANT PROGRAM**

## **DOUGLAS COUNTY, WASHINGTON**

**SAND CANYON**

**(Image on Front Cover Not Available in Online Version)**

# **DRAFT ENVIRONMENTAL ASSESSMENT**

**September 22, 2003**

**Federal Emergency Management Agency - Region 10**

**TABLE OF CONTENTS**

Section 1 Introduction

Section 2 Purpose and Need for Project

Section 3 Project Alternatives

Alternative 1 (Preferred Alternative): Construct Seven (7) New
Stormwater Detention Ponds; a New Landslide Buttress Wall; and Remove
Material from the Head of the Badger Mountain Road Landslide.

Alternative 2: Construct Two (2) New Stormwater Detention Ponds and
Remove Material from the Head of the Badger Mountain Road Landslide.

Alternative 3: Do Nothing

Other Alternatives Identified but Dismissed

> Construct a pipe system around the toe of the Badger Mountain Road
> landslide and improve the flow capacity (replace culverts, enlarge the
> channel, remove restrictions, armor) Eastmont Avenue to the Columbia
> River.
>
> Construct cast-in-place concrete buttress walls (instead of gabion
> walls).

Remove the landslide toe.

> Reconstruct the Badger Mountain Road in a new location and remove the
> existing road features.

Section 4 Affected Environment and Environmental Consequences

Floodplain

Water Quality

Wetlands

Geology/Soils

Threatened and Endangered Species

Cultural Resources (Historical/Archaeological)

Socio-Economic Conditions (Environmental Justice -- EO 12898)

Land Use

Safety

Cumulative Impacts

Factors Considered, Not Discussed:

> (Prime Farmlands, Vegetation, Wildlife, Climate & Air, Mineral
> Resources, Utilities, and Noise)

Section 5 Mitigation of Unavoidable Adverse Impacts

Section 6 Public Participation & Agencies Consulted

Section 7 References

Section 8 Appendices:

Maps

Photos

Executive Orders Checklists

Public Involvement

Comments from Agencies

Comments from Public

Draft Engineering Study; Sand Canyon Flood Mitigation Project,

Douglas County, Washington - By: Shannon & Wilson, Inc

Cultural Resources Survey for the Sand Canyon Flood Hazard

Mitigation Project, Douglas County, Washington -- By:

Western Shore Heritage Services, Inc

Sand Canyon Flood Hazard Mitigation FEMA -- Douglas County

Biological Assessment -- By: LeeAnn D. Hancock

Sand Canyon Hazard Mitigation Site Wetland Delineation East

Wenatchee, Washington -- By: ENSR International

**DRAFT**

**ENVIRONMENTAL ASSESSMENT**

**Douglas County -- Sand Canyon**

### FEMA-WA-DR-1361

###### I. INTRODUCTION

Douglas County, Washington (located near the center of the state - See
Appendix -- Maps -- Map #1) applied through the Washington State
Division of Emergency Management to the Federal Emergency Management
Agency (FEMA) for assistance with a Floodway Stabilization Project in
Sand Canyon. FEMA is proposing to fund 75 percent of the cost under the
Hazard Mitigation Grant Program (HMGP) for Presidential Disaster 1361
(Nisqually Earthquake - February of 2001), as authorized in Section 404
of the Robert T. Stafford Disaster Relief and Emergency Assistance Act
(P.L. 93-288, as amended).

FEMA prepared this Environmental Assessment (EA) to evaluate the impacts
of the proposed action according to the requirements of the National
Environmental Policy Act of 1969 (NEPA), the Council on Environmental
Quality (CEQ) regulations implementing NEPA (40 Code of Federal
Regulations \[CFR\] Parts 1500--1508), and FEMA\'s implementing
regulations (44 CFR Part 10). The EA process provides steps and
procedures to evaluate and make informed decisions based upon the
potential environmental impacts of a proposed action as well as an
opportunity for public, local, state, and other federal agencies to
provide input and/or comment through a public comment period.

On February 28, 2001 at a little before noon, a 6.8 magnitude earthquake
struck western Washington State. The Nisqually Earthquake, the largest
to hit Washington State in more than a half a century, caused damage
across much of western Washington. In all, 24 counties and 25 Indian
Reservations were included in the Presidential Disaster Declaration
issued on March 1, 2001 by President Bush. Douglas County sustained
damages to public facilities totaling about \$20,000. Douglas County is
located about 120 miles east of the epicenter of the Nisqually
Earthquake.

**II. PURPOSE AND NEED FOR THE PROJECT:**

Douglas County and the city of East Wenatchee have experienced flash
flooding and landslides in Sand Canyon, located east of East Wenatchee.
Flash floods in the Sand Canyon channel create erosion, sedimentation,
and flooding problems. Past flooding resulted in private property
damage, accelerated movement of existing landslide areas, and damaged
roads, roadside ditches, and embankments. The landslide of particular
concern is "The Badger Mountain Road Slide" near the mouth of Sand
Canyon. The Badger Mountain Road traverses the upper portion of the
slide. The Sand Canyon channel is located at the toe of the Badger
Mountain Road Slide and high flows in the channel exacerbate the problem
by eroding the toe and removing any buttress effect.

The purpose of FEMA's HMGP is to reduce the potential loss of life and
property due to natural disasters and to enable long-term hazard
mitigation measures to be implemented during the immediate recovery from
a disaster. Through this program, FEMA provides grants to states, local
governments, tribal governments, and U.S. territories to implement
hazard mitigation projects after the declaration of a major disaster.
The purpose of this project is to provide funding for Douglas County to
implement a cost-effective hazard mitigation project to address flooding
and landslides.

The need for this project is to reduce flood damage (inundation,
erosion, & sedimentation) to Douglas County and East Wenatchee and to
stabilize the landslide area below Badger Mountain Road. The flood
damage reduction features will reduce the impacts of flooding to public
and private property. The landslide stability features will reduce the
potential for catastrophic slope failure.

Douglas County has identified the following project goals:

-   Decrease risk of injury or loss of life due to overtopping and/or
    washout of roads within the Sand Canyon Basin.

-   Decrease maintenance costs of cleaning sediment-laden culverts and
    waterways.

-   Reduce the negative impact that sediment-laden floodwater discharge
    has to downstream fish habitat within Sand Canyon and Columbia
    River.

-   Decrease the potential for damage to downstream properties resulting
    from inadequate floodways and un-detained floodwater.

-   Reduce maintenance costs of Badger Road due to the accelerated slide
    movement at the toe of the slope within upper Sand Canyon.

-   Decrease the risk of injury or loss of life due to catastrophic
    failure of the Badger Mountain Road landslide.

-   Maintain access to residents of the Fancher Heights housing
    development via Badger Mountain Road and to ensure the availability
    of emergency services.

**III. PROJECT ALTERNATIVES:**

Alternatives evaluated in this environmental assessment were selected by
the applicant to reduce the need for further disaster assistance and
eliminate repetitive damage during future disaster events (i.e.
earthquake and/or flood).

**Alternative I (Preferred Alternative): Construct Seven (7) New
Stormwater Detention Ponds; a New Landslide Buttress Wall; and Remove
Material from the Head of the Badger Mountain Road Landslide (See
Appendix -- Maps -- Map #2 and Appendix -- Photos - All).**

This alternative consists of three major components: 1) construct seven
(7) stormwater detention ponds in the Sand Canyon channel to temporarily
store excess floodwater and release it at a slower rate, 2) construct a
1150 foot gabion basket landslide toe buttress in the bottom of Sand
Canyon to stabilize the landslides and reduce the toe erosion, and 3)
remove material from the head of the Badger Mountain Road landside to
decrease the mass pushing the slide downhill. The work associated with
each component will be done during the dry season (from late Spring to
early Fall) to reduce the potential for rainfall and water flows causing
construction site erosion and flows damaging the construction zones.

[Construct seven (7) stormwater detention ponds:]{.underline} The ponds
will be simple low head (4.6' to 14') earth fill "run of the stream"
dams (A simple dam with a pipe at the bottom of the dam; normal flows
pass through the dam without creating a pond. As flows increase and
exceed the capacity of the pipe, excess water is detained creating a
pond. Then as the flow decreases the excess water is released draining
the pond.). The dams will be designed to use existing native materials,
providing some intentional leakage through the dam. The dams will have
manholes (outlet control devices), armored emergency spillways, outlet
energy dissipaters, and roads across the crest. (See Appendix -- Draft
Engineering Study by Shannon & Wilson). Property owners (farmers) will
have the ability to use some of the roads across the top of the dams as
access roads between fields.

The ponds are located to capture floodwaters from smaller areas (sub
catchments). They are strategically located throughout the basin to
maximize their effectiveness in controlling the discharge to a more
manageable flow in lower Sand Canyon. The objective is to level out the
peak flows so the existing downstream drainage facilities can handle the
volume. The ponds will be located on private property, which the County
will negotiate with the property owners for access, construction,
operations, and maintenance rights.

The basic design, construction method and sequence, and erosion/sediment
control BMPs will be same for all seven (7) detention ponds. The storage
capacity, dam length & height (embankment volume), outlet pipe length &
diameter, and maximum water depth will vary for each pond based on site
conditions, expected flow, and storage volume required. The construction
sequence will generally be as follows:

1.  Installation of erosion/sediment control BMPs.

2.  Clear and grub the embankment footprint (this material will be
    permanently stockpiled on-site).

3.  Excavate a cut-off trench (3 foot deep or to solid rock).

4.  Moisture treat and compact the cut-off trench \[the transition
    between the cut-off trench and embankment fill will be continuous
    (without seams or joints)\].

5.  Install the outlet energy dissipater.

6.  Bed & place the outlet pipe and inlet catch basin.

7.  Place and compact the embankment (source of embankment material will
    be the existing native materials in the pond storage area) creating
    a dam top width of 12 feet and side slopes of 2 horizontal to 1
    vertical.

8.  Construct an emergency overflow spillway over the dam.

9.  Install permanent wind/water erosion protection (native vegetation
    or course aggregate) on the embankment slopes and top.

10. Spread (hydroseed preferred) a seed mixture (blended for the area)
    over all exposed surfaces.

11. Provide surface treatment for the access roads and top of embankment
    compatible with anticipated traffic and erosion potential.

12. Remove erosion/sediment control BMPs (if required).

All materials and construction methods/techniques will be in accordance
with Washington State Department of Transportation and American Public
Works Association standard specifications for road, bridge, and
municipal construction.

Douglas County will monitor, operate, and maintain the detention ponds.
Maintenance monitoring will be done on a random basis throughout the
year (about 12 times per year) to determine cleaning, operational, and
maintenance needs of each pond. This monitoring will include checking:
the dam's access road, tops & side slopes (embankment & native) for
erosion, settlement, displacement, sloughing, piping, burrowing,
vegetation survival, presence of invasive (non-native) species, and
debris accumulations; inlet structures, pipes, and energy dissipater for
settlement, displacement, structural integrity and debris; and the pond
storage area for sink holes, and debris & sediment accumulations.

The results of the maintenance monitoring will be used to develop the
maintenance work orders. Maintenance work (including material disposal)
will be done in accordance with Douglas County Maintenance Standards.
Performance monitoring will be done during storm/flood events to
determine emergency operations/maintenance needs, ensure the detention
ponds are functioning properly, and to design adjustments to maximize
effectiveness. Observations of rainfall, snowmelt, inlet flow, outlet
flow, and pond depth will be recorded and reported to the surface water
management unit for proper evaluation and adjustments.

[Construct a landslide toe buttress in the bottom of Sand
Canyon:]{.underline} The buttress will accomplish three goals: 1)
improve stability of the slide by creating a stable mass that will
resist movement of the slide, 2) create a stable stream flow channel for
part of the Sand Canyon channel, and 3) reestablish vegetation in the
newly constructed gabion channel by using some soil particles to fill
the gabion baskets and planting native species.

The buttress will be a rock filled gabion (wire mesh filled with
granular/soil mix) basket structure at the base of the Badger Mountain
Road landslide in the bottom of Sand Canyon. The buttress will be about
1150 feet long. The outlet end of the buttress will be located about ½
mile east (up channel) of Eastmont Avenue.

The cross section of the gabion buttress resembles a "U" or flat
bottomed horseshoe. The bottom slope of the channel will vary to match
the existing slope. The channel width between the walls will vary from 4
feet to 12 feet. The height of the walls will vary from 10 feet to 14
feet depending on the top catch point. The bottom tier of the wall
gabions will be 6 feet wide and 3 feet high. The gabions will get
progressively narrower as they are stacked (See Appendix -- Draft
Engineering Study by Shannon & Wilson). The gabions will be filled with
granular material and soil mix. The soil mix is intended to support
vegetation growth.

The construction will be done in small increments to minimize any impact
to the stability of the landslide. The work will start at the lower end
of the project and proceed up channel. The general construction sequence
is anticipated to be:

1.  Construct an access road along the north side of the channel
    (traversing the slide area). The access road will remain for
    long-term monitoring and maintenance.

2.  Install erosion/sediment control BMPs.

3.  Cut and remove portions of old abandoned (approximate 2-inch
    diameter) pipe.

4.  Install flow diversion/by-pass system around work zone.

5.  Clear, grub, and shape the channel (this material will be hauled to
    a County approve disposal facility or used as fill material in the
    gabions - if suitable).

6.  Install the gabion base.

7.  Fill the gabions with material/mix.

8.  Close and tie the gabions.

9.  Install and fill the wall gabions.

10. Plant native vegetation.

11. Remove flow diversion/by-pass and allow flow in newly constructed
    buttress channel.

12. Remove erosion/sediment control BMPs (if required).

All materials and construction methods/techniques will be in accordance
with Washington State Department of Transportation and American Public
Works Association standard specifications for road, bridge, and
municipal construction.

Douglas County will be responsible for monitoring, operating, and
maintaining the buttress wall. Maintenance monitoring will be done on a
random basis throughout the year (about 12 times per year) to determine
cleaning, operational, and maintenance needs. This monitoring will
include checking: the landslide areas for signs of movement (this may
require establishment of survey monuments); gabion baskets and quarry
spalls for displacement, wire breakage, and/or material removal; piping
of landslide material; sloughing; vegetation survival; presence of
invasive (non-native) species; and debris accumulations. The results of
the maintenance monitoring will be used to develop the maintenance work
orders. Maintenance work (including material disposal) will be done in
accordance with Douglas County Maintenance Standards. Performance
monitoring will be done during storm/flood events to determine emergency
operations/maintenance needs.

[Remove material from head of Badger Mountain Road
landslide:]{.underline} Remove about 66,000 tons (43,500 cubic yards) of
material from the head of the Badger Mountain Road landslide to reduce
the mass pushing the slide downhill. The area of excavation will be
uphill of the Badger Mountain Road. The construction sequence will
generally be as follows:

1.  Define, survey, and stake the removal area.

2.  Install erosion/sediment/pollution control BMPs.

3.  Use small equipment to start the removal process (avoid additional
    loading of the slide).

4.  Follow County guidelines/criteria regarding pit operations, access
    and use of County roads.

5.  Haul the material to a County permitted (non-environmentally
    sensitive) disposal site.

6.  Grade the area to direct runoff from the slide plane and avoid
    surface water collection.

7.  Revegetate all disturbed areas with native species.

8.  Install final/permanent erosion/sediment control features.

Douglas County will monitor and maintain the material removal area.
Maintenance monitoring will be done on a random basis throughout the
year to determine maintenance needs. This monitoring will include
checking the area for signs of movement (this may require establishment
of survey monuments), vegetation survival, presence of invasive
(non-native) species, and debris accumulations. The results of the
maintenance monitoring will be used to develop the maintenance work
orders. Maintenance work (including material disposal) will be done in
accordance with Douglas County Maintenance Standards.

**Alternative II: Construct Two (2) New Stormwater Detention Ponds and
Remove Material from the Head of the Badger Mountain Road Landslide (See
Appendix -- Maps -- Map #2 and Appendix -- Photos -- 2 &3).**

##### 

This alternative consists of constructing two (2) stormwater detention
ponds in the Sand Canyon channel to temporarily store excess floodwater
and release it at a slower rate and remove material from the head of the
Badger Mountain Road landside to decrease the mass pushing the slide
downhill. The work associated with each component will be done during
the dry season (from late Spring to early Fall) to reduce the potential
for rainfall and water flows causing construction site erosion and flows
damaging the construction zones. The Pond and Material Removal Area
locations correspond to Ponds 1 & 2 and the Material Removal Area
outlined in Alternative I.

The results of the hydraulic analysis for the two ponds will create a
system that will limit the discharge so the capacity of the downstream
culverts during a 100-year event is not exceeded. The basic design,
construction methods/sequence, erosion/sediment control BMPs, and
monitoring, operation, and maintenance program for the detention ponds
and material removal will be the same as outlined in Alternative I.

##### Alternative III: The No-Action Alternative 

Under the No-Action Alternative, the County would not pursue flood
reduction or landslide stabilization projects for Sand Canyon. Douglas
County and East Wenatchee would continue their current flood response
programs; react to the situations presented (place water over roadway
signs, close roads, repair/rebuild roads and drainage systems, and
clean-up debris and sediment). Private property owners would be
responsible for their own activities. Douglas County would continue to
monitor the differential settlement along Badger Mountain Road and add
asphalt to smooth the bumps. In the event of a large disaster there
would most likely be a request for state or federal assistance.

##### Other Related Project -- Not Part of the HMGP Project

The County is in the process of developing and implementing plans for
their Capital Improvement Project (identified in their 6-Year Plan) to
upgrade Badger Mountain Road (expected construction 2005) from the
intersection of Nineteenth Street Northeast and Eastmont Avenue to the
intersection of Badger Mountain Road and Fancher Field Road (aka Gun
Club Road). The road improvements include (but not limited to):
drainage, slow vehicle lane, bicycle lane, turning lanes, lighted
intersections, and guard rails. The drainage features are designed to
intercept the surface drainage and convey it away from the head of the
Badger Mountain Road slide area.

##### Other Alternatives Identified but Dismissed:

Douglas County considered and analyzed several other alternatives to
meet their needs (reduce flood damage and stabilize the landslide areas)
but dismissed these alternatives based on several factors. The factors
considered for each alternative included cost, liability and safety,
property availability, meets needs, community acceptability, technical
issues, impact to environmentally sensitive areas, constructability, and
maintainability.

[]{.mark}

The alternatives considered and corresponding reasons for dismissal are
outlined:

-   Construct a pipe system around the toe of the Badger Mountain Road
    landslide and improve the flow capacity (replace culverts, enlarge
    the channel, remove restrictions, armor) Eastmont Avenue to the
    Columbia River. The County determined this alternative would: be
    very difficult and expensive to construct, require deleting the in
    channel wetlands, and meet community opposition as the residents
    along the existing channel would be reluctant to see their property
    changed to accommodate "engineered" channel improvements.

-   Construct cast-in-place concrete buttress walls (instead of gabion
    walls). The County determined this alternative would: be very costly
    and difficult to construct, result in a rigid structure in an
    unstable area which can develop some unique and difficult
    maintenance and repair problems, and delete the in channel wetlands.

-   Remove the landslide toe. The County determined this alternative
    would exacerbate the landslide stability problem.

-   Reconstruct the Badger Mountain Road in a new location and remove
    the existing road features. The County determined this alternative
    would be very costly, difficult to find a route without severe
    engineering and environmental problems, public controversy with
    property owners reluctant to have a new major road in the
    neighborhood, not solve the existing flooding problem, and require
    new property negotiations.

**IV. AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES:**

Douglas County is located near the geographic center of the State of
Washington. The County is bound on the north and west by the Columbia
River, the east by Grand Coulee and Lincoln County and the south by the
Columbia River and Grant County. The City of Waterville, located near
the center of the County, is the county seat. The most populated City,
East Wenatchee, is located in the southwest portion of the County at the
outlet of Sand Canyon.

Eastmont Avenue, originating in East Wenatchee, basically becomes Badger
Mountain Road as it turns east and starts uphill. The Badger Mountain
Road provides the only direct access between East Wenatchee and Fancher
Heights/North Plateau (a residential development consisting of about 230
single family residences and additional approved residential lots),
agricultural land, a racetrack and gun club, and the Farm to Market
access road between Waterville and East Wenatchee.

Due to the geographic diversity, the climate in the Sand Canyon drainage
basin varies. Winters are generally cold (average minimum January
temperatures 15 to 21 degrees Fahrenheit) and summers are hot (average
maximum July Temperature 82 to 88 degrees Fahrenheit). Average annual
precipitation in the drainage basin is about 9 inches. The average
annual snowfall is about 43 inches on the ridge and about 30 inches near
the Columbia River.

##### [Floodplain]{.underline}

*Affected Environment:*

The drainage basin for Sand Canyon (about 5.5 miles long -- east to west
and up to 1 mile wide -- north/south) drains about 2900 acres (See
Appendix -- Maps -- Map #1). It originates on a high ridge (elevation
3300' MSL) in the east and drops to the Columbia River (elevation 600'
MSL) in the west. The main channel (ephemeral and intermittent flow)
associated with Sand Canyon traverses four distinct profiles (sections)
as it originates in the east:

-   Section 1 is very steep (about 25 to 40%) and characterized by sheet
    flow and steep rivulets as the drainage basin descends the ridge and
    collects into channels. This section is referred to as the
    headwaters.

-   Section 2 is a gradual slope (about 3 to 5%) and characterized by a
    meandering incision (about 25 to 50 feet deep). This section is
    referred to as the upland channel(s).

-   Section 3 is steeper (about 7.5%) and characterized by a deep
    incision (about 200 feet deep; often to bedrock). The bottom of the
    incision is vegetated with trees and brush while the side slopes of
    the incision have sparse native grasses and sagebrush. This section
    is referred to as Sand Canyon.

-   Section 4 is flatter (about 4.5%) and is part of the alluvial fan
    from Sand Canyon. Its characteristics are typical of urban streams
    in arid environments (culverts, some vegetation, man-made erosion
    control structures, etc) as it flows through orchards, residential,
    commercial, and park areas from about ¼ mile east of Eastmont Avenue
    to its confluence with the Columbia River. This section is referred
    to as Sand Canyon Creek.

The 100-year floodplain associated with The Sand Canyon and Sand Canyon
Creek has been mapped as an AO zone on the Flood Insurance Rate Map. The
mapped portion of the floodplain ends about ¾ mile east (up channel) of
Eastmont Avenue. The AO zone is an area of shallow flooding. At the
mouth of the canyon the flooding spreads out in an alluvial floodplain
typically associated with flash flooding type events in arid
environments. Flash flooding occurs when high intensity rainfall
combines with snowmelt and frozen ground. Due to topography, flooding is
confined to the existing channel from the headwaters to the mouth of
Sand Canyon (about ¼ mile east up channel of Eastmont Avenue).

There is evidence (numerous small dry channels meandering through recent
sediment deposits) of an active alluvial from the mouth of Sand Canyon
to Eastmont Avenue. The whole floodplain in this section comprises of
open space and agricultural use. No structures are within the
floodplain.

The alluvial fan is inactive from Eastmont Avenue to the Columbia River
because the urban development has confined normal flood flows to a
channel and culverts. The identified 100-year floodplain is fairly
narrow (about 25 to 100 feet) along both sides of Sand Canyon Creek.
Flooding is caused because the 100-year flood exceeds the capacity of
the road culverts and the channel (resulting in road overtopping,
backwater effects and overbank flows). Due to the urban nature, some
structures are within the floodplain or are susceptible to flooding from
the backwater effects.

Both Douglas County and East Wenatchee are participating members with
"good standing" in the National Flood Insurance Program. They both
enforce ordinances regulating development in the floodplain.

*Environment Consequences:*

**[Alternative I]{.underline}:** This alternative will flatten the
hydrograph of larger flow events (reduce the peak and increase the
duration) down channel of the ponds. The total volume of water flowing
in the channel will remain about the same. There may be a small
reduction in the total volume due to infiltration in the pond area as
the water is detained in the detention ponds. According to the hydraulic
analysis conducted by Shannon and Wilson, Inc., the 100-year flood flow
will be confined to existing culverts and channels from Eastmont Avenue
to the Columbia River. The anticipated pre and post project 100-year
flows are outlined in Table 1. The hydrograph of normal low flow events
will not be changed. The water will flow through the pond pipes without
being detained.

+-------------+-------------+-------------+-------------+-------------+
| **Pond      | **Drainage  | **Existing  | **With      | **Maximum   |
| Number      | Basin**     | C           | Detention   | Storage     |
| (Proceeding |             | onditions** | Ponds**     | Required**  |
| Down        | **(Acres)** |             |             |             |
| Channel)**  |             | **100-Year  | **100-Year  | **(A        |
|             |             | Flow**      | Flow**      | cre-Feet)** |
|             |             |             |             |             |
|             |             | **(CFS)**   | **(CFS)**   |             |
+-------------+-------------+-------------+-------------+-------------+
| **5**       | 506         | 134         | 24          | 9.8         |
+-------------+-------------+-------------+-------------+-------------+
| **4**       | 949         | 299         | 31          | 12.5        |
+-------------+-------------+-------------+-------------+-------------+
| **3**       | 1274        | 410         | 42          | 18.2        |
+-------------+-------------+-------------+-------------+-------------+
| **6**       | 563         | 291         | 16          | 31.9        |
+-------------+-------------+-------------+-------------+-------------+
| **2**       | 1874        | 787         | 61          | 5.4         |
+-------------+-------------+-------------+-------------+-------------+
| **7**       | 59          | 27          | 9           | 0.8         |
+-------------+-------------+-------------+-------------+-------------+
| **1**       | 2213        | 927         | 112.3       | 4.7         |
+-------------+-------------+-------------+-------------+-------------+

### Table 1: Peak Flow (100-Yr.) Reduction with Detention

The potential short-term (construction period) impacts include:

-   Increased turbidity/sediment load of flood waters (caused by erosion
    of exposed soils in the construction zones) and increased pollution
    (from accidental spills and/or "wash-off" from poorly maintained
    equipment or vehicles). The County will implement and maintain Best
    Management Practices (Washington State Department Of Transportation
    -- Construction Practices Guidelines or similar guidelines) to
    mitigate these impacts.

-   Construction disruption due to rainfall and surface water flows. The
    County will limit the construction period as much as possible to the
    dry season (from late Spring to early Fall), along with implementing
    and maintaining good Best Management Practices to mitigate these
    impacts.

-   Flood damage during construction. The County will install flow
    by-pass features, and limit the construction period as much as
    possible to the dry season (from late Spring to early Fall) to
    mitigate these impacts.

The potential long-term impacts include:

-   Flattening (reduce the peak and increase the duration) of the
    hydrograph for larger flow events below the ponds;

-   Passing greater than the 100-year flow through the existing culverts
    and channel without overtopping, backwater, or flooding; and

-   Changing the floodplain values and/or functions of Sand Canyon. The
    floodplain values/functions impacted are:

    -   Infiltration: The floodplain infiltration area for the channel
        will be reduced, but increased in the detention ponds. The time
        available for the water in the channel to infiltrate will be
        increased due to the longer flow caused by the detention ponds.

    -   Flood storage: The flood storage area will be increased due to
        the pond construction resulting in reduced potential for damages
        to structures down channel of Eastmont Avenue.

    -   Deposition of suspended materials: The amount of suspended
        sediments will be reduced in correlation to reduced flow,
        deposition at the detention ponds, and stabilization of the
        landslide toe. This will reduce the potential for blockage at
        culverts. It will also reduce the natural deposition area of the
        Sand Canyon alluvial fan (which has been impacted by
        development).

    -   Nutrient replacement: With decreased flow rate, nutrient removal
        and replacement will be reduced during high flow events.

    -   Wildlife habitat and food: With lower flows (during 100-year
        events), the potential for erosion of the riparian habitat (both
        natural and artificial landscape) will be reduced. The longer
        flow period may promote additional vegetation along the riparian
        edge and around the detention ponds. However, a reduction in
        some plant species dependent upon catastrophic events may occur.

Implementation of the best management practices and other measures
identified above satisfy the requirements of Executive Order 11988,
Floodplain Management. See Appendix -- Executive Orders Checklists --
Floodplain) for evaluation under the 8 Step process.

**[Alternative II]{.underline}**: The impacts will be similar to those
outlined in Alternative I, but concentrated in only two areas. However,
some differences will occur. Since only two ponds will be constructed,
the size of inundation will be larger per pond. The overall wetted edge
will be less than in Alternative I resulting in less potential for
habitat formation. The hydrograph will be flattened and the flow
capacity of the channel/ culverts in Sand Canyon Creek will be limited
to the 100-year flood event. The landslide toe will erode at a higher
rate than expected in Alternative I. Deposition of sediment at Pond 1
due to input from the landslide area will require more frequent removal
in order to maintain detention capacity.

**[Alternative III]{.underline}**: There would be no change to current
impacts. Flooding in the upper reaches of the drainage basin will be
confined to the channel. From the mouth of Sand Canyon to the Columbia
River culvert and channel capacity will be exceeded resulting in road
overtopping, road embankment erosion and overbank flooding. Property and
structures abutting Sand Canyon Creek will continue to be impacted and
damaged.

##### [Water Quality]{.underline}

*Affected Environment:*

The Sand Canyon drainage basin contributes water through Sand Canyon
Creek to the Columbia River. The stormwater detention ponds, connecting
channels, wetlands, the buttress wall, floodplain, Sand Canyon Creek,
and the Columbia River have the potential to affect or be affected. The
land uses outlined above have the potential to impact water quality as
follows:

-   Agriculture -- soil particles through the farming and erosion
    process; herbicides and pesticides; and animal wastes.

-   Geologically Hazardous Area and Native Open Space - soil particles
    through the erosion and/or landslide process.

-   Urban/Residential - herbicides and pesticides; animal wastes, street
    runoff pollutants, and vegetation waste.

*Environment Consequences:*

Alternate I & II:

The potential short-term impacts include increased turbidity and
sediment load as a result of construction site erosion (water and wind)
and an increased pollutant load as a result of accidental construction
spills. Implementing and maintaining good Best Management Practices and
construction sequencing can mitigate these impacts.

The potential long-term impacts include a reduction in turbidity and
sediment and pollutant loads in the drainage features (ponds, channel,
floodplain, and River) down channel of the stormwater detention ponds as
a result of particulate settling. The sediment accumulations in the pond
areas should be analyzed to determine the appropriate removal and
disposal techniques.

Alternate III:

There would be no changes to the current impacts. Soil particles and
pollutants will still be transported down channel. These will continue
to be deposited in the alluvial fan section, the creek floodplain and
channel, and the Columbia River.

##### [Wetlands]{.underline}

*Affected Environment:*

A Wetland Delineation was completed by ENSR International. The wetland
delineation was conducted continuously along Sand Canyon from the
proposed location of Detention Pond 1 to the proposed location of
Detention Pond 3 under Alternative I. Additionally, the proposed
locations for Ponds 4 through 7 were also surveyed for wetland habitat.
This delineation would also cover the Pond locations under Alternative
II.

According to the Wetland Delineation Report, about 2.5 acres of wetland
habitat, containing three individual wetland communities (WL01, WL02,
and WL03) were surveyed within the Sand Canyon project area (See
Appendix -- Sand Canyon Hazard Mitigation Site Wetland Determination).
All identified wetlands were within Sand Canyon (Section 3), and all
wetland community types surveyed belonged to the Palustrine System. Each
community was dominated by trees, shrubs, or persistent emergents; at
less than 20 acres; water depth was less than 6.6 feet, and salinity was
less than 0.5 parts per thousand.

Wetland 01 is a Palustrine Scrub-Shrub Wetland oriented from northeast
to southwest and located approximately 700 feet up channel from the
proposed location of detention pond 2. This wetland is about 800 feet in
length along the channel of Sand Canyon. It is composed primarily of
willow, western crabapple, field horsetail, mountain alder, common
cat-tail, stinging nettle, reed canarygrass, red-osier dogwood, black
cottonwood, and scouring horsetail. This wetland community is saturated
to the surface, with areas of surface inundation in the stream channel
observed during the field surveys.

Wetland 02 is a Palustrine Forested Wetland located along the southeast
bank of Sand Canyon, approximately 150 feet southwest (down channel) of
Wetland 01. It is about 100 feet long and dominated by black cottonwood,
willow, and scouring horsetail. At the time of the surveys, this wetland
community was saturated within the rooting zone.

Wetland 03 is a Palustrine Forested Wetland located along the channel of
Sand Canyon approximately 75 feet southwest (down channel) of Wetland
02. Detention pond 2 will be located near the uppermost section. This
wetland is approximately 1800 feet long dominated by black cottonwood,
willow, scouring horsetail, common cat-tail, smartweed, duckweed, water
speedwell, and smooth sumac. A pipe coming out of the northwest bank of
the channel at the northeast end of the wetland provided a continuous
supply of water feeding into the wetland. The USGS Wenatchee Quadrangle
map indicates a spring in this area. This wetland follows the channel
width, widening and narrowing as the channel widens and narrows. This
wetland community was flooded within the channel (2 and 16 inches) and
saturated to the surface along the banks.

*Environment Consequences:*

[Alternative I]{.underline}:

Wetland 01 will remain as is and not be negatively impacted by the
project. Although detention ponds will be built up-channel of the
wetland, the flow regime sustaining the wetland would not change.

Wetland 02 will be inundated during flood events by detention pond 2
until the water level recedes. Some temporary impacts will occur during
these events, with potential for long-term impacts on the vegetative
composition. Due to the lower flow rate emanating from detention pond 3,
the potential for catastrophic events (such as erosion from high flow)
impacting the wetland will be reduced

Wetland 03 will be partially (lower portion) obliterated by the
construction of the buttress wall. The upper portion (pipe outlet) would
not be impacted. However, it will be temporarily inundated by detention
pond 2 during high flow events. Some of the wetland vegetation destroyed
by the construction of the gabion buttress may reestablish due to the
continuous water supply, soil material being placed in the gabion
baskets, and planting selected vegetation in the base gabions. Other
impacts for the upper portion will be the same as for Wetland 02.

The applicant will obtain the necessary 404/401 "Wetland" permit from
the U.S. Corps of Engineers, as required by the Clean Water Act.
Additional requirements to minimize impacts will be identified through
this permit process. Implementing of these measures will also satisfy
the requirements of Executive Order 11990, Protection of Wetlands.

[Alternative II]{.underline}: The upper portion of Wetland 03, all of
Wetland 02 and possibly the lower portion of Wetland 01 will be
temporarily inundated by detention pond 2 during high flow events. The
impacts would be similar to Alternative I but on a larger scale.
Additional wetlands may be created due to the larger wetted edge of
detention pond 2.

[Alternative III]{.underline}: The wetlands will continue to exist in
their current state. During high flow events, portions of all three
wetlands may be destroyed or degraded due to erosion or mass wasting.

**[Geology and Soils:]{.underline}**

*Affected Environment:*

The geology of Douglas County in the project area varies considerably.
The following formations are found:

1.  continental sedimentary deposits or rocks - Miocene, middle to
    upper,

2.  Grande Ronde Basalt flows - Miocene, middle,

3.  loess - Holocene-Pleistocene,

4.  mass-wasting deposits, mostly landslides - Holocene-Pleistocene,

5.  Frenchman Springs Member Basalt flow - Miocene, middle,

6.  outburst flood deposits, sand, silt and gravel, late Wisconsin --
    Pleistocene,

7.  dune sand -- Holocene,

8.  talus deposits - Holocene-Pleistocene,

9.  alluvium - Holocene-Pleistocene,

10. alluvial fan deposits - Holocene-Pleistocene.

The soils of Douglas County formed in material weathered from glacial
till and outwash, loess, volcanic ash and pumice, basalt, granite,
sedimentary and metamorphic rocks, alluvium, eolian sand, and lake
sediment. Soils that formed in alluvium occur mostly on terraces and
flood plains along the Columbia River and in the bottoms of streams and
valleys.

The project area consists of four soil map units. They are (in order of
decreasing abundance): Xerothents (very steep); Chelan very fine sandy
loam, gravelly substratum (0 to 8 percent slopes);
Ralls-Renslow-Bakeoven association (steep); and Renslow-Zen association
(undulating). Additional information about these soils can be found in
the Wetland Delineation Report prepared by ENSR International.

Douglas County designated Sand Canyon a "Geologically Hazardous Area"
because it contains several landslides on both the north and south side
slopes. The large landslide on the north slope of the canyon is of
particular concern. This slide is located on the north side of Sand
Canyon, the toe of the slide being in the channel near the mouth of the
canyon and the head above Badger Mountain Road. Badger Mountain Road
traverses a portion of the slide. Evidence of the slide (distinct bumps)
can be seen on the road surface.

The Badger Mountain landslide is a deep rotational slide, but the
movement also includes a clockwise rotation about the west-end of the
slide. The soil profile is comprised of sandy silt overlying basalt.
Below the basalt, layers of sandstone, upper claystone, and lower
siltstone/claystone of the Wenatchee Formation are encountered. The
slide plane is located within the Wenatchee Formation and is coincident
with the groundwater surface.

The slide results from loss of shear strength in the Wenatchee
Formation, which is exacerbated by infiltration of surface water from
the head scarp and drainage culvert under Badger Mountain Road. The
slide stability is further compromised by mass wasting at the toe, which
results from erosion in Sand Canyon.

According to the "Uniform Building Code Seismic Zone Map of the
Contiguous United States" (downloaded 4/11/2002), the City of East
Wenatchee is located in Seismic Zone 2B. This indicates new buildings
must implement the "moderate" Construction Standards to meet "Code".

*Environment Consequences:*

[Alternative I]{.underline}:

The potential short-term impacts would be:

-   Construction site erosion and down channel sedimentation during
    rainfall events.

-   Wind blown dust as a result of wind across exposed surfaces.

-   Landslide movement.

Implementing and maintaining good Best Management Practice and
construction sequencing can mitigate these impacts.

The potential long-term impacts include:

-   Collection of sediment in the ponds as a result of farm field
    erosion; natural up channel incision and bank erosion; and wind
    blown dust. The ponds will require periodic monitoring and sediment
    removal/disposal.

-   Decrease in the rate of channel incision and bank erosion in the
    channels down channel of the ponds.

-   Increased stability of the landslides in Sand Canyon (resulting in
    decreased Badger Mountain Road maintenance costs and decreased
    probability of catastrophic slide).

-   Decrease in the amount of overbank soil deposition in the developed
    alluvial fan section.

[Alternative II]{.underline}:

The potential short-term impacts would be:

-   Construction site erosion and down channel sedimentation during
    rainfall events.

-   Wind blown dust as a result of wind across exposed surfaces.

Implementing and maintaining good Best Management Practice and
construction sequencing can mitigate these impacts.

The potential long-term impacts include:

-   Collection of sediment in the ponds as a result of farm field
    erosion; natural up channel incision and bank erosion; landslide toe
    erosion; and wind blown dust. The ponds will require periodic
    monitoring and sediment removal/disposal.

-   Decrease in the rate of channel incision and bank erosion in the
    channels down channel of the ponds.

-   The rate of channel incision and bank erosion up channel of Pond 2
    will remain the same.

-   Decrease in the amount of overbank soil deposition in the developed
    alluvial fan section.

-   The slide stability problems will be reduced except during large
    flood events, which cause toe erosion of the slide area.

[Alternative III]{.underline}:

There would be no change in current impacts. The channel will continue
to experience incision and bank erosion. The landslides in Sand Canyon
will suffer the same slide stability problems (toe erosion, Badger
Mountain Road repair, probability of catastrophic event). Overbank soil
deposition in the developed alluvial fan section can be expected during
flood events.

##### [Threatened And Endangered Species]{.underline}

LeeAnn Hancock, Washington State Department of Transportation Wildlife
Biologist prepared a Biological Assessment (BA) for Alternative 1. Based
upon the BA, FEMA determined that there would be no effect on listed
species, critical habitat and no adverse effect on essential fish
habitat. Although not evaluated in the BA, the determination of effect
for Alternative 2 would be same as Alternative 1. Alternative 3 would
have no effect for all species. Table 2 summarizes the BA's
determination of effect.

## *USFWS Species []{.mark}*

[]{.mark}

+-----------------------+----------------------+------------+----------+
| [Common name]{.mark}  | [Scientific          | [Federal   | [Effect  |
|                       | Name]{.mark}         | Stat       | Call     |
|                       |                      | us]{.mark} | ]{.mark} |
|                       |                      |            |          |
|                       |                      | []{.mark}  | [        |
|                       |                      |            | ]{.mark} |
+-----------------------+----------------------+------------+----------+
| Pygmy Rabbit          | *Brachylagus         | Endangered | NE       |
|                       | idahoensis*          |            |          |
+-----------------------+----------------------+------------+----------+
| Bald Eagle            | *Haliaeetus          | Threatened | NE       |
|                       | leucocephalus*       |            |          |
+-----------------------+----------------------+------------+----------+
| Bull Trout            | *Salvelinus          | Threatened | NE       |
|                       | confluentus*         |            |          |
+-----------------------+----------------------+------------+----------+
| Critical Habitat for  | *N/A*                | Proposed   | NE       |
| Bull Trout            |                      |            |          |
+-----------------------+----------------------+------------+----------+
| Ute ladies'-tresses   | *Spiranthes          | Threatened | NE       |
|                       | diluvialis*          |            |          |
+-----------------------+----------------------+------------+----------+
| Washington ground     | *Spermophilus        | Candidate  | NE       |
| squirrel              | washingtoni*         |            |          |
+-----------------------+----------------------+------------+----------+
| Western sage grouse   | *Centrocercus        | Candidate  | NE       |
|                       | urophasianus phaios* |            |          |
+-----------------------+----------------------+------------+----------+
| Western burrowing owl | *Athene cunicularia  | Species of | NAE      |
|                       | hypugea*             | Concern    |          |
+-----------------------+----------------------+------------+----------+

## *NOAA-Fisheries Species*

+--------------------+----------------------+-------------+-----------+
| [Common            | [Scientific          | [Federal    | [Effect   |
| name]{.mark}       | Name]{.mark}         | Sta         | Cal       |
|                    |                      | tus]{.mark} | l]{.mark} |
|                    |                      |             |           |
|                    |                      | []{.mark}   | []{.mark} |
+--------------------+----------------------+-------------+-----------+
| Upper Columbia     | *Oncorhynchus        | Endangered  | NE        |
| River Steelhead    | mykiss*              |             |           |
| Trout              |                      |             |           |
+--------------------+----------------------+-------------+-----------+
| Upper Columbia     | *Oncorhynchus        | Endangered  | NE        |
| River Spring       | tshawytscha*         |             |           |
| Chinook Salmon     |                      |             |           |
+--------------------+----------------------+-------------+-----------+
| Essential Fish     | *N/A*                | N/A         | NAE       |
| Habitat            |                      |             |           |
+--------------------+----------------------+-------------+-----------+

**NE= No Effect NAE= No Adverse Effect**

### Table 2. Effect Determination Table 

**[Cultural Resources (Historical / Archeological)]{.underline}**

*Affected Environment:*

##### 

Western Shore Heritage Services, Inc. prepared a "Cultural Resources
Survey -- August 6, 2003" for Alternative 1 in compliance with Section
106, National Historic Preservation Act, as amended. The Area of
Potential Effect (APE) includes the footprint of: the proposed detention
ponds; the channel between ponds 1 and 3; the channel between ponds 2
and 7; and the Badger Mountain Road Landslide -- Head Removal Area.

*Environment Consequences:*

Based upon the survey, FEMA determined that no historic structures were
identified within the APE and that no cultural or archeological
resources were identified within the areas of ground disturbance. This
determination is applicable to all three alternatives. A copy of the
survey was sent to the Washington State Historic Preservation Officer
and to the Tribal Historic Preservation Officer for the Confederated
Tribes of the Colville Reservation with a request for their concurrence
that no historic properties are affected.

**[Socio-Economic Conditions (Including Environmental Justice -- EO
12898):]{.underline}**

*Affected Environment:*

According to the 2000 census the population of Douglas County is 32,603.
About 62% of the population lives in the unincorporated portion of the
county and about 25% live in East Wenatchee. Of the total population
77.2% are white; 19.7% are Hispanic or Latino, 1.1% are American Indian;
0.5% are Asian; 0.3% are Black & 1.2% are considered Other. The median
age is 35.7 years and 12.7% of the population is over 65 years old.

According to the U.S. Census (1999 estimates): the mean annual household
income is \$38,464 and \$45,776 for Douglas County and the State of
Washington, respectively and the persons (percent of population) below
the poverty level is 14.4% and 10.6% for Douglas County and the State of
Washington, respectively.

The primary industry in Douglas County is agriculture, including
farming/raising, warehousing, processing, packaging, and shipping. The
primary crops are apples, wheat, and cattle (there are other crop
varieties). About one third of the workforce is employed in agriculture
related activities. Other sources of employment include: education,
local government/utilities, retail trade, financial services, and
construction.

The City of East Wenatchee and Douglas County have created a combined
Storm Water Utility. The Utility boundaries include all of East
Wenatchee and the urban (developed) portion of Douglas County near East
Wenatchee. All of the property within the Utility boundary pays an
annual fee based on impervious surface (farmland and open area are not
charged). The Utility will fund the "Applicant" share of the Project and
be responsible for funding the monitoring, operation and maintenance of
the Project.

*Environment Consequences:*

The impacts for Alternative I and II would be the same. The potential
short-term impacts would be similar to any moderate sized urban
construction project in a moderately sized town. These impacts include:

-   Project opportunities for local building construction contractors.

-   Job opportunities for the construction trades.

-   Material sales for suppliers.

-   Tool and equipment purchase and rental.

-   Additional purchases of basic living necessities such as food,
    lodging, gas, and clothes (if an outside contractor and related
    crews are selected to do the project).

-   Additional truck traffic (about 4600 trips) between the excavation
    at the head of the Badger Mountain Road and the disposal site
    (location to be determined by the applicant).

-   Construction equipment activity in the project areas will create
    noise.

The potential long-term impacts include:

-   East Wenatchee, Douglas County and the property owners near Sand
    Canyon Creek will have lower emergency response costs (slide
    repairs, flood debris removal & clean-up, road/culvert repairs).

-   Douglas County will develop and implement an annual monitoring,
    operating, & maintenance program. This program may encourage
    property owners in the vicinity of project to observe, record, and
    report the effectiveness of the project and the need for
    maintenance.

-   The Utility will have increased annual monitoring, operating, &
    maintenance costs, which potentially will be passed to the
    customers.

Neither will disproportionately impact any low income or minority
populations.

[Alternative III:]{.underline}

There would be no short-term impacts. The potential long-term impacts
would be the necessity of continued repairs to the surface of the Badger
Mountain Road as the landslide continues to move. East Wenatchee,
Douglas County and the property owners near Sand Canyon Creek will
continue to have emergency response costs and inconveniences (slide
repairs, flood debris removal & clean-up, road/culvert repairs).

This alternative would not disproportionately impact any low income or
minority populations either.

##### [Land Use]{.underline}

*Affected Environment:*

Nearly all of the project area is in unincorporated Douglas County (a
portion of Pond 1 and a portion of the buttress wall are in East
Wenatchee). The Badger Mountain Landslide is in unincorporated Douglas
County. Eastmont Avenue and the majority of the mapped floodplain are in
East Wenatchee.

There are 6 distinct land uses in the vicinity of the project:

-   Dryland Agriculture and Native Open Space - the upper incised
    channel with steep side slopes (native open space) and dry land
    farming on the benches above the incised channels in the vicinity of
    ponds 3, 4, 5, & 6. Much of the farmland is in the County's
    Conservation Reserve Program;

-   Geologically Hazardous Area and Native Open Space - Sand Canyon with
    steep gradient and steep side slopes;

-   Rural Residential --the upper flat area near Badger Mountain Road
    containing Fancher Heights;

-   Agriculture - irrigated orchards from the mouth of Sand Canyon to
    Eastmont Avenue;

-   Urban --the area from Eastmont to the Columbia River containing
    residential houses, undeveloped areas, a mobile home park,
    governmental offices, and a community park.

*Environment Consequences:*

Alternates I, & II: There will be no change in land use to the Dryland
Agriculture, Native Open Space, and/or Geologically Hazardous Areas as a
result of these projects. The Residential area (Fancher Heights) has
been platted out and will continue to experience normal home
construction until filled. This project will have no influence on the
rate of construction currently occurring nor is it anticipated to
influence a change to East Wenatchee's Urban Growth Boundary. Because of
the reduced threat of flooding and sediment accumulations, the orchards
at the mouth of Sand Canyon and the undeveloped areas in the urban area
may experience conversion to a more intense use for several years. The
community park near the mouth of Sand Canyon Creek at the Columbia River
would not experience changes as a result of this project.

Alternative III: There would be no changes to current land use in the
vicinity as a result of this alternative.

##### [Safety]{.underline}

*Affected Environment:*

The proposed stormwater detention ponds, landslide buttress wall, and
material removal area are all on undeveloped, rather remote, private
property. The potential impact area for safety concerns would be the
landslide and floodplain area, which includes public roads and
infrastructure, a public park, developed private property, people and
domestic animals. The County and its contractors are required to follow
safety standards for workers, motorists, and pedestrians when working in
hazardous areas and along public roads and right-of-ways.

*Environment Consequences:*

Alternate I:

The potential short-term impacts for the pond areas include: toxic
spills (fuel, hydraulic fluids), and accidents involving construction
workers. The impacts for the buttress area and material removal area
include: toxic spills (fuel, hydraulic fluids); accidents involving
construction workers, and a catastrophic slide while the construction
activity is in progress.

The potential long-term impacts include: a reduction in the frequency
and magnitude of flood events and reduced probability of a catastrophic
landslide; the introduction of impounded water in an urban environment;
and dam breaching or failure during high flood or flash flood events.
However, according to Shannon and Wilson, Inc., the detention pond dams
would not be subject to review by the Washington State Department of
Ecology Dam Safety Section due to their small normal operating capacity.

##### 

Alternative II:

The potential short-term impacts include: toxic spills (fuel, hydraulic
fluids), and accidents involving construction workers.

The potential long-term impacts include: a reduction in the frequency
and magnitude of flood events and dam breaching or failure. However, due
to the size of the detention ponds, a permit would be required by the
Washington State Department of Ecology Dam Safety Section for
construction of the dams. The slide areas will continue to move, albeit
at a reduced rate, resulting in cracks and bumps in Badger Mountain
Road. The potential for a catastrophic landslide will continue.

Alternative III:

There would be no changes to the current short or long-term impacts.
There is still the risk of catastrophic landslide. The slide areas will
continue to move resulting in cracks and bumps in Badger Mountain Road.
And high flows during high rainfall and/or snowmelt events will still be
experienced. The current risk to loss of life and property will continue
based upon the nature of a flash flood.

##### [Cumulative Impacts]{.underline}

Cumulative impacts are those effects on the environment that result from
the incremental effect of the action when added to past, present, and
reasonably foreseeable future actions, regardless of what agency
(Federal or non-Federal) or person undertakes such actions. Cumulative
effects can result from individually minor, but collectively
significant, actions taking place over a period of time.

For this discussion "Past" is considered the time before development
(roads, buildings, and farms) along the Columbia River and benches to
the east; "Present" is considered the development time frame; and the
"Future" is considered the reasonable foreseeable future.

In the "Past" there were flash floods, erosion, landslides, and
sedimentation (creation of alluvial fan) associated with the sand canyon
drainage basin. Because there were no significant damages associated
with these events there was no concern. According to the Cultural
Resources Survey by Western Shore Heritage Services, Inc the Columbia
Salish tribe occupied the east side of the Columbia River. The tribes
fished in the river and hunted and gathered in the upland areas.

In the "Present" the flash floods, erosion, landslides, and
sedimentation (creation of alluvial fan) associated with the sand canyon
drainage basin continued. Development occurred on the alluvial fan, in
the flood plain and across the landslide area without acknowledging or
making provisions for protecting against these hazards. Because of this
development there were damages (undersized culverts, breached and eroded
roads, flooded homes, undesirable sediment accumulations, and
differential settlement on the Badger Mountain Road crossing a large
landslide area). As a consequence Douglas County, East Wenatchee, and
property owners have responded during the emergencies and made post
event clean up and repairs.

The "Future" cumulative impacts as a result of Alternative I are
expected to include: increased development, construction of the CIP
upgrade of the Badger Mountain Road, decreased costs associated with
emergency response, clean up, and repairs, and increased monitoring and
maintenance of ponds and buttress wall.

> Increased Development: The orchard area at the mouth of Sand Canyon
> east of Eastmont Avenue and the occasional vacant lot in the flood
> plain between Eastmont Avenue and the Columbia River can be expected
> to be developed. This development would most likely be consistent with
> the existing development in the surrounding area and current zoning
> and codes. The flooding risk to these new developments will be minimal
> because the post project 100-year flood will be contained in channel
> and the existing culverts have the capacity to pass the peak design
> flow.
>
> Construction of the Badger Mountain Road Upgrade: Douglas County has
> plans to continue with the design and construction of this project.
> The stabilization of the Badger Mountain Road Slide will reduce
> construction and long-term repair costs.
>
> Decreased costs associated with emergency response, clean up, and
> repairs: Douglas County, East Wenatchee and the property owners can
> reduce their emergency response, clean up, and repair efforts because
> the 100 year flood will be controlled, sediment collected in ponds,
> and the Badger Mountain Road Slide will be more stable. The resources
> used for these activities can be directed elsewhere.
>
> Increased monitoring and maintenance of ponds and buttress wall:
> Douglas County and East Wenatchee will develop and implement a
> long-term monitoring and maintenance program for the ponds and
> buttress wall. The Storm Water Utility will finance this program.
> Staff will be selected, equipped, and trained to implement the
> program.

**[Factors Considered, Not Discussed:]{.underline}**

The following "other" factors were considered and it was determined
there were no (or minimal) potential effects: Prime Farmlands,
Vegetation, Wildlife, Climate & Air, Mineral Resources, Utilities, and
Noise. There is no further discussion of these "other" factors in this
document.

> **MITIGATION OF UNAVOIDABLE ADVERSE IMPACTS ASSOCIATED WITH THE
> ALTERNATIVES**

Mitigation refers to actions that would reduce or eliminate potential
adverse environmental impacts that could result from the proposed
action. The potentially adverse impacts described in the previous
section are minor and do not require any formal mitigation.

Mitigation measures for Alternates 1, & 2 are similar and include:

1.  Douglas County will be responsible for obtaining and complying with
    all required local, state, and Federal
    permits/regulations/codes/standards (including but not limited to:
    Shoreline Conditional Use, Floodplain Management, Critical Areas
    Ordinance, WSDFW-HPA, WSDoE-401, US Army Corps of Engineers Section
    404, WSDoT, and APWA) prior to and during project implementation.

2.  The construction will comply with local, state, and federal
    requirements related to preparation and implementation of erosion
    control plans, allowable turbidity, discharge of storm water from
    construction sites, periodic inspections, and use of clean and
    well-maintained equipment.

3.  Should historically or archeologically significant materials (or
    evidence thereof) be discovered during the implementation of the
    project, the project shall be halted until FEMA (in consultation
    with SHPO, the Applicant and other concerned parties) develops and
    implements appropriate measures to ensure the project is in
    compliance with the National Historic Preservation Act.

4.  Douglas County will be responsible for the continued monitoring,
    operation, and maintenance of all facilities associated with the
    project. The monitoring will include checking for maintenance needs,
    emergency response activities, and project effectiveness. Operating
    and maintaining will include cleaning, repairing, and adjusting the
    projects. The surface water management unit will be responsible for
    evaluating rainfall, snowmelt, inflow, outflow, pond depth, and
    maintenance reports and developing and implementing plans to adjust
    pond outlet configurations.

5.  If deviations from the proposed scope of work result in substantial
    design changes, the need for additional ground disturbance,
    additional removal of vegetation, or result in any other
    unanticipated changes to the physical environment, the Grantee must
    contact FEMA, and a re-evaluation under NEPA and other applicable
    environmental laws will be conducted by FEMA.

**AGENCIES CONSULTED**

The Washington State Historic Preservation Officer (SHPO), Dr. Allyson
Brooks, was consulted for Historical and Archeological effects by letter
dated August 28, 2003.

The Tribal Historic Preservation Officer (THPO) for the Confederated
Tribes of the Colville Reservation, Dr. Shawn Hess, was consulted for
Historical and Archeological effects by letter dated August 28, 2003.

Douglas County consulted with the following agencies regarding this
proposed project: US Army Corps of Engineers, Debbie Knaub, (at Project
Scoping Meeting - March 11, 2003).

NOAA Fisheries, Dianne Driscoll US Fish and Wildlife Service, (at
Project Scoping Meeting - March 11, 2003).

Washington State Department of Fish and Wildlife, Bob Newman, (at
Project Scoping Meeting -- March 11, 2003)

V.  **REFERENCES:**

Anderson, Kim; Baker, Mark; Fisher, Cameron; Long, Alissa; Paulus,
Stuart. *ENSR International Sand Canyon Hazard Mitigation Site Wetland
Delineation*. East Wenatchee, Washington, Aug. 2003.

Burrie, Dee. J., P.E. *Draft Engineering Study; Sand Canyon Flood
Mitigation Project*. Douglas County. Washington Shannon & Wilson, Inc.,
2003.

Burrie, Dee. J., P.E. *Supplemental Pond Storage and Flow*. Shannon &
Wilson, Inc., 2003.

[Douglascountywa.net]{.underline}. *Storm Water Utility.* 8 Aug. 2003.
<http://www.douglascountywa.net/departments/swu/>.

[Factfinder.census.gov]{.underline}*.* 12 Aug. 2003. *U.S. Census
Bureau, DP-1 Profile of General Demographic Characteristics.* Data Set:
Census 2000 Summary File (SF 1) 100-Percent Data.
<http://factfinder.census.gov/bf/>.

Gosselin, Jolene. *Hazard Mitigation Grant Application.* Douglas County,
2001.

Gosselin, Jolene, P.E. *Personal Communications.* County Engineer.
Douglas County, 2003.

Hancock, LeeAnn. *Sand Canyon Flood Hazard Mitigation FEMA Biological
Assessment*. Washington State Department of Transportation. Douglas
County, July 2003.

*[Idahogeology.org]{.underline}.* 11 April 2002. Uniform Building Code
Seismic Zone Map of the Contiguous United States.
*<http://idahogeology.org/Services/GeologicHazards/Earthquakes/images/ubc.gif>.*

Lange, Jennifer, P.E. *Personal Communications.* Design Engineer.
Douglas County, 2003.

Rooke, Lara C. *Sand Canyon Flood Hazard Mitigation Project.* Washington
State Office of Financial. Cultural Resources Survey for the Management.
2003 Population Estimates Western Shore Heritage Services, Inc., 6 Aug.
2003.

Roozen, Justin, Road Data/Environmental Coordinator. *Personal
Communications.*

Douglas County, 2003.

Roozen, Justin. *State Environmental Policy Act Checklist.* Douglas
County, 2003.

*Task Force on the Natural and Beneficial Function of the Floodplain*.
The Natural and Beneficial Function of the Floodplain. Reducing Flood
Losses by Protecting and Restoring the Floodplain Environment. June
2002.

*Top 10 Employers in Douglas County.* Port of Douglas County, October
2002.

> *U.S. Department of Housing & Urban Development.* Federal Insurance
> AdministrationFlood Insurance Rate Map. Douglas County, Washington.

*Washington State Department of Ecology*. Facility/Site Identification
System, 2003.

**IX. APPENDICES:**

#1 - Maps:

> Map #1 -- Location & Drainage Map
>
> Map #2 - Alternative #I
>
> Map #3 - Alternative #II

#2 - Photos:

Photo #1 -- Cover and Overview

Photo #2 - Pond 1 Proposed Location

Photo #3 - Pond 2 Proposed Location

Photo #4 -- Ponds 3, 4, 5, & 6 Typical Conditions

> Photo #5 - Buttress Wall Proposed Location

#3 -- Executive Orders Checklists:

Executive Order 11988 (Floodplain Management)

Executive Order 11989 (Wetlands)

#4 -- Public Involvement

Public Notice for FEMA Draft Environmental Assessment

> Summary -- Douglas County (Sand Canyon) HMGP Public Notices & Hearings
>
> #5 -- Comments from Agencies
>
> #6 -- Comments from Public

#7 -- Draft Engineering Study;

#8 -- Cultural Resources Survey

#9 -- Biological Assessment

#10 -- Wetland Delineation