Coquille Indian Tribe
Tribal Non-Point Source Assessment Model
Summary and Methods
Prepared By: Bryan Duggan
Water and Environmental Specialist
Coquille Indian Tribe
Land Resources and Environmental Services Department
September 30, 2010
Coquille Indian Tribe
CIT NPS Assessment Model
INTRODUCTION
The Coquille Indian Tribe (Tribe), with 861 enrolled tribal members, is located in
Coos Bay/North Bend, Oregon, on the southwestern Oregon coast. The Tribe was
displaced by the federal government and dispossessed of their lands under adverse
assimilation and termination policies in the 1950s. A dedicated effort by the Tribe
resulted in the restoration of their Federal tribal status under the Coquille Restoration Act
(Act), which was passed by the United States Congress in 1989.
Since 1993, the Tribe has acquired approximately 6,482 acres of trust lands in 21
separate parcels located throughout Coos County. These properties include the Empire
Reservation (Reservation), Tribal Administration Building, The Mill Casino, Heritage
Place, Metcalf Tract and Charleston Industrial Park Tract all in the Coos Watershed, and
5,400 acres of the Coquille Forest in the Coquille Watershed transferred from the Bureau
of Land Management in September 1998 to the BIA to be held in trust for the Tribe.
TRIBAL LANDS DESCRIPTION
The Tribe’s 1,100-acre Reservation is located in Coos County, Oregon, east of Cape
Arago Highway and immediately southwest of the City of Coos Bay on the southwestern
Oregon coast. It includes two separate parcels referred to as the South Parcel and the
North Parcel. The South Parcel is the largest with approximately 754 acres, and contains
Fourth and Tarheel Creek watersheds; including their two respective reservoirs, and all of
the Tribe’s current residential and infrastructure development to date. The North Parcel
which includes First and Second Creek watersheds is approximately 291 acres, and
remains largely undeveloped and yet receives heavy stormwater discharge impacts from
adjacent urban development.
There are four streams and two reservoirs associated with the Reservation; these
small second order streams all flow into lower Coos Bay and have the potential for
significant fisheries restoration improvements. All four streams have been impacted by
various historical activities during the past 150 years, including coal mining, logging,
road construction, utility corridors, and residential neighborhood development. The Tribe
utilizes multiple forestry and wildlife management plans to manage the resources of the
Reservation.
The Coquille Forest comprises approximately 14 separate parcels of land totaling the
5,400 acres of Coquille Indian Tribe trust land in the Coquille Watershed. There are no
rivers flowing through the Coquille Forest, but rather a series of approximately 60 miles
of smaller headwater streams and their associated riparian systems which flow into the
East Fork, Middle Fork, and South Fork Coquille River watersheds.
The Coquille Forest was transferred from the Bureau of Land Management to the
BIA to be held in trust for the Tribe under the terms of the 1996 Coquille Forest Act.
Public Law 104-208 creating the Coquille Forest requires that management of these
Tribal forest lands will be subject to the standards and guidelines of Federal forest plans
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CIT NPS Assessment Model
on adjacent Federal lands, now and in the future. The Federal lands adjacent to the
Coquille Forest are Bureau of Land Management (BLM) lands under jurisdiction of the
Coos Bay District. The BLM Coos Bay District manages Federal lands under the
Proposed Resource Management Plan [PRMP]/Environmental Impact Statement [EIS]
dated September 1994 which complies with the management standards and guidelines of
the Northwest Forest Plan. Consequently, the Coquille Forest is managed under separate
guidelines as the Reservation and so requires a different set of strategies to mitigate
management activity impacts. Other lands adjacent to the Coquille Forest include private
timber companies who in of themselves manage their lands under differing management
strategies, and can often be challenging in reconciling impacts from adjacent
management plans.
Water quality and aquatic habitat in streams of the Tribe’s Reservation and Coquille
Forests have been and continue to be impacted by Non-Point Source (NPS) pollution.
Most of the Reservation has been severely affected by previous timber harvests and other
activities that occurred prior to 1997. Sources on the Reservation include sedimentation
due to runoff from roads and past and current silvicultural activities, pollutant loading
from urban development on and adjacent to the Reservation, forest road erosion impacts,
and specialty crop agricultural nutrient pollutants. The previous activities removed
vegetation, disturbed soils and altered drainages, thereby causing heavy erosion and
impacts to water quality. The Coquille Forest lands have seen similar, but less severe
NPS impacts from forest road construction, forest product hauling and other public uses.
The challenge for the Coquille Forest is to manage for optimal water quality within small
watersheds that either originate or flow outside the Tribe’s control and through adjacent
lands where there are differing management objectives and policies.
Since 2006 the Tribe has received USEPA Clean Water Act Section 319 funding to
implement NPS control projects on the Empire Reservation. Beginning in 2010 the Tribe
has drafted an amendment to its Treatment-As-A State agreement with the EPA to
include the 5,400 acres of trust lands (Coquille Forest) within the East and Middle Forks
of the Coquille River for inclusion within the Tribe’s § 319 NPS Program. In order to
begin utilizing EPA § 319 funds on the Coquille Forest, a non-point source assessment
and a non-point source management plan are necessary to guide effective NPS mitigation
actions.
According to the EPA, road construction and road use are the primary sources of NPS
pollution on forested lands, often contributing up to 90 percent of the total sediment from
forestry operations. To adequately assess tribal forest management activities as it relates
to NPS pollution, it becomes important to analyze all points of hydrological connectivity
between forest roads, project action areas, and the surface waters that connect them.
This document summarizes the efforts of the Tribe’s Biological and Environmental
Services (BES) Program and the Tribe’s Geographic Information Systems (GIS) program
to develop and assess an NPS Prioritization Model. This will be used to provide a NPS
risk index on tribal lands and adjacent access routes which may be impacted by Tribal
Forest Management Activities. This document was written to meet the objectives for the
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CIT NPS Assessment Model
Tribe’s Clean Water Act § 319, NPS base work plan; to revise the Tribe’s NPS
Assessment Report; and, to include the inventory and assessment of all current and
proposed sivilcultural activities on the Coquille Forest that have the potential to affect
water quality within tribal waters.
METHODS AND PROCEDURES
The Tribe developed an analytical framework to asses the numerous soil, hydrology,
and road variable properties into a Tribal Non-Point Source Assessment Model that will
be able to map and identify roads or project areas that are at risk to high levels of NPS
pollutant loading. From this model, the Tribe will be able to develop a prioritization list
of roads and projects that are in need of Best Management Practices (BMPs) or additional
water quality monitoring.
To begin the process, tribal staff mapped and verified road and stream crossings on
the Tribe’s Empire Reservation and Coquille Forest lands utilizing Geographic
Positioning System devices and ArcGIS 9.3 software. The Tribe developed a new Culvert
and NPS Threat Datasheet (CNPS) to assist in monitoring the road and stream interface
on tribal lands (Appendix A). The Tribe’s CNPS Datasheet tracts culvert metrics such as:
type, material, diameter, height, width, length, gradient, culvert condition, fish passage
status, and culvert restoration priority. NPS pollution metrics include: natural barrier
type, road surface type, ditchline condition, bank conditions, BMP needs, turbidity
measurements, and a NPS index priority of low, moderate and high.
The objective of the Tribe’s CNPS Datasheet is to determine the condition and
connectivity of the culvert with emphasis on rating the sites potential to contribute
sediment pollution into the connected water body. Culverts and associated road beds
within perennial stream channels are rated as having a high connectivity to the watershed
while culverts within intermittent stream channels were rated as having a low
connectivity to the watershed. Culverts with a high connectivity and unstable bank
conditions rated as having a higher NPS threat priority than did culverts that had no
connectivity to the perennial stream channel. Culverts with a high connectivity index, but
stable bank conditions were rated as having a moderate NPS threat priority; and those
culverts with stable banks and little to no connectivity were rated as having a low NPS
threat priority.
Figure 1. illustrates the combined programmatic steps needed to build the NPS
Assessment Model for Coquille Tribal lands.
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CIT NPS Assessment Model
Figure 1: Steps taken to build the CIT NPS Assessment Model.
Mapped culvert and
road stream crossings
on Reservation and
Coquille Forest
Field verified
culvert sites
Compiled soil
survey information
Generated a physical soils report for
Empire Reservation and Coquille
Forest from Coos County soils
database
Ran a RUSLE2 related attributes
report for Empire Reservation and
each Coquille Forest Parcel
Generated 18 maps of Empire Reservation and Coquille Forest Parcels that identify active
operations, roads and their associated Soil Hydrological Groups and Runoff Potential
The GIS Coordinator (GISC) compiled a physical soils report for each tribal parcel
from the Coos County, U.S. Department of Agriculture and the Natural Resources
Conservation Services’ soils database. These soils reports listed the depths and
characteristics of soil types found on the parcels, along with erosion factors, moisture
bulk density, saturated hydraulic conductivity, and available water capacity factors. Then
a RUSLE2 related attribute report was generated for each of the Coquille Forest parcels
and the Empire Reservation to characterize the soils into a low, moderately low,
moderately high, and high hydrological soil groups. An attribute table allows for a
selective caching of data upon which a model can generate maps and information
pertinent to the subject. The RUSLE2 attribute report summarizes the larger and more
detailed soils reports into an attribute table of soils ranked by their perspective
hydrological groups. These hydrological soil groups were generated based on the soils
erosion potential, permeability, and percentage of composition.
A runoff potential index letter (A, B, C, or D) was assigned to each hydrological soil
group, to correspond with a respective Low, Moderately Low, Moderately High, and
High runoff potential. The four hydrological soil groups (and letters) are defined as
follows from the U.S. Department of Agriculture’s National Engineering Handbook: Part
630 Hydrology:
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Group A- Soils in this group have a low runoff potential when thoroughly
wet. Water is transmitted freely through the soil. Group A soils typically
have less than 10 percent clay and more than 90 percent sand or gravel and
have gravel or sand textures. The limits on the diagnostic physical
characteristics of group A are as follows. The saturated hydraulic
conductivity of all soil layers exceeds 40.0 micrometers per second.
Group B- Soils in this group have moderately low runoff potential when
thoroughly wet. Water transmission through the soil is unimpeded. Group B
soils typically have between 10 percent and 20 percent clay and 50 percent
to 90 percent sand and have loamy or sandy loam textures. The limits on the
diagnostic physical characteristics of group B are as follows. The saturated
hydraulic conductivity in the least transmissive layer between the surface
and 50 centimeters ranges from 10.0-40.0 micrometers per second.
Group C- Soils in this group have a moderately high runoff potential when
thoroughly wet. Water transmission through the soil is somewhat restricted.
Group C soils typically have between 20 percent and 40 percent clay and
less than 50 percent sand and have loam, silt loam, sandy clay loam, clay
loam, and silty clay loam textures. The limits on the diagnostic physical
characteristics of group C are as follows. The saturated hydraulic
conductivity in the least transmissive layer between the surface and 50
centimeters is between 1.0 micrometers per second and 10.0 micrometers
per second.
Group D- Soils in this group have a high runoff potential when thoroughly
wet. Water transmission through the soil is restricted or very restricted.
Group D soils typically have greater than 40 percent clay, less than 50
percent sand, and have clayey textures. In some areas, they also have high
shrink-swell potential. The limits on the diagnostic physical characteristics
of group D are as follows. For soils with a water impermeable layer at a
depth between 50 centimeters and 100 centimeters, the saturated hydraulic
conductivity in the least transmissive layer is less than or equal to 1.0
micrometers per second. For soils that are deeper than 100 centimeters to a
restriction or water table, the saturated hydraulic conductivity of all soil
layers within 100 centimeters of the surface is less than or equal to .40
micrometers per second.
From this data the GISC generated a Soil Hydrologic Groups Runoff Potential
(SHGRP) mapping layer, utilizing GArcGIS 9.3 software. The GISC then generated a
map utilizing this SHGRP layer along with a roads layer, stream layer, property boundary
layer, and an active operations layer to demonstrate the runoff potential for all activities
and road stream crossings on each tribal parcel.
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Coquille Indian Tribe
CIT NPS Assessment Model
The Tribe considers this model an evolving framework, which is subject to periodic
review and adaptation as part of the Tribe’s continuous NPS monitoring process; and will
continue to develop a sediment risk index for all current and future resource management
activities on tribal lands.
RESULTS
The model outcome generated 15 Physical Soil Properties Tables (Appendix), 15
RUSLE2 Attribute Tables (Appendix) and 15 maps (Appendix) of the Empire
Reservation and Coquille Forest lands which identified NPS priorities based on the
location of stream crossings, culvert types, road types, and soil hydrological groupings.
Empire Reservation
Soil Hydrologic Group (SHG) results indicate predominance of moderately low to
moderately high soil hydrologic runoff potential on both parcels of the Empire
Reservation. With 73% of the acres on the North Parcel falling within a Moderately High
SHG, and 18 stream crossings, the North Parcel remains high in priority for continued
NPS monitoring (Table 1). With 83% of the acres on the South Parcel falling within a
Moderately Low SHG, the management priority would be low; however with almost
double the stream crossings (Table 1), the South Parcel management priority remains
moderate.
Table 1. Hydrological Soil Groups and Runoff Potential Results for the Coquille
Forest Parcels.
Parcel ID
Empire
Res. North
Parcel
Empire
Res. South
Parcel
Soil Hydrologic Group Runoff Potential
%
%
%
% Low Moderately Moderately
High
Low
High
# Active
Project
Areas
# of Stream
Crossings
0
18
27
73
0
30
83
13
Mgt
Priority
Moderate
1
Moderate
Coquille Forest Lands
Soil Hydrologic Group results indicate predominance of moderately low to
moderately high soil hydrologic runoff potential on Coquille Forest lands. At 15%,
Coquille Forest Parcel 6 was the only parcel to have a percentage of lands with a high
runoff potential. Coquille Forest Parcels 8, 9, 11, and 13 were the next lands to have
significant percentages of acreage in the moderately high runoff potential category, at
72%, 98%, 88%, and 99% respectively. Of the eleven Coquille Forest lands with
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CIT NPS Assessment Model
moderately high runoff potential, three of them had active forest management projects on
them. Most significantly, Coquille Forest Parcel 13 is a high priority area with one active
project, and has a soils with99% moderately high runoff potential. Coquille Forest
Parcels 11 and 12 are also identified as lands with ongoing activities occurring with fairly
erodible soils; and therefore; the soil runoff potential is high. Given this information the
Tribe should implement more BMPs and conduct a heavier monitoring regime. Table 2
quantifies the percentage of Soil Hydrologic Groups alongside the number of active
forest management projects and stream crossings by parcel for the Coquille Forest.
A Management Priority index was determined for each forest parcel based on the
number of active projects on a parcel compared to the SHG percentage and number of
stream crossings. Parcels 1-4 are rated a low priority because, although they have
moderate percentages of acreage in a moderately high runoff potential, no active projects
are occurring at this point. Coquille Forest Parcel 5 is rated as a moderate priority
because it has an active project on site with numerous stream crossings; even though
100% of the parcel’s acreage falls within the moderately low SHG index. Coquille Forest
Parcels 6, 11, and 12 are all rated as having a high management priority due to the high
number of active projects, coupled with a high number of stream crossings versus a high
percentage of acreage within a moderately high SHG index.
Table 2. Hydrological Soil Groups and Runoff Potential Results for the Coquille
Forest Parcels.
Parcel ID
# Active
Project
Areas
CF1
CF2
CF3
CF4
CF5
CF6
CF7
CF8
CF9
CF10
CF11
CF12
CF13
CF14
0
0
0
0
1
5
0
0
0
0
3
4
1
0
# of
Stream
Crossing
s
29
45
43
29
72
57
31
61
56
41
34
59
1
14
Soil Hydrologic Group Runoff Potential
%
%
% Low Moderately Moderately % High
Low
High
76
24
100
60
40
45
55
100
85
15
81
19
28
72
2
98
62
38
12
88
57
43
1
99
74
26
Note: CF#=Coquille Forest Parcel Number
CONCLUSION
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Mgt.
Priority
Low
Low
Low
Low
Moderate
High
Low
Low
Low
Low
High
High
Moderate
Low
Coquille Indian Tribe
CIT NPS Assessment Model
Understanding the hydrologic runoff potential of soils and the potential impacts of
land management activities on all tribal water bodies is an important step in reducing
NPS effects on tribal lands. Through the development of this Tribal NPS Assessment
Model (TNPSAM), appropriate restoration and sediment reduction strategies can be used
in addition to current BMPs, to reduce the potential for NPS impacts resulting from
Tribal Management activities.
This model easily identifies areas where the occurrence of high to moderately high
hydrologic soils runoff potential combined with a high occurrence of stream road
crossings can be problematic for water quality when planning management activities.
This model will assist the Tribe in future project planning and in implementing sediment
reduction strategies for on-going projects.
Additionally, this TNPSAM will be utilized by the Tribe to identify high risk,
adjacent land owner projects that may have the potential to impact water resources on
tribal lands. Assessment results will then assist the Tribe in providing comments to other
landowners during the consultation process for potential impacts of adjacent projects on
tribal water bodies. The TNPSAM may also be utilized to direct watershed based
restoration activities, where sensitive areas can be identified for additional monitoring or
avoidance; and where in-stream staging areas can be mapped for minimum impact.
The development of the TNPSAM marks a significant step in the Coquille Indian
Tribe’s environmental monitoring programs; an adaptable approach towards utilization of
new technologies that combined with the Tribe’s traditional commitment to resource
management, shall serve to protect aquatic resources for generations to come.
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APPENDIX
A.
Coquille Indian Tribe Culvert and NPS Threat Datasheet; 1 pg.
B.
Physical Soil Property Tables; 15 pgs.
B-1 Empire Reservation Physical Soil Properties
B-2 Coquille Forest 1 Physical Soil Properties
B-3 Coquille Forest 2 Physical Soil Properties
B-4 Coquille Forest 3 Physical Soil Properties
B-5 Coquille Forest 4 Physical Soil Properties
B-6 Coquille Forest 5 Physical Soil Properties
B-7 Coquille Forest 6 Physical Soil Properties
B-8 Coquille Forest 7 Physical Soil Properties
B-9 Coquille Forest 8 Physical Soil Properties
B-10 Coquille Forest 9 Physical Soil Properties
B-11 Coquille Forest 10 Physical Soil Properties
B-12 Coquille Forest 11 Physical Soil Properties
B-13 Coquille Forest 12 Physical Soil Properties
B-14 Coquille Forest 13 Physical Soil Properties
B-15 Coquille Forest 14 Physical Soil Properties
C.
RUSLE2 Attribute Tables; 15 pgs.
C-1 Empire Reservation Attribute Table
C-2 Coquille Forest 1 Attribute Table
C-3 Coquille Forest 2 Attribute Table
C-4 Coquille Forest 3 Attribute Table
C-5 Coquille Forest 4 Attribute Table
C-6 Coquille Forest 5 Attribute Table
C-7 Coquille Forest 6 Attribute Table
C-8 Coquille Forest 7 Attribute Table
C-9 Coquille Forest 8 Attribute Table
C-10 Coquille Forest 9 Attribute Table
C-11 Coquille Forest 10 Attribute Table
C-12 Coquille Forest 11 Attribute Table
C-13 Coquille Forest 12 Attribute Table
C-14 Coquille Forest 13 Attribute Table
C-15 Coquille Forest 14 Attribute Table
D.
Model Output Maps; 15 pgs.
D-1 Stream Crossings Map Empire Reservation
D-2 Stream Crossings Map Coquille Forest 1
D-3 Stream Crossings Map Coquille Forest 2
D-4 Stream Crossings Map Coquille Forest 3
D-5 Stream Crossings Map Coquille Forest 4
D-6 Stream Crossings Map Coquille Forest 5
D-7 Stream Crossings Map Coquille Forest 6
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D-8 Stream Crossings Map Coquille Forest 7
D-9 Stream Crossings Map Coquille Forest 8
D-10 Stream Crossings Map Coquille Forest 9
D-11 Stream Crossings Map Coquille Forest 10
D-12 Stream Crossings Map Coquille Forest 11
D-13 Stream Crossings Map Coquille Forest 12
D-14 Stream Crossings Map Coquille Forest 13
D-15 Stream Crossings Map Coquille Forest 14
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