Impacts of the Waukesha Water Diversion on the Baseflow of the Fox River in Wisconsin

Patrick Siwula and Jason Tutkowski

University of Wisconsin-Milwaukee

CES 651 Stream Management and Restoration

December 2016

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Table of Contents

Abstract………………………………………………………………………………………....2

Introduction……………………………………………………………………………….…....3

Methods………………………………………………………………………………………..11

Results……………………………………………………………………………………...….15

Discussion…………………………………………………………………………………….20

Conclusions……………………………………………………………………………….…..23

Acknowledgements……………………………………………………………….…………23

References……………………………………………………………………………............24

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Abstract –

The City of Waukesha, WI receives most of its current public water supply from a

deep sandstone aquifer in which recharge is greatly reduced by the Maquoketa shale

confining layer. Severe drawdown and harmful levels of carcinogenic radium above

federal standards have caused the City to seek a diversion of Great Lakes water to

serve as a new primary public water supply. The Fox River, which flows through

Waukesha, currently receives all of the effluent (approximately 10 million gallons per

day) from Waukesha’s wastewater treatment plant (WWTP). If the diversion obtains all

necessary approvals and permits, then the effluent will be rerouted to the Root River.

This study investigated the impact the rerouting would have on the Fox River in terms of

baseflow reduction, cross-sectional water depth, as well as water quality.

Daily Fox River discharge data (January 1, 1964 through December 31, 2015)

was downloaded from a U.S. Geological Survey stream gage located approximately

4,000 feet upstream of Waukesha’s WWTP. Streamflow Analysis and Assessment

Software was used in order to determine baseflow in the Fox River with and without the

effluent discharged from the Waukesha WWTP. In order to determine the effect of

reduced baseflow on the Fox River, stream cross section and hydrologic data were

obtained from the Wisconsin Department of Natural Resources. The change in water

levels at the cross sections were determined using the Hydrologic Engineering Center

River Analysis System model (HEC-RAS) by editing the model to include baseflow data

both with and without the WWTP effluent. To simplify the data evaluation, five groups of

five cross sections were reviewed out of a possible 513 throughout Waukesha and

Racine Counties. A single cross section was also reviewed along the Wisconsin-Illinois

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state line. Results showed that declines in water surface levels were greatest just

downstream of the WWTP with a grouping average of 2.91 inches and decreased

moving further downstream, with the exception of the grouping between the villages of

Waterford and Rochester, WI. Water surface declines were found to be zero at the

Wisconsin-Illinois state line. It is unlikely that in-stream habitat will be overly affected by

these small declines, however, all reductions in baseflow need to be considered as part

of management programs moving forwards. Continued monitoring will be required to

validate the results put forth in this study to continue assessing how the Waukesha

diversion will impact the Fox River.

Introduction –

Waukesha Water Diversion.

The city of Waukesha is located at approximately 43°00′42″N 88°13′54″W

(Google, 2016) in Township 6 North and Range 19 East in Waukesha County,

Wisconsin (Waukesha County, 2009). The city spans 25 square miles and is home to

an estimated 71,970 residents (U.S. Census Bureau, 2015). Located in Southeastern

Wisconsin, the city receives ample precipitation at around 34.62 inch per year (U.S.

Climate Data, 2016). But despite having a relatively wet climate, Waukesha has had

some major water use issues.

In order to keep pace with a growing population, between 1935 and 2009

Waukesha constructed 11 groundwater wells to meet its water use demands

(Chowdhury et al. 2013). Waukesha relies on deep aquifer wells for 87 percent of its

public water, which are supplemented by shallow aquifer wells. Groundwater recharge

in the area is restricted due to the Maquoketa shale confining layer that underlies the

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city (Waukesha Water Utility, 2016). Water use and restricted natural recharge have

both led to water levels in the deep sandstone aquifer declining 500 to 600 feet since

the late 19th century (CH2M HILL, 2012). Water in the deep aquifer also contains high

levels of carcinogenic radium that have been increasing in concentration due to

declining water levels (WDNR, 2016a). These levels have reached up to 15 pCi/L

(picocuries per liter) (Waukesha Water Utility, 2016), three times higher than the Safe

Drinking Water Act standard of 5 pCi/L for combined radium 226/228 (EPA, 2016). In

2009, the State of Wisconsin ordered Waukesha to bring their drinking water quality into

radium compliance by June 30, 2018 (CH2M HILL, 2012).

Water supply options to address both high radium and declining aquifer water

levels have been worked on by the city and the Southeastern Wisconsin Regional

Planning Commission (SEWRPC) for the past two decades. SEWRPC’s final

consensus was that Lake Michigan would be the best option for Waukesha’s current

and future water requirements (CH2M HILL, 2012). While Waukesha is situated only 17

miles west of the sizeable surface waters of Lake Michigan and the Laurentian Great

Lakes (WDNR, 2016a), Waukesha has not been able to easily utilize these water

resources. The Great Lakes–St. Lawrence River Basin Water Resources Compact

(also referred to as the Great Lakes Compact) prohibits diversions out of the Great

Lakes Basin. Waukesha is located about 1.5 miles west of the Great Lakes surface

water divide and is defined as a city within a straddling county, having a portion of its

area inside Lake Michigan’s watershed.

Fourteen initial water supply options were considered, however, eight were

eliminated in the initial screening process due to major environmental and regulatory

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issues. That left six water supply options which were further evaluated (Waukesha

Water Utility, 2016). Options included using 1) a combination of deep and shallow

aquifer water, 2) shallow aquifer with Fox River alluvium, 3) Lake Michigan (City of

Milwaukee), 4) Lake Michigan (City of Oak Creek Alignment 1), 5) Lake Michigan (City

of Oak Creek Alignment 2), and 6) Lake Michigan (City of Racine). The severity of

environmental impact on the groundwater, geomorphology and sediments, flooding,

aquatic habitat, water quality, wetlands, and soils varied between the options.

Environmental impact analysis on each of the six major options showed that

groundwater options in the Mississippi River Basin would not be protective of public

health and the environment and would have a potential to greatly impact hundreds of

acres of wetlands and several seepage lakes (CH2M HILL, 2013a).

Due to the impacts caused by utilizing water resources within the Mississippi

River Basin, the proposed plan focused on obtaining water from the Lake Michigan

Basin. Waukesha sought an exception from the prohibition of diversions under the

Great Lakes Compact and its companion the Great Lakes–St. Lawrence River Basin

Sustainable Water Resources Agreement. Diversions are prohibited under the

Compact and Agreement with very limited exceptions. One exception allows a

community within a straddling county, like Waukesha, to apply for a diversion of Great

Lakes water. The final proposed project included an average daily demand of 10.1 mgd

and maximum daily demand of 16.7 mgd from Lake Michigan via pipeline alignment 2

through the City of Oak Creek. Return flow would be to the Root River via pipeline

alignment 2, which would be sufficient for growth in Waukesha’s planned service area

through 2050. The City of Oak Creek obtains its water from Lake Michigan and treats it

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to drinking water standards. A pipeline and pump station would be constructed in order

to convey the treated water to Waukesha. The proposed pipeline would be 30 to 36

inches in diameter, 19.4 miles in length, and would connect Oak Creek’s water

distribution system to the Hillcrest drinking water reservoir in Waukesha. The pipeline

would follow rights-of-way in order to minimize environmental impacts. Once Waukesha

receives Lake Michigan water they would no longer use their groundwater supply wells,

however they would still maintain them for emergency purposes (CH2M HILL, 2013a).

Return flow would be in the form of treated wastewater from Waukesha’s

wastewater treatment plant and would be equal to the volume of withdrawal minus the

volume of consumptive use. A pipeline and pump station would be constructed in order

to convey the treated wastewater to the Root River in Franklin, WI. Any water use over

the maximum daily demand would be discharged to the Fox River. Waukesha’s

wastewater treatment plant includes activated sludge with a tertiary dual media filtration

of anthracite and sand with ultraviolet light disinfection. The plant has consistently met

its state and federal permits for biochemical oxygen demand (BOD), total suspended

solids (TSS), ammonia (NH3-N), and total phosphorus (TP). A 20 year facilities update

plan identified provisions for improvements to the UV disinfection system and

reaeration. The proposed return flow pipeline would be 30 inches in diameter, 20.2

miles in length, and would track alongside the supply water pipeline for the majority of

its length (CH2M HILL, 2013a).

As of June 21, 2016, the Great Lakes-St. Lawrence River Basin Water

Resources Council approved Waukesha’s diversion application under two major

conditions: 1) The initial request for an average daily demand of 10.1 mgd would be

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reduced to 8.2 mgd and 2) The original water service area be reduced to only i)

incorporated land within the boundaries of the City of Waukesha and land outside the

City of Waukesha’s jurisdictional boundaries that are served with municipal water by the

Applicant through the Waukesha Water Utility as of May 18, 2016 and ii) land lying

within the perimeter boundary of the City of Waukesha that is part of unincorporated

land in the Town of Waukesha. Under those conditions, the governors of each of the

eight Great Lakes states unanimously approved the diversion of Lake Michigan water to

the City of Waukesha (Water Resources Council, 2016). After that final major hurdle,

Waukesha could begin to pursue all government permits after which the Wisconsin

Department of Natural Resources (WDNR) would give final approval (WDNR, 2016a).

Any water withdrawn from the Lake Michigan watershed, per the framework set

forth in the diversion, must be returned to the watershed at a volume equal to the

volume of withdrawal minus the volume of consumptive use (CH2M Hill, 2013a). This

volume of water returning to Lake Michigan will be entirely composed of treated

wastewater and must be piped into a tributary in the watershed in order to return to the

Lake. The City of Waukesha’s proposed return flow plan has outlined several options for

locations to return water to Lake Michigan, with the preferred location being the Root

River, which rises in Waukesha County, flows through Milwaukee and Racine Counties,

and empties into Lake Michigan at the City of Racine (CH2M Hill, 2013b; WDNR, n.d.).

The Root River was chosen as the preferred option for returning flow to Lake Michigan

due to having similar size and watershed characteristics as the Fox River, where all of

the City of Waukesha’s wastewater currently flows into (CH2M HILL, 2013b). The

diverting of Waukesha’s wastewater into the Root River presents several management

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challenges that must be met regarding both the quantity and quality of water being

diverted. Many of these challenges have been discussed as they pertain to the Root

River, however, relatively little has been done to assess the potential impacts to the Fox

River once the diversion is completed. The focus of this study is to assess the impacts

to the Fox River that the rerouting of the City of Waukesha’s wastewater to the Root

River will have in terms of baseflow reduction, cross-sectional water depth, as well as

water quality.

Fox River Watershed Characteristics.

The Fox River is located within the Upper, Middle and Lower Fox River

watersheds, which cover a total area of 513 square miles. The Upper Fox River

Watershed is 151 square miles in area and is located in Washington and Waukesha

Counties. The Fox River runs 24.5 miles through this area. The watershed is primarily

agricultural (37%) and urban (30%), although 11% is wetland, of which only 54% of the

original extent of wetlands still exist. Most stretches of the Fox River are impaired for

either degraded habitat, contaminated fish tissue, low dissolved oxygen, or degraded

biological communities. Pollutants include suspended solids, PCBs, and total

phosphorus. Most of the City of Waukesha is in this watershed, which pumps extensive

amounts of groundwater from its deep sandstone aquifer (WDNR, 2010).

The Middle Fox River Watershed is 248 square miles in area and is located

throughout Waukesha, Milwaukee, Racine, and Walworth Counties. The Fox River runs

20.1 miles through this area. The watershed is primarily agricultural (41%) with 18%

grassland, 14% wetlands, and 13% forest. Urban accounts for only 4% of all land uses.

Genesee Creek is considered an exceptional resource water and Spring Lake is

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considered an outstanding resource water. The Vernon Marsh Wildlife Area is also

located in this watershed and has the potential to be greatly impacted by water supply

alternatives to the Great Lakes water diversion from the City of Waukesha. All stretches

of the Fox River in this watershed are also impaired. Impairments include excessive

algal growth, contaminated fish tissue, degraded biological communities, degraded

habitat, and low dissolved oxygen. Pollutants include total phosphorus, PCB’s, and

suspended solids (WDNR, 2014).

The Lower Fox River Watershed is 114 square miles in area and stretches

through Racine, Kenosha, and Walworth Counties. The Fox River runs 38.1 miles

through this area. This watershed is also primarily agricultural (47%), with forests

covering 15%, wetlands 13%, and grasslands 11%. Less than 2% of the land cover is

urban. One stretch of the Fox River is impaired for contaminated fish tissue and

degraded biological communities. Pollutants include PCBs and total phosphorus. The

Fox River in this watershed is at its largest Wisconsin extent and is greatly impacted by

agriculture and drain tiles. Bank erosion and flashy water levels can both be issues

(WDNR, 2002).

Current Wastewater Practices.

Currently, the Fox River receives all of the effluent from Waukesha’s wastewater

treatment plant (WWTP), which ranges between 9-12 mgd with an average of 10 mgd,

(CH2M HILL, 2010). This practice has been in place since 1890 and the presence of

WWTP effluent in the river represents a significant portion of the flow in the Fox River,

which has an average discharge of just above 72 mgd (CH2MHILL, 2013b; USGS,

2016). The effluent leaving the WWTP has been described as high quality, and

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consistently meets parameters set out in the facilities National Pollutant Discharge

Elimination System (NPDES) permits (CH2M HILL, 2010) (Table 1). While this effluent

does have high quality, its presence or absence alone represents a water quality

management challenge in terms of constituent ratios and biotic integrity.

Significance of the Problem.

The re-routing of this effluent to the Root River, per the plan set out in the

diversion, will represent not only a reduction in baseflow to the Fox River, but also a

reduction in the constituents present in the River, such as TSS and phosphorus. These

reductions in baseflow and constituent load may cause changes to the Fox River in

terms of water depth, habitat availability, and water quality. Additionally, there may be

impacts to other areas in Waukesha County downstream of the treatment plant, such as

Table 1. Waukesha WWTP average monthly effluent constituent concentrations (CH2MHILL, 2010).

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the Vernon Marsh, which consists of wetlands and flowages along the Fox River

(WDNR, 2016b). There also is the potential for a reduction in assimilative capacity, or

the capacity to receive waste waters or toxic substances without deleterious effects and

without damage to aquatic life, of other downstream reaches of the Fox River itself. The

following analyses were undertaken in order to address these, and other issues arising

from the diversion of Waukesha’s wastewater.

Methods –

Stream gage discharge data was downloaded from the U.S. Geological Survey’s

(USGS) database for one gage site in the City of Waukesha, WI on the Fox River. The

site retains a unique identifier site number of 05543830, a hydrologic unit code of

07120006, global positioning system coordinates of 43°00'17" N latitude, 88°14'37" W

longitude (43.004722, -88.243611), and is positioned on the left bank of the Fox River

40 ft downstream from the Prairie street bridge in downtown Waukesha (USGS, 2016).

This gaging station is located roughly 4,000 feet upstream from the Waukesha

Wastewater treatment plant, which discharges its effluent directly into the Fox River

(Figure 1; City of Waukesha, 2011). This point on the Fox River drains an area of 126

mi2 (326.3 km2) (USGS, 2016).

Daily average discharges in units of cubic feet per second (cfs) beginning

January 1, 1963 and ending November 7, 2016 were obtained as a Microsoft Notepad

and transferred to Microsoft Excel. The data was then formatted in order to be put into

the Streamflow Analysis and Assessment Software (SAAS) stream management

software program version 4.1 (Metcalfe and Schmidt, 2016). Leap days were removed

from the data, units were converted to cubic meters per second (cms), and the time

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range was shortened to January 1, 1964 through December 31, 2015. Since the gaging

site was located upstream from the Waukesha WWTP, two separate files were created,

one for discharge data with an additional 10 mgd (roughly 15.47 cfs or 0.438 cms)

effluent and one without the effluent to simulate the Waukesha WWTP effluent

discharge to the Fox River before and after the diversion. The data was then

highlighted and saved separately as comma separated value files (csv).

The daily discharge data was then put into the SAAS stream management tool in

order to determine baseflow in the Fox River with and without the effluent discharged

from the Waukesha WWTP by having the software conduct a baseflow separation

analysis. More information on SAAS can be found at Metcalfe et al. (2013). The

outputs from SAAS were Microsoft Notepad files of baseflow (cms) with and without

effluent from February 2, 1964 through November 30, 2015. The baseflow data was

then moved to one Microsoft Excel file and units were converted to cfs. The baseflow

Figure 1. Location of USGS Fox River gauging station in relation to Waukesha WWTP. Distance

between the two is ~4,000 ft. (Google Earth, 2016).

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data was then put into JMP Pro 12 predictive analytics software in order to display the

data visually. A box plot graph was created of baseflow with and without effluent,

separated by month, and placed side by side for comparison. More information on JMP

can be found at SAS Institute (2016).

In order to determine the effect of reduced baseflow on the Fox River, stream

cross section and hydrologic data were obtained from WDNR as a Hydrologic

Engineering Center River Analysis System (HEC-RAS) file as well as a geographic

information system (GIS) shapefile (WDNR, 2016c). ArcMap 10.4.1 was used to view

the GIS data in order to locate the cross sections spatially and match them with a

unique identifier in the HEC-RAS file. More information on GIS can be found at ESRI

(2016).

HEC-RAS 4.1 was used to open the HEC-RAS file and display the cross

sectional information. The change in water levels at the aforementioned cross sections

was determined by editing the model to include baseflow data both with the WWTP

effluent and without the WWTP effluent. A steady flow analysis was run using only this

baseflow data in order to show differences in cross-sectional water depth based on the

presence or absence of the WWTP effluent. Identifiers were matched from the GIS

data and 26 cross sections were reviewed out of a possible 513.

Five groups of five cross sections were chosen (Figure 3). Four of the groupings were

located in Waukesha County just downstream of the Waukesha WWTP, between

Highway 59 and County Road H, along Vernon Marsh, and just north of the

Waukesha/Racine County line. The fifth grouping was located in Racine County just

south of Waterford, WI. Additionally, the last cross section in Wisconsin before the Fox

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Figure 3 Map of cross sections along the Fox River.

River enters Illinois was also chosen. More information on HEC-RAS can be found at

USACE (2016).

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Results –

Results from SAAS baseflow separation analysis can be seen in Tables 2 and 3

showing differences in discharge with and without Waukesha WWTP effluent.

Fox River Averaged Monthly Baseflow With Effluent (cfs)

Month BFI 25th Percentile

(75% Exceedance) Median (50% Exceedance)

75th Percentile (25% Exceedance)

January 0.6795 47.15 58.98 72.50

February 0.5872 47.71 63.50 81.54

March 0.4891 65.97 97.72 132.18

April 0.5295 88.39 117.49 156.83

May 0.5693 64.77 85.57 117.88

June 0.4831 45.94 59.54 89.77

July 0.5616 38.10 49.19 67.52

August 0.5690 33.65 44.46 56.72

September 0.5637 33.27 43.90 60.25

October 0.6552 38.46 52.76 69.85

November 0.6614 47.78 60.21 78.79

December 0.6504 46.51 60.81 79.56 Table 2. Monthly baseflow index values (BFI) and averaged baseflow from January 1, 1964 through

December 31, 2015 with effluent provided from the SAAS software. The BFI is the ratio between

baseflow and total flow. Therefore a BFI of 0.5 indicates that 50% of total streamflow can be attributed to

baseflow for the respective time period.

Fox River Averaged Monthly Baseflow Without Effluent (cfs)

Month BFI 25th Percentile

(75% Exceedance) Median (50% Exceedance)

75th Percentile (25% Exceedance)

January 0.5953 28.57 40.40 53.93

February 0.5060 29.10 44.92 62.97

March 0.4399 47.36 79.14 113.61

April 0.4910 69.82 98.92 138.26

May 0.5161 46.19 66.99 99.30

June 0.4105 27.33 40.97 71.19

July 0.4693 19.53 30.58 48.95

August 0.4497 15.08 25.89 38.14

September 0.4506 14.66 25.32 41.67

October 0.5646 19.88 34.15 51.28

November 0.5822 29.21 41.60 60.21

December 0.5705 27.90 42.20 60.99 Table 3. Monthly baseflow index values (BFI) and averaged baseflow from January 1, 1964 through

December 31, 2015 without effluent provided from the SAAS software. The BFI is the ratio between

baseflow and total flow. Therefore a BFI of 0.5 indicates that 50% of total streamflow can be attributed to

baseflow for the respective time period.

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Statistical output from SAAS was input into JMP (Figure 2) in order to display

statistical data as a box plot to graphically display differences in discharge with and

without Waukesha WWTP effluent.

Figure 2. Box plot of Fox River baseflow with and without effluent discharged from the Waukesha WWTP

using data from SAAS and displaying it in JMP.

Results of the HEC-RAS steady flow analysis using edited baseflow data were

obtained for the 26 selected cross sections in 6 groupings downstream of the

Waukesha WWTP. Declines in water surface were obtained from elevation data in the

HEC-RAS graphical cross section representations and average differences in water

surface decline were calculated for each grouping and for all 26 together. Average

declines in water surface level were the greatest just downstream of the WWTP at 2.91

inches and decreased moving further downstream, with the exception of the grouping

between Waterford and Rochester, WI (Table 4). Water surface declines were found to

be zero at the Illinois state line; this cross section was omitted from the overall averages

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so as to not skew the results (Table 4). One graphical representation from each of the

groupings was selected to be shown in order to illustrate the water surface level

declines (WS), the energy head declines (EG), as well as the declines in critical flow

(Crit) for baseflow with and without effluent from the WWTP (Figure 4).

Cross section 315328 (Just downstream of WWTP).

Cross section 303861 (Between Hwy 59 and CTR H).

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Cross section 263404 (Vernon Marsh Area).

Cross section 177822 (North of Waukesha County Line).

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Cross section 136828 (Between Waterford and Rochester).

Cross section 617 (At Illinois State line).

Figure 4. Graphical representations of selected cross-sections from each grouping.

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Location Cross-section

Water Surface

with Effluent (ft)

Water Surface without Effluent

(ft)

Difference (ft)

Difference (in)

Average Difference

within Groupings

(in)

Just Downstream

of WWTP

317652 786.91 786.69 0.22 2.64

316516 786.49 786.28 0.21 2.52

315328 786.08 785.84 0.24 2.88

314594 785.86 785.59 0.27 3.24

313294 785.63 785.37 0.26 3.12 2.91

Between Hwy 59 and

CTR H

307084 784.93 784.7 0.23 2.76

305041 784.28 784 0.28 3.36

303861 784.04 783.79 0.25 3

302506 783.89 783.66 0.23 2.76

301419 783.86 783.65 0.21 2.52 2.88

Vernon Marsh Area

263404 778.47 778.2 0.27 3.24

259836 778.21 777.97 0.24 2.88

255515 777.99 777.8 0.19 2.28

252534 777.84 777.67 0.17 2.04

249100 777.73 777.58 0.15 1.8 2.45

North of Waukesha

County Line

183684 773.52 773.46 0.06 0.72

182126 773.52 773.45 0.07 0.84

180732 773.51 773.45 0.06 0.72

179108 773.52 773.45 0.07 0.84

177822 773.51 773.44 0.07 0.84 0.79

Between Waterford

and Rochester

138673 763.61 763.46 0.15 1.8

137958 763.32 763.18 0.14 1.68

136828 763.17 763.04 0.13 1.56

135563 762.96 762.87 0.09 1.08

134512 762.31 762.13 0.18 2.16

Average: 2.13 1.66

At Illinois State Line 617 742.5 742.5 0 0

Table 4. Declines of water levels in individual cross sectional groupings.

Discussion –

Effects on physical and biological components of Fox River.

Based on the aforementioned results of reduction in baseflow to the Fox River

resulting from the Waukesha Diversion and associated rerouting of wastewater to the

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Root River, there are several considerations in regards to the overall health of the

system which are outlined below.

River systems are complex and change temporally and spatially across the

landscape (Vannote et al. 1980). Streamflow can have a profound effect on both the

physical and biological components of the stream system. Stream flow helps dictate the

shape of the river, its size, habitat, and the distribution, abundance, and diversity of

aquatic species (Bunn and Arthington, 2002). A change in the rates of water level

fluctuations, the intensity of these fluctuations, and frequency can have profound effects

on seedling survival rates and plant growth rates. Decreases in flows leading to

reduced inundation of floodplains can also reduce recruitment of fish, decrease aquatic

bird richness and abundance, and cause declines in wetland plant species (Bunn and

Arthington, 2002). Reduced discharge was also shown to increase coarse particulate

organic matter retention and decrease travel distance in streams. Decreased water

levels, which lead to greater protrusion of rocks, boulders, and woody debris, also

generally make riffles more effective at retaining CPOM (Dewson et al. 2007). A

decrease in baseflow can also lead to more shallow areas in the stream, which can

increase in temperature more readily and can lack complex structure (Richards et al.

1996). This was corroborated in a study by Dewson et al. (2007) which observed

reduced invertebrate densities in streams with reduced flows.

Effects on assimilative capacity of Fox River.

Assimilative capacity of a stream generally refers to its ability to receive toxic

substances or wastewater without causing damage to aquatic life or humans. Different

definitions are used throughout the scientific community, however, a focused definition

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used by chemists and wastewater scientists specifies assimilative capacity as the

volume of waste that may be discharged to a body of water without lowering its ambient

dissolved oxygen concentration below a predetermined value (Campbell, 1981). The

City of Waukesha’s planned Great Lakes water diversion would result in approximately

10 mgd less effluent being discharged into the Fox River. The decrease in effluent

discharge would affect baseflow in the Fox River thereby decreasing overall flows as

well. A reduction in in-stream flows can reduce the assimilative capacity of a stream

(Yulianti and Burn, 1997; Poole and Berman, 2001). Other processes that affect

baseflow and can lead to reduced assimilative capacity include reduced phreatic

groundwater discharge, low flow periods due to climate, and reduced stream structure

leading to reductions in hyporheic water flows (Poole and Berman, 2001). This can

result in increased water treatment costs in order to maintain water quality standards

(Yulianti and Burn, 1997). Alternatively, a decrease in effluent could also increase biotic

health due to a decrease in suspended solids, total phosphorus, bacteria, and emerging

pollutants.

WWTP effluent has been shown to alter sex steroid hormone levels in juvenile

and adult fish, impair gonadal development and sexual differentiation in early life

stages, as well as alter induction of the egg yolk precursor protein, vitellogenin (Thorpe

et al. 2005). Additionally, the presence and interactions between pharmaceutical

products, emerging contaminants, wastewater derived transformation products, and

biotic communities are relatively poorly understood (Cwiertny et al. 2014). These types

of constituents are often present in WWTP effluent and in the case of the Fox River,

may have been impacting the biotic community in ways that have not been quantified,

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regardless of the fact that the WWTP effluent has been consistently described as high

quality (CH2M Hill, 2010) (Table 1). The removal of the WWTP effluent from the Fox

River has the potential to actually improve the biotic community by alleviating some of

the contaminant load and thus improving the water quality. Further studies in the

interactions between pharmaceuticals, emerging contaminants, and their impacts are

needed to explore this phenomenon.

Conclusions –

The results presented here indicate that the baseflow of the Fox River will be

most impacted just downstream of the WWTP with an average baseflow water surface

decline of nearly 3 inches. Moving further downstream, the water level declines drop

and eventually reach zero at the Wisconsin-Illinois state line. It is likely that in-stream

habitat will not be overly affected, however, these declines in baseflow need to be

considered as a part of further management programs moving forwards. Continued

monitoring will be required to validate the results put forth in this study and to continue

assessing how the Waukesha diversion will impact the Fox River.

Acknowledgements –

We would like to thank Christopher Olds, floodplain engineer with the Wisconsin

DNR, for providing us with the HEC-RAS model for the Fox River and associated GIS

data. We would also like to thank Dr. Neal O’Reilly for guidance in working through the

various programs which were used to analyze the data.

24

References

Bunn, S. E., & Arthington, A. H. (2002). Basic principles and ecological consequences

of altered flow regimes for aquatic biodiversity. Environmental management,

30(4), 492-507.

Campbell, I. C. (1981). A critique of assimilative capacity. Journal (Water Pollution

Control Federation), 604-607.

CH2M HILL. (2010, April). Wastewater Treatment Plant Improvements for Returning

Water Withdrawn from Lake Michigan. Retreived from Environmental Report:

http://dnr.wi.gov/topic/wateruse/documents/waukesha/appendix_e.pdf

CH2M HILL. (2012, February). City of Waukesha Water Supply. Retrieved from

Environmental Report:

http://dnr.wi.gov/topic/WaterUse/documents/Waukesha/WaukeshaWaterSupplyE

nvironmentalReport2012-1.pdf

CH2M HILL. (2013a, October). City of Waukesha Environmental Report for Water

Supply Alternatives. Retrieved from City of Waukesha Water Utility:

http://apps.ci.waukesha.wi.us/Files/5_City_of_Waukesha_Environmental_Report.

pdf

CH2M HIll. (2013b, October). City Waukesha Return Flow Plan. Retrieved from City of

Waukesha Water Utility:

http://www.waukesha-

water.com/downloads/4_City_of_Waukesha_Return_Flow_Plan.pdf

25

City of Waukesha. (2011, November). City of Waukesha Wastewater Treatment

Process. Retrieved from City of Waukesha: http://www.waukesha-

wi.gov/DocumentCenter/View/1156

Chowdhury, F., Lant, C., & Dziegielewski, B. (2013). A century of water supply

expansion for ten US cities. Applied Geography, 45, 58-76.

Cwiertny, David M., et al. (2014). "Environmental designer drugs: when transformation

may not eliminate risk." Environmental science & technology 48.20: 11737-

11745.

Dewson, Z. S., James, A. B., & Death, R. G. (2007). Stream ecosystem functioning

under reduced flow conditions. Ecological Applications, 17(6), 1797-1808.

EPA. (2016, November 1). Radionuclides Rule. Retrieved from Drinking Water

Requirements for States and Public Water Systems:

https://www.epa.gov/dwreginfo/radionuclides-rule#rule-history

ESRI. (2016). ArcGIS. Retrieved from ArcGIS: https://www.arcgis.com/home/index.html

Google. (2016). Waukesha. Retrieved from Google Maps:

https://www.google.com/maps/place/Waukesha,+WI/@43.0052701,-

88.3093723,12z/data=!3m1!4b1!4m5!3m4!1s0x8805a626948e9757:0xab2da134

61989c95!8m2!3d43.0116784!4d-88.2314813

Karr, J. R. (1981). Assessment of biotic integrity using fish communities. Fisheries, 6(6),

21-27.

Karr, J. R. (1992). Defining and assessing ecological integrity: beyond water quality.

Environmental toxicology and chemistry, 12(9), 1521-1531.

26

Lyons, J., Wang, L., & Simonson, T. D. (1996). Development and validation of an index

of biotic integrity for coldwater streams in Wisconsin. North American Journal of

Fisheries Management, 16(2), 241-256.

Metcalfe, R.A., Mackereth, R.W., Grantham, B., Jones, N., Pyrce, R.S., Haxton, T.,

Luce, J.J., and Stainton, R., 2013. Aquatic Ecosystem Assessments for Rivers

(AEAR). Science and Research Branch, Ministry of Natural Resources,

Peterborough, Ontario. 210 pp. https://www.ontario.ca/document/aquatic-

ecosystem-assessments-rivers

Metcalfe, R.A. and Schmidt, B., 2016. Streamflow Analysis and Assessment Software

(SAAS) (V4.1). [Online] Available: http://people.trentu.ca/rmetcalfe/SAAS.html

Poole, G. C., & Berman, C. H. (2001). An ecological perspective on in-stream

temperature: natural heat dynamics and mechanisms of human-caused thermal

degradation. Environmental management, 27(6), 787-802.

Richards C, Johnson LB, Host GE. (1996). Landscape-scale influences on stream

habitats and biota. Can. J. Fish. Aquat. Sci. 53: 295-311

SAS Institute. (2016). JMP Pro. Retrieved from JMP Statistical Discovery from SAS:

http://www.jmp.com/en_us/software/predictive-analytics-software.html

Thorpe, K. L., et al. (2005). "Health effects in fish of long-term exposure to effluents

from wastewater treatment works." Environmental Health Perspectives 114, 82-

89.

U.S. Census Bureau. (2015). Waukesha city, Wisconsin. Retrieved from Quick Facts:

http://www.census.gov/quickfacts/table/PST045215/5584250,00

27

U.S. Climate Data. (2016). Climate Waukesha. Retrieved from U.S. Climate Data:

http://www.usclimatedata.com/climate/waukesha/wisconsin/united-

states/uswi0723

USACE. (2016). HEC-RAS. Retrieved from Hydrologic Engineering Center:

http://www.hec.usace.army.mil/software/hec-ras/downloads.aspx

USGS. (2016, November 19). USGS Surface-Water Data for Wisconsin. Retrieved from

National Water Information System: Web Interface:

http://waterdata.usgs.gov/wi/nwis/sw

Vannote, R. L., Minshall, G. W., Cummins, K. W., Sedell, J. R., & Cushing, C. E. (1980).

The river continuum concept. Canadian journal of fisheries and aquatic sciences,

37(1), 130-137.

Water Resources Council. (2016, June 21). Final Decision. Retrieved from City of

Waukesha Diversion Application: http://www.waukeshadiversion.org/ and

http://www.waukeshadiversion.org/media/1825/waukesha-final-decision-of-

compact-council-6-21-16.pdf

Waukesha County Department of Parks & Land Use. (2009). 2009 Land Atlas and Plat

Book. Retrieved from Waukesha County:

https://www.waukeshacounty.gov/uploadedFiles/Media/PDF/Parks_and_Land_U

se/Planning_and_Zoning/Plat_Book/2009%20Waukesha%20WI%20Plat%20Boo

k.pdf

Waukesha Water Utility. (2016, October 26). Waukesha Application. Retrieved from

Waukesha Water Utility: http://waukeshaapplication.com/

28

WDNR. (n.d.). Root Pike Watershed Basin. Retrieved from

http://dnr.wi.gov/water/basin/rootpike/

WDNR. (2002). Watershed – Middle Fox River – Illinois (FX02). Retrieved from

Wisconsin Department of Natural Resources:

http://dnr.wi.gov/water/watershedDetail.aspx?code=FX02&Name=Lower Fox

River - Illinois

WDNR. (2010). Watershed – Upper Fox River – Illinois (FX07). Retrieved from

Wisconsin Department of Natural Resources:

http://dnr.wi.gov/water/watershedDetail.aspx?code=FX07&Name=Upper Fox

River – Illinois

WDNR. (2014). Watershed – Middle Fox River – Illinois (FX04). Retrieved from

Wisconsin Department of Natural Resources:

http://dnr.wi.gov/water/watershedDetail.aspx?code=FX04&Name=Middle Fox

River - Illinois

WDNR. (2016a, June 21). City of Waukesha water diversion application. Retrieved from

Waukesha Diversion Application:

http://dnr.wi.gov/topic/WaterUse/waukesha/diversionapp.html

WDNR. (2016b, September 20). Vernon Wildlife Area. Retrieved from Wisconsin DNR:

http://dnr.wi.gov/topic/lands/wildlifeareas/vernon.html

WDNR. (2016c, November 21). Fox_RAS.zip [Computer File] and FOX_XS.zip

[Computer File]. Madison, WI. Received from Chris Olds, personal

communication, Nov. 21, 2016 [Accessed 11/23/16].

29

Yulianti, J. S., & Burn, D. H. (1997). Investigating links between climatic warming and

low streamflow in the Prairies region of Canada. Canadian Water Resources

Journal, 23(1), 45-60.