Otter Creek Monitoring Report, 2003-2005

By: Becca Spaeth, Michelle Washebek, Meg Marshall, Jared Pierce, Mike Schwartz, Sara Schmidt

Introduction

Otter Creek is a 27-mile tributary of the Eau Claire River with headwaters in the townships of Clear Creek and Otter Creek. It runs along Interstate Highway 94 and 53, then flows north along 53, feeding into the Eau Claire River on the east side of Eau Claire in Altoona. It parallels the corridor for the new Highway 53 bypass, which began construction in the spring of 2004. Otter Creek is classified as a Class III Brown Trout Stream.

In May of 2004, A River Protection Plan for Otter Creek was put together by the collaborative efforts of a number of organizations and individuals. It assessed a number of different water quality indicators including stream conditions, sources of pollution, affects on the fishery, and a non-point source inventory (stream bank erosion, animal waste, and hydrologic impacts). This plan outlined water quality objectives for Otter Creek that involve controlling sediment, stormwater flows, thermal discharge, and bacteria sources.

The purpose of this report is to provide baseline and storm event measurements for six sites on Otter Creek. We anticipate that this report will help track changes in Otter Creek resulting from construction on the bypass that it parallels. The three upstream sites (5, 6, 7) are mostly agricultural areas (Figure 2), while sites 1, 2, and 4 are in areas of urban development (Figure 1). It will compare water quality of Otter Creek to that recorded in the River Protection Plan, studied a year prior.

Methods

In 2003, seven sites were chosen for study on Otter Creek under the direction of the Western District of the Wisconsin DNR. In 2004, these sites were slightly modified. A site at the Eau Claire Country Club was removed. Sites remained unchanged from 2004 to 2005. Temperature monitoring, chemical assessments and habitat assessments were completed in 2004 on the sites listed (Table 1).

Table 1. Otter Creek monitoring sites and parameters measured in 2004 and 2005.

Site*	Location	Temp	Habitat Assess.	Baseline	Storm	Bacteria	Pesticides
1	Spooner Ave.	X***	X	X	X	X	X
2	STH 12	X	X	X	X	X
4	CTH AA	X	X	X	X	X
5	CTH I	X***	X	X	X	X
6	Hwy 53**	X	X	X	X	X
7	CTH D	X***	X	X	X	X	X

* Site #3, originally chosen on Hamilton Ave. in Eau Claire, was removed

** The sampling done in 2004 at the HWY 53 site north of the village of Brackett was actually done on Beaver Creek, a small tributary of Otter Creek, about 100m upstream of where it flows into Otter Creek. In 2005 it was just downstream from where Beaver Creek runs into Otter Creek.

***In these three sites, monitoring devices were left in the stream over winter, therefore the data from them is not available for this report.

Figure 1. Map of urban monitoring sites on Otter Creek.

Figure 2. Map of rural monitoring sites on Otter Creek.

Temperature

Continuous temperature monitoring devices (Onset Corporation 75 day HOBOs) were placed in sites 2, 4, and 6 for the duration of the summer months, recording instantaneous temperatures every hour from June until September. TIDBITS (Onset Corporation 365 days) were placed in the other three sites and remain there for the duration of the winter months, to be removed in the spring of 2005.

Macroinvertebrates

Aquatic macroinvertebrates were collected in the spring and fall in two sites. They were collected in a D-frame net, preserved in alcohol, and taken back to the lab for sorting and identification to family. Data was analyzed using the Hilsenhoff Biotic Index (1988) (a qualitative measure of organic loading into the stream), family richness, percent Ephemeroptera-Plecoptera-Trichoptera (EPT), and Margalef’s Diversity Index (using family diversity instead of species diversity). It should be noted that Hilsenhoff scores calculated in 2005 used a modified version of the index that includes a number of families that the original left out. This modified index typically raises the average score by half a point to a point. This index is more up to date and thought to be more accurate. More info can be found at: http://lakes.chebucto.org/ZOOBENTH/BENTHOS/tolerance.html

Chemistry

One baseline event (no rain in the last five days) and two storm samples (during/after over 1 inch of rainfall) were collected in Otter Creek in both 2003 and 2004. The samples were collected in sanitized bottles by methods instructed by Eau Claire City County Health Department officials. Samples were tested by the ECCCHD for metals (lead, copper, and zinc), phosphorus, dissolved phosphorus, and total suspended solids as well as pesticides and bacteria.

Habitat

Stream habitat assessments were completed on six sites of Otter Creek according to methods developed by Simonson and Lyons (1992).

Results and Discussion

Temperature

Figures 3 and 4 show temperatures in three sites on Otter Creek in 2003 and 2004, respectively. Figure 5 shows four sites on Otter Creek in 2005. Table 2 shows mean and maximum temperature comparisons. In all sites, temperatures slightly decreased since the 2003 measurements were taken.

According to these data and the Thermal Criteria outlined by Lyons and Wang (1996), Otter Creek is a cold water stream. Brown trout survival temperatures are met in the stream according to this data (12-19ºC daily optimal mean, 27.2ºC upper limit). However, brook trout will not likely survive (11-16ºC daily optimal mean, 23.8ºC upper limit). Water entering the stream from Beaver Creek (site 6) is considerably warmer than Otter Creek and provides more stressful conditions for fish than sites 2 and 4. As luck would have it one of the year-long tidbits survived, at Spooner Ave. We are able to see an entire year’s worth of temperature monitoring (Figures 6 and 7).

Figure 3. Temperature data collected by Onset Corporation HOBOs
in Otter Creek in Sites 2, 4, and 6 in summer 2003.

Figure 4. Temperature data collected by Onset Coporation HOBOs
in Otter Creek Sites 2, 4, and 6 in summer 2004.

Figure 5. Temperature data collected by Onset Corporation HOBOs
in Otter Creek Sites 7, 5, 2, and 6 during summer 2005.

Figure 6. Temperature data collected by Onset Corporation HOBOs
in Otter Creek Site 1 (Spooner Avenue) during summer 2004.

Figure 7. Temperature data collected by Onset Corporation HOBOs
in Otter Creek Site 1 (Spooner Avenue) during summer 2005.

Table 2. Temperature comparisons from 2003 to 2004 on three sites on Otter Creek.

	OC 2 (STH 12)		OC 4 (CTH AA)		OC 6 (STH 53)
	2003	2004	2003	2004	2003	2004
Max Temp (ºC)	21.8	21.3	21.7	20.7	25.7	24.7
Mean Temp (ºC)	16.7	16.2	16.3	15.5	18.3	17.2

Macroinvertebrates

Hilsenhoff Biotic Index scored showed ranges from “excellent” to “fair” in Otter Creek. The excellent scores were found at sites OC1 and OC2 in the spring. The fair scores came from OC6 and OC7. This indicates that there is more organic pollution in the stream further away from the city, possibly as a result of farm field runoff.

One surprising thing is that every score on Otter Creek decreased in the fall from the spring. This includes both HBI and EPT scores. This could mean that something drastic happened to the creek over the course of the summer of 2005, or more likely, it is following the same general trend found in other streams as well.

Chemistry

The most significant difference in the chemistry tests from 2003 to 2004 were in the tests for lead and phosphorus (see Appendices for all Chemical and Bacteria results and figures). The baseline data in 2004 showed no lead (in 2003 it also tested for very little), but both 2004 storm events tested for more lead than in any sample from 2003. The three sites that were tested for lead were in the lower portion of Otter Creek, in the urban developed area. These increases may be due to changes in land use along the creek. Some possible sources of lead in runoff are automobile residual fluids, paint from houses, and other urban sources. It is also a strong possibility that the changes in lead during runoff are due to the construction of the bypass. The site closest to the bypass construction was STH 12, and that site showed the greatest fluctuation in lead. The other two sites had a strong vegetative buffer between them and the bypass, while the STH 12 site was very close, with high, eroding banks near the construction.

In 2004, there is a surprising difference in phosphorus measurements. Phosphorus is measured in two ways, total phosphorus and dissolved phosphorus. Since phosphorus can be bound to sediment (like clay), phosphorus is often measured by figuring how much phosphorus has become attached to the suspended solids. Dissolved phosphorus measurement provides insight as to how much of the phosphorus entering a stream is from point sources. Streams with high total phosphorus and low dissolved phosphorus levels usually have most phosphorus input from non-point source pollution, like agriculture and urban areas (Fox River Ecosystem Partnership, 2002). In 2003, this difference in total phosphorus and dissolved phosphorus measurements is very obvious in the storm samples, indicating non-point sources such as urban development. However, in 2004, there is no significant difference between the two measurements at any of the six sites. This indicates point sources of phosphorus, such as faulty septic systems, feedlot runoff, and industrial pollution. In 2005, it is planned to perform direct chemical tests on the stormwater outfalls to try to pinpoint the areas of heaviest phosphorus and other chemical loading into the stream.

Bacteria levels in Otter Creek are alarming. According to the ECCCHD, safe moderate levels of E.Coli for recreation (such as swimming) are at 90-150 col/100ml, with a maximum of about 250 col/ml (Farmer, 2005). Baseline levels of E. Coli in Otter Creek are all exceeding this standard, except site #6, which is actually in Beaver Creek (which indicates that the bacteria in Otter Creek is not necessarily coming from smaller tributaries such as Beaver Creek.

The most alarming measurements in Otter Creek are the bacterial levels during runoff events. All sites have levels well over the limit that is safe for human contact, and some have levels in excess of 24000 col/100ml! These levels are dangerous, especially as the creek runs right through some urban areas in residents’ backyards. Near the CTH AA site, there is a swimming area that is frequented by young people on a regular basis in the summer and will be exposed to high levels of contamination. These levels of bacteria can be harmful to the aquatic environment as well. Better land management may help curb bacterial levels in Otter Creek, especially during runoff events.

Habitat

The lower portion of the stream is plagued by highly eroding banks due to urban development, yards, and storm sewers. The sites in the upper portion of the stream recorded better habitat scores (see Table 3). All sites reported poor scores in pool area and fine sediments. CTH AA (site 4), which is near the boundaries of the City of Eau Claire, reported the worst scores, also recording the lowest score for bank erosion.

Table 3. Habitat evaluation summary on Otter Creek Sites.

Site	1 Spooner Ave.	2 Hwy 12	4 CTH AA	5 CTH I	6 Hwy 53 (Beaver)	7 CTH D
Overall Rating	55 Good	55 Good	40 Fair	55 Good	60 Good	65 Good
Riparian Buffer	good	good	good	good	good	good
Bank Erosion	good	excellent	poor	good	good	excellent
Pool Area	poor	poor	poor	poor	poor	poor
Width : Depth	fair	fair	fair	fair	good	good
Riffle : Riffle or Bend : Bend	excellent	good	excellent	excellent	excellent	excellent
Fine Sediments	poor	poor	poor	poor	poor	poor
Fish Cover	excellent	excellent	good	excellent	excellent	excellent
percent riffles	0	56	0	3	0	31
mean width (m)	10.2	9.5	11.0	8.8	3.9	6.3
mean depth (m)	.47	.37	.37	.36	.24	.53
depth of soft sed.	.26	.12	.42	.31	.28	.49
flow (m³/sec)	.891	1.016	.832	.801	.073	.270

During sampling at the STH 12 site (#2), it was observed that silt fences near Hwy 12 were not functioning appropriately. The buffer zone between the construction of the bypass and the stream at this site is not adequate, which most likely contributes greatly to sediment loading in the stream, not only at this site, but at all sites downstream.

In the future, follow-up studies need to be performed to measure other sedimentation changes due to construction and urban development.

Conclusion

Otter Creek has shown minimal change from last year’s River Protection Plan (Parkurst, et. al., 2004). The water quality objectives outlined in the Plan (controlling sediment, stormwater flows, thermal discharge, and bacteria sources in Otter Creek) are vital for the survival of Otter Creek and its watershed. Chemical and bacterial levels, as well as sedimentation in Otter Creek are on the rise, which will eventually spell doom for the stream and the terrestrial and aquatic life it supports. If residents who use Otter Creek, both for recreational and aesthetic pleasure, are concerned about the stream, measures need to be taken immediately to preserve what is left of the creek and its watershed.

References

Farmer, Darryll. January 19, 2005. Verbal.

Fox River Ecosystem Partnership. May 2002. Water Quality Fact Sheet- Phosphorus. http://www.foxriverecosystem.org/phosphorus.htm.

Lyons, J. and L. Wang. 1996. Development and Validation of an Index of Biotic Integrity for Coldwater Streams in Wisconsin. North American Journal Fisheries Management. Vol. 16:241-256.

Simonson, T. and J. Lyons. 1992. Fish habitat evaluation monitoring manual. Wis. Dept. Nat. Res. Madison, Wis.

Acknowledgments

Thanks to Ken Schreiber (Water Resource Specialist), Dan Simonson, and John Sours (Fisheries Biologist) of the Western District of the Wisconsin DNR, as well as Darryll Farmer, director of the Eau Claire City-County Health Department, and Jean Schomisch, supervisor of the Eau Claire County Land Conservation Department for direction, instruction, and guidance in this project..

Appendix 1. Precipitation in summers of 2003 and 2004

Appendix 2. Water chemistry comparisons on Otter Creek (2003 to 2004)

Site	date	Pb (ug/L)	Cu (ug/L)	Zn (ug/L)	Phosphorus (mg/L)	Dissolved Phosphorus (mg/L)	TSS (mg/L)
1	5-29-03 baseline	<037	<20	<41	026	029	14
	6-10-03	1.3	81	<41	1.2	.21	76
	7-15-03	3.0	<20	<41	1.2	0.21	62
	6-28-04 baseline	<0.56	<49	49	0.53	0.25	14
	8-2-04	4.2	<49	<41	0.32	0.29	100
	9-15-04	3.4	<49	<41	0.42	0.38	31
2	5-29-03 baseline	<0.37	<20	<41	0.24	0.23	14
	6-10-03	0.7	80	<41	0.73	0.25	31
	7-15-03	1.4	<20	<41	0.93	0.19	49
	6-28-04 baseline	<0.56	<49	52	0.45	0.28	24
	8-2-04	6.0	<49	<41	0.35	0.35	160
	9-15-04	3.6	<49	<41	0.48