20081317 Ver 1_Monitoring Report_20160314

HELL SWAMP 2014-2015 HEADWATER VALLEYS AND SCOTT CREEK STREAM SURVEYS
MONITORING YEAR 5/6
8 OCTOBER 2014 and 10 FEBRUARY 2015
Rainfall recorded at the Hell Swamp rain gauge in the two weeks prior to the October 2014 stream
survey was — 0.15 inch and in the two weeks prior to the February 2015 survey 1.66 inches of rain was
recorded (0.41 inch in the previous 48 hours).
Typical of many stream restoration projects, over the monitoring period the density and diversity of
herbaceous vegetation has increased steadily in most Hell Swamp headwater stream valleys and in the
single -thread portion of Scott Creek. Dense herbaceous vegetation not only obscures flow paths but also
attenuates the capacity of water that does flow to either move sediment, pick up vegetative debris, or
form other channel features. Some features noted in earlier stream surveys have become more obscure
due to denser herbaceous vegetation. Due at least in part to some shade and longer periods of standing
or flowing water, the herbaceous cover remains sparse in the lowest Scott Creek segment downstream
of the junction with UT6.
The density of herbaceous vegetation (primarilyJuncus sp., Mikania scandens, and Lespedeza sp. in
some areas) made it very difficult to confidently determine evidence of previous flow events during the
October 2014 survey. Therefore, the survey was postponed in the upper end of UT3 (the portion
upstream of constructed stream crossing along the old farm road), in upper UT6, all of UT7, and upper
Scott Creek (USC). It was decided to survey these remaining valleys/features and if time allowed to
resurvey selected sections of what was walked in October either later in 2014 or in early 2015 (post -
senescence and after wetter conditions) such that debris jams or other flow evidence may be more
visible.
The upper portions of UT3, UT6, and upper Scott Creek, and all of UT7 were surveyed in February 2015
and observations are included in separate statements in each creek or headwater valley description
below. The areas surveyed in October 2014 were not re -visited.
Lower Scott Creek (LSC):
October 2014: The most downstream section of Scott Creek was in shallow bank full condition but flow
was low to none; water depths ranged from 3 to 5 inches. View upstream from vicinity of eastern
property boundary and midstream towards junction with UT6 is shown in Photos 1 and 2. Photo 3
shows flow path just downstream of confluence with UT6.
The filled channel (old agricultural ditch dug at edge of main Scott Creek system and filled during
restoration) has increased the width of the available flow path for Scott Creek (no construction occurred
in the portion of Scott Creek south of the filled ditch channel). The old spoil piles remain as a
discontinuous berm feature along the southern edge of the filled portion of lower Scott Creek and do
not provide a continuous barrier between the main system to the south and the filled channel. In the
vicinity of gaps in this berm, water from the main stem of Scott Creek was ponded against the
downstream toe of the spoil at the edge of the filled section. The entry and exit points for likely flow
events in and out of these ponded areas were collected by GPS as well as a persistent, albeit short,
feature which appears to deliver water to the filled channel and main Scott Creek channel from the
Hell Swamp/Scott Creek Mitigation Site Appendix B-1 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

north (no flow but does show absence of vegetation) (Photo 4). In previous surveys, this short channel
lacked vegetation, but herbs have since obscured it. While no evidence of flow was visible in these
ponded areas on the day of the survey (Photos 5 and 6), it is likely that flow does occur at times along
the filled channel as long as there is an exit through another gap in the spoil at the downstream end of
the ponded water. For example, Photos 7 and 8 show a —100+ -foot long potential flowpath (Line 1)
along the filled section (note absence of vegetation compared to Photo 6 ponded area).
The constructed stream crossing along the old farm road at the upstream end of lower Scott Creek
showed no visible flow where the flow path enters the swamp; water depth was 2 to 3 inches (Photo 9).
Single -thread channel Scott Creek:
October 2014: Entire channel length choked with vegetation, water depths in channel varied from 0 to
12 inches but very low flow observed only in some locations downstream of UT1 and channel was dry at
the junction with upper Scott Creek valley. Water level in the system resulted in the runs having little to
no water while the pools had deeper water and less Bacopa sp. in the channel. Just upstream from UT1,
oriented vegetation on north side of floodplain indicated water was outside of channel at some point in
the year, as noted in earlier surveys. At flow gage 3B just downstream from UT1 low flow was noted
(Photos 10 and 11).
Upper Scott Creek (USC):
February 2015: Water depths ranged from 2.5 to 12 inches and flow was moderate to low from USC -
11B location down to the constructed stream crossing between USC -513 and -613. The short secondary
channel off the main channel was still evident and sorting and scour was observed where it joins the
main stem (Photo 12). A narrow channel feature is consistent over the uppermost part of USC valley,
with mostly moderate flow observed from USC -11B to about halfway to USC -813 location where the
slope flattened, the vegetation thickened, and flow became low. In areas of lower flow, there was
usually a clear path through the accumulated algae (Photo 13). Throughout the upper channel segment
of USC there was evidence of scour and sorting and a distinct narrow channel with almost no portions
where the channel became less evident or flow was reduced (Video 1 _1475). About 75 to 100 feet
downstream of USC -813, the narrow channel became evident again with scour, sorting, oriented algae,
and no vegetation. As noted in previous surveys, downstream from USC -713, although the valley slope
flattens and the channel becomes more distributed and less confined, low flow was evident across the
entire valley all the way to the constructed stream crossing and beyond.
UT6:
October 2014: Only the extreme lower end of this valley (where it joins the filled ditch of lower Scott
Creek) was included in the October survey due to vegetation density as described above. Video 2_1250
captures the flow and characteristics of the narrow persistent channel at the bottom of UT6 just
upstream of and at the junction with lower Scott Creek swamp and the filled farm ditch.
February 2015 survey: Low to moderate flow was observed for much of the upper valley with water
depths from 2 to 3 inches. In the portion of the valley upstream of the UT6-613 location a distinct
Hell Swamp/Scott Creek Mitigation Site Appendix B-2 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

channel was evident which continued downstream almost to the location of UT6-513 (Video 3_1461,
Photos 14 and 15). By UT6-513, the valley slope flattened and the channel became more distributed in
places; occasionally, the flow was slower and the channel contained more algae but the flow was strong
enough to keep the channel clear of algae in the middle. By the UT6-413 location, low flow was evident
at both the UT6-4A and UT6-4C well locations (2.5 inches of water) but not as evident at UT6-4B location
where the valley elevation is slightly higher.
UT7:
February 2015 survey: low to moderate flow was observed from the vicinity of UT7-313 (Videos 4_1450,
Video 5_1451, and Video 6_1454) to UT7-213, high flow was observed at UT7-113, and water depths
ranged from 2 to 6 inches. Between UT7-313 and -213, there were some areas of denser vegetation
where flow was lower and more difficult to observe, but by -213 location, flow had become moderate
and easily detected and was continuous to its junction with UT6.
UTS:
October 2014: No visible flow with dense Juncus sp.; however, in winter, some distance along a flow
path might be more evident in the lower portion of this valley, at least up to the ruts left by construction
equipment. This valley was not surveyed in February.
UT2:
October 2014: No standing water in valley at stream array, no visible flow or signs of flow. Although
when Scott Creek is out of its banks downstream of the single thread, it is apparent that water moves
across the lower portion of this valley.
UT1:
October 2014: Very dense vegetation for entire length of valley, very difficult to see any flowpath or to
walk. More Polygonum sp. and less Mikania than other areas. Two to 3 inches of water in most places
immediately downstream of UT1-213 location; by UT1-113 gauge location, easier walking but still no clear
flow path or evidence of flow. At intersection with Scott Creek single thread channel, no water in UTI
but 3 inches deep in single thread.
UT4:
October 2014: No flow or water at the downstream stream array or below; heavily vegetated. This
valley was not surveyed in 2015.
UT3:
October 2014: No water or evidence of flow into lower Scott Creek swamp (Photo 16) or at stream array
UT3-1B (Photo 17). Narrow flow paths were visible between 2B and 3B flow gage locations, but no
water in flow paths at time of survey; no evidence of flow as in past surveys (no debris packs). Between
3B and 5B flow path continued but no water or evidence of flow as in past surveys (no debris packs)
(Photo 18). This flow path, especially between UT3-4B and -513, has been documented in previous
surveys.
Hell Swamp/Scott Creek Mitigation Site Appendix B-3 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

February 2015: Upstream/west of the stream crossing was surveyed and flow was observed from UT3-
8B location downstream beyond the location of UT3-613 (Video 7_1440 and Video 8 _1443). Water
depths in the western portion of the valley above the constructed stream crossing varied between 2 and
10 inches and flow was moderate at most observation points, with lower flow noted where the flow
path became less constricted, or the herbaceous vegetation was denser, or the valley slope flattened.
UT8:
October 2014: Downstream of stream crossing, channel and flow evident with 1 to 2 inches of water
(line feature collected downstream of UT8-113 location; Photo 19). Vegetation was thick across channel,
but not as congested/choked as in other valleys (more Scirpus and Typha). Apparent short flow path
evident near UT8-213, but no scour or oriented vegetation. At UT8-313 a consistent flow path can be
followed, sometime more evident than others, with no water visible. Between UT8-36 and -46, valley
becomes wider and it is harder to consistently discern the flow way. There is a distinct vegetation
change upstream of UT8-413 (Photos 20 and 21). Approximately 75 feet downstream of UT8-513 a flow
channel is evident which continues upstream beyond -513 for a short distance before it becomes lost in
the vegetation. Between UT8-513 and -613, some channel/flow paths are apparent here and there, but
confidence is not strong.
Hell Swamp/Scott Creek Mitigation Site Appendix B-4 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

LOWER SCOTT CREEK (LSC) 8 OCTOBER 2014
Photo 1. View upstream LSC from vicinity of
property boundary. Two dead trees mark UT6.
Photo 2. View upstream LSC near junction with
UT6.
Photo 3. View upstream near bottom of UT6
where joins LSC (flow visible -see Video 1). Two
dead trees visible in upper center.
Photo 4. View upstream of short feature
feeding into lower Scott Creek, about 100 feet
west of UT6 junction; has been GPSd before and
has been unvegetated; no flow in October
survey.
Hell Swamp/Scott Creek Mitigation Site Appendix B-5 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

Photo 5. View upstream of ponded area against
berm LSC. Water depths 2 to 4 inches.
Photo 7. View downstream of flow path along
filled section of lower Scott Creek where it
rejoins main Scott Creek to the right through a
break in the spoil pile berm.
Photo 6. View upstream lower Scott Creek of
ponded area in filled ditch; swamp to left
beyond the tall cypress at left edge of photo; no
berm here so direct connection between filled
ditch and swamp. No visible flow.
Photo 8. View upstream LSC (LSC Line 1)
ponded area against berm with downstream
entry into swamp at beginning of Line 1 behind
camera to left. Water depths 3 to 6 inches.
Hell Swamp/Scott Creek Mitigation Site Appendix B-6 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

Photo 9. LSC downstream into swamp at
stream crossing of old farm road. Water depth
2- 3 inches, flow very low to none.
Hell Swamp/Scott Creek Mitigation Site Appendix B-7 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

SCOTT CREEK SINGLE THREAD (SC) 8 OCTOBER
2014
Photo 10. View downstream of single thread
channel at SC -313 location (box at left bottom).
UPPER SCOTT CREEK (USC) — FEBRUARY 2015
Review Video 1
Photo 12. View upstream below array 10 (USC-
10B is at pole in left distance) where short
feature joins main channel- moderate flow.
Photo 11. View upstream of single thread
channel at SC -36 location (portion of box visible
at right).
Photo 13. Flow path through accumulated
algae in vicinity of USC -1013.
Hell Swamp/Scott Creek Mitigation Site Appendix B-8 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

UT6 (LOWER OCTOBER 2014, UPPER FEBRUARY
2015)
Review Video 2(Oct) and Video 3 (Feb)
Photo 14. View downstream of flow path
towards UT6-613 (pole in middle of photo),
February 2015.
UT7 (FEBRUARY 2015)
Review Videos 4, 5, and 6. No still photos.
UT3 (OCTOBER 2014 AND FEBRUARY 2015)
Review Videos 7 and 8 (both in Feb)
Photo 16. View downstream into lower Scott
Creek from bottom of UT3; no water in system
at this location. October 2014.
Photo 15. View downstream along flow path
beyond UT6-613 which continues for —200 feet
through Baccharis shrubs and herbaceous
vegetation.
Photo 17. View upstream to UT3-113 (in center
of photo); no water in system at this location.
October 2014.
Hell Swamp/Scott Creek Mitigation Site Appendix B-9 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

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Photo 18. Downstream at UT3-513, flow path
barely visible in photo to left of box and
continues through vegetation to biologist in
center of photo (in yellow shirt). October 2014.
UT8 8 OCTOBER 2014
Review Video 9
Photo 19. View downstream from constructed
stream crossing, UT8-113 in middle distance; UT8
Line 1 feature GPSd. Water depths 1 to 2
inches, very low flow, but channel visible. Too
much vegetation to determine channel in
middle segment of this photo; Line 1 channel
continues upstream of the crossing for a short
distance, but no water upstream of crossing.
Photo 20. UT8 upstream at 46 very different
vegetation than downstream of 46 (Photo 21).
Hell Swamp/Scott Creek Mitigation Site Appendix B-10 PCS Phosphate Company, Inc.
Fifth Annual and Summary Report February 2016

Photo 21. UT8 downstream at 4B.
Hell Swamp/Scott Creek Mitigation Site Appendix B-11
Fifth Annual and Summary Report
PCS Phosphate Company, Inc.
February 2016