NFBR Mining Supplemental EIS Appendix 1C

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APPENDIX 1 C

Site Characteristics Used to Develop Forest Service 

Water Quality Protection Measures

All proposed mining sites were visited by the Forest hydrologist in 2006, 2007, and 2008. The 

proposed mining sites varied by topography, ground cover, presence of stream tailings, microtopography, presence of beavers, and presence of adits. Based on the site characteristics, Water 

Quality Protection Measures (WQPMs) were developed (Appendix 1A) to eliminate the potential 

for a discharge of pollutant in to any channel and ensure compliance with INFISH MM-1 and 

MM-2. While variability existed between sites, they fell into the general categories listed 

below. 

1. Operations on valley floor

a. No placer tailings line the channel bank

b. Placer tailings line the channel bank

2. Operation on a hillslope

a. No placer tailings line the channel bank

b. Placer tailings line the channel bank

3. Beaver dams

a. Currently present 

b. Likely to be present at sometime in the near future

4. Adit present

a. Not discharging water

b. Discharging water and within 300 feet of perennial stream or natural wetland 

BUT not discharging directly into either 

i. Operation plans to use adit water BUT not work the lode.

ii. Operation plans to use the adit water AND work the lode.

iii. Operation will not use the adit water OR work the lode.

c. Discharging water and within 300 feet of perennial stream or natural wetland 

AND discharging directly into one or the other 

i. Operation plans to use adit water BUT not work the lode.

ii. Operation plans to use the adit water AND work the lode.

iii. Operation will not use the adit water OR work the lode.
Appendix 1C NFBR Mining Supplemental EIS

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d. Discharging water and greater than 300 feet from perennial stream or natural 

wetland

i. Operation plans to use adit water BUT not work the lode.

ii. Operation plans to use the adit water AND work the lode.

iii. Operation will not use the adit water OR work the lode.

5. Miscellaneous Site Characteristics

Discussion of Site Characteristics for each Category

1. Operation on valley floor: Starting point of buffer measurement clarified and buffer 

widths adjustments made from Alternative 2

a. No placer tailings line the channel bank

Most proposed Plans of Operation identified buffers around streams, wetlands, and springs. 

However, the location of where the buffer measurement started was often ambiguous because it 

was tied the stream. The low-flow stream varies in width from year to year and within a given 

season, and the wetted edge is therefore not a fixed location. Identifying the high spring flow 

edge requires evaluating a number of field elements (i.e. vegetation type, erosion lines, bar 

morphology) to determine the hydrologic bankfull or yearly high flow edge to a stream 

(Harrelson et al. 1994). Because many of these channels have widened and incised, there are 

often multiple points that one could chose from when measuring a distance “from the creek”. 

For example, in Figures 1 and 2, Points A, B, and C all meet that definition but at progressively 

higher stream flows (Point A being the low flow or summer flow edge and Point C being the 

very high flood event edge).

The ambiguity raised questions about where the miner planned to start their buffer measurement: 

Was the plan referring to the 1) the low-flow stream edge during operation which would vary 

from year to year, 2) from the stream edge as defined by the high spring runoff flow and if so 

what where the indicators used to determine that location or 3) from the top of the stream bank or 

edge of terrace? Was the intention of the miners to stay out of the active floodplain or off 

unstable banks? This ambiguity is a problem because the starting location of the buffer 

measurement determines the degree to which a buffer eliminates the potential for a discharge of 

sediment into navigable waters as defined by the CWA. 
NFBR Mining Supplemental EIS Appendix 1C

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Figure 1. Shows the location of the Valley floor terrace (historic floodplain) –Channel break-inslope geomorphic feature. Note that this edge is NOT the streambank of the active channel but 

the streambank of the larger geomorphic channel. The active channel is inset into the 

geomorphic channel. Elevation (ft)

Distance (ft)

Active Channel

Active Floodplain 

(point bar)

Geomorphic bankfull channel

Valley floor terraceChannel bank break in 

slope (Point C)

Valley floor terrace -

Channel bank break in slope

Back edge of active 

Floodplain (Point B)

Edge of low-flow stream 

channel (Point A)

Valley Floor/Historic 

floodplain
Appendix 1C NFBR Mining Supplemental EIS

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Figure 2. North Fork of the Burnt River. Solid yellow arrow at the location of the valley floorchannel bank (VFT-CB) break-in-slope feature (Point C). Dashed yellow arrow is at the point 

bar which is part of the active floodplain. 

In order to eliminate the ambiguity and ensure no potential for a discharge of a pollutant, 

regardless of stream flow, a geomorphic rather than hydrologic feature was selected as the 

starting point for the buffer measurement. The geomorphic feature chosen as the starting point 

was the valley floor terrace-channel bank (VFT-CB) break-in-slope when present (Figures 1 and 

2). This geomorphic feature is clearly visible in the field and does not vary from year to year or 

within a season, unless an erosional event has occurred. The valley floor is the historic 

floodplain which has been isolated from the stream as a result of channel widening and incision 

due to historic land use. The selection of this geomorphic feature as the starting point puts 

proposed mining activities on the valley floor and outside the active floodplain, stream banks, 

and valley floor terrace banks. Current vegetation on the valley floor is drought tolerant, 

indicating that this geomorphic surface is rarely flooded. 

Point C: Valley floor 

terrace-Channel breakin-slope (historic 

floodplain)

Point A: Edge of low 

flow/summer flow channel 

Point B: Edge 

of active 

floodplain 
NFBR Mining Supplemental EIS Appendix 1C

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Figure 3 shows how the buffer zone location, and its ability to prevent a discharge of pollutant, 

varies depending on how the “creek edge” is defined and the topography. In Scenario 1, the 

operation would be in the stream bank that borders the active floodplain. In Scenario 2, the 

operation would be on the valley floor terrace, but close to the stream cut bank that borders the 

active floodplain. Disturbance of the cut bank in Scenarios 1 and 2 would result in sediment 

moving into the active floodplain which would then be delivered to the stream the following 

spring. In Scenario 3, the operation would be clearly on the valley floor terrace with 25 feet of a 

no-activity zone separating the activity from the stream cut bank. In Scenario 4, the operation 

ends up on a steep hillslope. 

Figure 3. Example of how the selection of a different starting point results in a different location 

for the operation. Any of these buffer starting points would meet the “from a creek” reference. 

In this example, buffer distances are 25 feet in all scenarios.

-20

-15

-10

-5

0

5

10

15

20

0 25 50 75 100 125

Elevation (ft)

Distance from Left Pin (ft)

Annual Floodplain 

(point bar)

Scenario 3

Scenario 2

Scenario 1

Scenario 4

Low flow

channel

Point C

Point A

Point B
Appendix 1C NFBR Mining Supplemental EIS

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Buffer widths in the plans submitted by the operators varied from 10 to 25 feet from the stream. 

The Forest Service hydrologist examined those plans and after clarifying the buffer starting point 

and evaluating the topography, and in the absence of any other circumstances (i.e. presence of 

placer tailings lining the edge of the valley floor, buffer distances were started at 25 feet and 

increased as slope increased and/or ground cover decreased. The literature review by Belt et al. 

(1992) discussed the effectiveness of buffer strips on sediment movement. Their review 

identified slope and density of obstructions as the key factors controlling sediment movement 

through a buffer strip. Valley floors tend to be flat, or may have considerable micro topography

due to historic mining. Ground cover percentages were found to vary from 50 to 100 percent 

depending on the amount of grazing that is occurring in an area. The flat topography and ground 

cover results in sediment generated by mining activity moving as sheet, rather than channelized, 

flow which limits the distance sediment can travel. Given the limited ground disturbance at any 

one time in a given operation, and the other general requirements that address stockpiled top soil 

and reclamation, the 25-foot buffer was determined to be sufficient to prevent sediment from 

entering the stream channel. 

b. Placer tailings line the channel bank

Many operations state that they will have a 25-foot buffer in place to protect water quality. The 

starting point of measurement is, however, not clearly stated (See Figure 3) and the effectiveness 

of the proposed buffer varies as a function of that starting point. For example, many proposed 

mining sites have old placer tailings lining the stream banks. In these cases, a 25-foot buffer 

may put the mining operation behind the tailings, in other places within the same operation it 

would but the mining operation in front of the tailings or on top of the tailings (Figure 4). In the 

two latter cases, the 25-foot buffer would not be sufficient and there would be a potential for a 

discharge of sediment into the creek. Therefore, the following modification was made. 

The buffer location was tied to the location of the placer tailings lining the streambank and 

operations placed behind the tailings instead of being assigned a fixed distance (i.e. 25 feet).

Because the location of the tailings with respect to the valley floor terrace-channel break-in-slope 

(VFT-CB) feature varied along the stream, the distance between the operation and the stream 

varied (Figure 4), in some cases being within 10 feet of the break-in-slope feature. However, 

the tailings effectively trap sediment and, where present, completely prevent delivery of any 

sediment generated by the mining activity. Where there are breaks in the tailings piles and the 

potential for sediment reaching the creek, the 25-foot buffer distance from the VFT-CB break-inslope feature was invoked along with additional protection measures such as installing straw 

bales or silt fences.
NFBR Mining Supplemental EIS Appendix 1C

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Figure 4. Schematic showing how using the placer tailings piles results in a variable distance 

from the VFT-CB break-in-slope and the stream. BROWN line represents the VFT-CB breakin-slope location.

2. Operations on hillslopes: Starting point of buffer measurement clarified and buffer 

widths adjustments made from Alternative 2 (reference Figure above)

Operations that occurred on hillslopes fell into three general categories: 1) hillslope feeds into a 

valley floor terrace where the bench is between 15 and 25 feet wide, 2) hillslope feeds into a 

valley floor terrace where the valley width (bench) is more than 25-feet wide, or 3) hillslope 

feeds directly into the stream or where the valley floor terrace is less than 15-feet wide. Where 

activity was occurring, buffer widths were adjusted as needed to create enough of a buffer strip 

to capture any sediment generated by activity on the hillslope. The concern with activity on 

hillslopes is the potential to have channelized flow which is capable of carrying sediment much 

further than overland flow (Belt et al. 1992). In some cases, where ground cover was limited, the 

hillslopes steep, and/or the valley floor was either absent or narrow, additional requirements 

were included, such as silt fences or straw bales to prevent sediment delivery to a stream 

channel. 

3. Beaver dams 

Beaver dams would not be breached or otherwise disturbed. Instead, operators would evaluate 

under what conditions a beaver dam could pose a problem to their operation ahead of time and 

would work with the district hydrologist to design and build pond-elevation control features. 

25 feet

XXXX

XXXX

XXXX

XXXX

Placer Tailings 25 feet

XXXX

XXXX

XXXX

XXXX XXXX

XXXX

XXXX

XXXX

Placer Tailings 25 feet

XXXX

XXXX

XXXX

XXXX

Placer Tailings 25 feet

XXXX

XXXX

XXXX

XXXX XXXX

XXXX

XXXX

XXXX

Placer Tailings

Proposed mining activity

Stream

VFT-CB break 

in slope

Valley floor
Appendix 1C NFBR Mining Supplemental EIS

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These methods allow for beavers and beaver dams to remain and continue to provide water 

quality and habitat benefits, while preventing the ponds from flooding the mining operations. 

4. Adit waters

Several plans, located in the headwaters of various streams, proposed using water from adits for 

their processing. This water would be piped into processing and settling ponds and allowed to 

evaporate or seep into the ground and therefore would not directly discharge into surface water 

or channels that would transfer the water to a perennial stream or wetland. 

5. Miscellaneous Site Characteristics

The August Placer pond, located on the top an old mining dump, would be moved to prevent the 

pond water infiltrating into the dump tailings and mobilizing heavy metals. 

Upper Geiser Placer processing site would not be moved because its current location has no 

potential for sediment delivery to a stream.