Spatial Coverage and Co-location with Streamflow Gages
The large number of sites sampled by agencies and groups across the state shows good spatial coverage (fig. 1). However, the number of sites co-located with a stream gage to allow for the calculation of loads shows that some major watersheds lack collocation of streamflow and water monitoring (fig. 2). In particular, the Maumee River and Whitewater River watersheds could use additional monitoring. To address the spatial coverage throughout the state, this analysis will focus on the major river basin design of IDEM since it operates the largest monitoring network in the state.
Major River Basins
There are multiple ways of assessing the monitoring networks, such as ecoregions or where streams ultimately drain. However, since IDEM has the most sampling sites in the state, it makes sense to incorporate its existing study design to assess the monitoring networks in Indiana. IDEM uses 9 Major River Basins (MRBs) as the basis for its 9-year rotating basin probabilistic sampling design and this is the focus of this section (fig. 2). The MRBs that comprise IDEM’s sampling strategy are: the (1) Great Lakes tributaries (St. Joseph to Lake Michigan, and Maumee to Lake Erie); the (2) Upper Wabash, (3) Middle Wabash, and (4) Lower Wabash; (5) Kankakee, (6) White and West Fork White; (7) East Fork White; (8) Whitewater, and (9) tributaries to the Ohio River. Another way to assess the spatial coverage of the water quality networks in Indiana is whether MRBs are co-located with a stream gage so that loads can be determined at pour points .
Click on the links below to jump to a specific Major River Basin:
• West Fork White River
• East Fork White River
• Upper Wabash River
• Middle Fork Wabash River
• Lower Wabash River
• Great Lakes Tributaries
• Ohio River and Tributaries
• Patoka River
• Kankakee River
• Whitewater River Basin
Continuously monitored sites
All the networks within the State of Indiana are sampled at fixed frequency, typically monthly to bimonthly, to estimate the chemical conditions in the streams. Although statistically significant trends and a reasonable assessment of water chemistry can be determined with these sampling frequencies, the conditions between the times of discrete samples cannot be determined. Multi-parameter sensors allow for the continuous monitoring (interval frequency is changeable) of important chemical variables such as pH, dissolved oxygen (DO), specific conductance (SC), temperature, and turbidity, which can detail conditions within the stream. Additionally, some of these parameters can be used as surrogates for other important water quality variables. Continuous turbidity in conjunction with discrete phosphorus or suspended sediment sampling can be used to model continuous total phosphorus or suspended sediment concentrations. Continuous nitrate and orthophosphate sensors directly monitor peak concentrations of during runoff events.
Within Indiana, 25 sites are currently monitored continuously (Appendix 2 and fig. 13). The USGS monitors 12 sites, which include seven nitrate, three orthophosphate, and three sediment continuous sites. The Citizens Energy Group in Indianapolis and Purdue University monitors eight and three sites, respectively, for water quality parameters (pH, specific conductance, temperature, and dissolved oxygen). Since 2009, ORSANCO has continuously monitored DO and temperature at two sites. Additionally, at the J.T. Meyers site DO, SC, turbidity, and sestonic chlorophyll are collected.
Figure 13. Map of sites currently being continuously monitored within Indiana.
Sites Capable to Determine Loads
To understand the mass of chemicals transported downstream, both concentration of the chemical and the amount of water in the stream, or discharge, need to be monitored. Concentrations of chemicals alone in streams can be misleading because if there are high concentrations of a chemical such as nitrate in a stream, yet very little water in the stream, the mass or “loads” of nitrate is very low. Therefore, it is important to have key sampling sites co-located with a streamflow gage or close enough so that loads can be determined. The best estimates of annual loads of chemicals occur when the sampling site is located at or close in proximity to the stream gage. In previous studies, a difference between drainage areas of the sampling site and the streamgage of 10 percent was considered close enough to determine loads. Within Indiana there are a total of 153 sites that are within 10 percent difference in drainage areas between the sampling site and the location of the streamflow gage (fig. 14 and appendix 3). For this paper, a total of 71 sites are between 0 and 1 percent difference, which is considered co-located and provides the best estimates for loads. There are 62 sampling sites with between 1-10 percent difference in drainage area ratios that provide good estimates of load. Any sites that have a greater than 10 percent difference in the drainage area ratio are less accurate but could probably be used for coarse estimates of loads. There are nine sampling sites between 10-15 percent and eight sampling sites between 15-20 percent differences in drainage ratios. There are three sampling sites that were slightly above 20 percent.
Figure 14. Location of sampling 153 sites co-located or close enough to USGS stream gages to calculate loads.
Land use within a watershed greatly affects the water quality within the streams. To understand water quality conditions within a stream, an understanding of the environmental setting and inputs within the watershed is needed. Land use and the degree to which hydro-modification has occurred are the most important determinants of water quality. Increased forested lands within a watershed typically indicate better water quality conditions due to lack of disturbance. Urban areas tend to have the most impacted streams because of the many stressors associated with them. Agricultural lands have the widest range of water quality conditions—from very good to heavily impacted—depending upon the type of agriculture and the practices used within the watershed. Understanding land use and hydrology within our network watersheds is critical for both the research as well as management options to improve water quality.
None of the existing sampling sites in any of the networks qualify for “reference” or “least impacted.” Many of the agencies collecting water quality data in their networks are tasked to compare water quality across sites. Which sites are most degraded and need environmental management? Are there high quality sites within Indiana? CWA Section 305(b) requires states to make water quality assessments and provide an Integrated Report of water quality to the U.S. EPA, in even numbered years along with the CWA Section 303(d) List of Impaired Waters that includes waters that do not meet applicable state water quality standards or designated beneficial uses. Once this listing and ranking of impaired waters is completed, states are required to develop Total Maximum Daily Loads (TMDLs) for them according to the state’s priority framework in order to achieve compliance with the water quality standards. To understand the biological condition of a stream or lake it is necessary to have a gradient of conditions from unimpacted—or “reference”—to heavily impacted conditions. The biological community composition changes along this gradient and can show the water quality conditions of the stream. As streams degrade through channelization, sedimentation, dredging, eutrophication, and invasive species among other stressors, the biological community changes through loss of sensitive species to the increase in species that can survive or out-compete other species due to the physical changes (low dissolved oxygen, increased algal biomass, increased sedimentation). Identifying “reference” or “least impacted” watersheds is important to be able to contrast other sampling sites within the state. Having a reference site or sites within the state included in the monitoring networks would benefit all monitoring entities.
There are parts of five ecoregions in Indiana including the Interior Plateau, Eastern Corn Belt and Plains, S. Michigan/N. Indiana Drift Plains, Huron/Erie Lake Plains, and Interior River Lowland. Because the level of agricultural or urban development varies across these ecoregions, the ability to find unimpacted sites is difficult and often the term “reference site” must be changed to “least impacted” to show the best available conditions in an ecoregion.
Recently, IDEM developed a Sampling and Analysis Work Plan for Reference Site Monitoring Project. The objective of this project is to identify and sample reference (least impacted) sites throughout Indiana to provide biological assemblage information with chemical and physical parameters that will be used to refine or validate the index of biotic integrity (IBI) metrics and biological criteria thresholds every ten years. The primary filter used in selecting reference sites is land use criteria such as percent of agricultural or urban areas, impervious surface area, human population density and distribution, road density and crossings, proportion of active mining activities, proportion of protected lands, and proximity to permitted facilities, confined feeding operations, and Superfund sites. In altered watersheds, chemical and in-stream physical habitat data may be used as a secondary filter to select reference sites and develop biological expectations for “least disturbed condition” (best available condition given widespread disturbance) rather than “minimally disturbed condition” (nearly absent human disturbance) or “historical condition” (prior to major industrialization, urbanization, and intense agricultural practices) (Stoddard et. al. 2006).
IDEM Office of Water Quality worked with the U.S. EPA and a contractor, Tetra Tech, in March 2015 to develop a framework and criteria for reference site selection. IDEM provided Tetra Tech with a list of 1,458 sites that were previously sampled for fish and/or macroinvertebrates between 2003 and 2013 for possible reference site selection. Using land use factors as the primary filter, Tetra Tech provided a list of 324 reference sites. IDEM narrowed down the list further by using in-stream chemical and physical data as a secondary filter. A minimum of 20 reference sites is required in each of the natural environmental gradient classifications (ecoregion, stream size, etc.) to develop linear regression models showing change in biological assemblage structure given certain explanatory variables; increasing the number of reference sites, however, reduces variability in calibrating the IBI and setting biological criteria thresholds (USEPA 2013, Tetra Tech personal communication). Based on the spatial distribution of the sites and available resources, IDEM is conducting site reconnaissance and sampling of reference sites with the goal of at least 20 reference sites each year over the next ten years to refine biological indices, water quality criteria, and possibly develop other assessment indicators and thresholds. Sampling for this project began in April 2015.
Table 1. List of 2016 potential reference sites for the Western Central Basin.
Characterization of land use
Indiana is a heavily agricultural state and the environmental setting for the sampling sites reflects this characterization. Overall, the median land use is 68.0 percent agriculture, 9.3 percent urban, and 7.5 percent forest (table 4). Of the 312 sampling sites, 105 sites have greater than 75 percent agriculture within the watershed and 208 sites have greater than 50 percent agriculture. Many studies use 25 percent as a cutoff of a watershed to be considered urban and there are 57 sites following this rule; furthermore, there are 30 sites above 60 percent and 20 sites above 90 percent urban land use. All, except one site with 60 percent urban land use, are smaller watersheds (less than 70.7 square kilometers). Once the percent urban is relaxed to 25 percent, larger watersheds can be found. There are 11 sites with at least 50 percent forest in the watershed and 38 sites with 25 percent forest. Some of these heavily forested watersheds could be potential reference sites. Many of these forested sites tend to be larger sites, such as the Ohio and White River watersheds.
Sites with duplicate sampling
Each agency collects water quality data for different reasons based upon its water management objectives or mandates. These mandates range from regulatory, such as IDEM which has specific quality assurance and chain-of-custody requirements, to research level, such as the USGS or the universities. Each agency collects different parameters and uses different labs which often have different reporting levels for these parameters. However, sites with multiple agencies collecting data at the same location indicate a redundancy that could be addressed to allow agencies to put funds to use at other sites. Additionally, these agencies could work together to:
- 1) expand the frequency of sampling;
2) coordinate some replicate samples so the data could be used for their respective needs; or
3) increase the amount of quality assurance so that the data could be used by other agencies to improve the quality and quantity of available data for analysis.
There are a total of 18 sampling sites that are monitored by at least two agencies and one site where three agencies sample (table 3, appendix 4, and fig. 15). In particular, the Citizens Energy Group and Marion County Public Health Department (MCPHD) have five co-located sites; MCPHD and IDEM have four sites co-located; IDEM and USGS have three co-located sites; and ORSANCO and USGS have two co-located sites.
Table 3. List of sampling sites sampled by multiple agencies/groups within Indiana.
Efficacy of Best Management Practices
Indiana ranks in the top ten of states in agricultural production; however, the production of crops and animals leads to non-point source runoff of nutrients and other agricultural compounds that affect water quality. There is a renaissance of late with the development of BMPs that work in the heavily tile drained areas of Indiana to keep more of the nutrients and sediment on the land and out of streams and groundwater. A primary research focus has become the ability to track improvements in water quality associated with these various BMPs, especially on an edge-of-field (EOF) approach. These studies are of importance to many of our agencies and are critical to understanding potential solutions to improve water quality in Indiana and downstream.
There are a total of ten EOF sampling sites ongoing in Indiana from 2016 (fig. 16 and table 4). Some use a paired watershed approach to highlight differences between land use and BMPs within the watersheds like Manchester University (map IDs 5,6) and Purdue University (map IDs 1-3) sites. An effort is made to have one watershed incorporate key BMPs. Some studies monitor important transport pathways including tile drains, overland flow, and streamflow to document which pathways are important for each form of nutrient or contaminant. The amount of water that passes through each pathway is measured so that loads can be calculated. For these studies BMPs, are changed part way through the study so that changes can be documented. The two Notre Dame sites (map ID 9,10), one USGS site (map ID 8), and the multiagency site (map ID 7) are examples of this second type of study.
Table 4. Site location information for the 10 Edge of Field sampling sites in Indiana.
Figure 16. Site location of Edge of Field studies in Indiana
Potential sites with existing USGS stream gages
If additional sampling sites are needed within Indiana, one potential way to keep costs down is to leverage existing USGS stream gages. Some of these stream gages are only stage (water level) and another cost effective change may be to upgrade to a full discharge stream gage. This map identifies the current 232 USGS stream gages in Indiana and on the Ohio River. Specific information on each gage is located in Appendix 7. A new assessment by the InWMC is underway to analyze the optimization of the stream gages in Indiana.
Figure 17. Location of existing USGS stream gages in Indiana.
1) West Fork White River.
– The West Fork White River includes the cities of Indianapolis, Muncie, and Anderson but land use is dominated by row crop agriculture. There are a total of 102 sampling sites within this Major River Basin: 40 sites sampled by MCPHD, 28 sites sampled by IDEM, 24 sites sampled by Citizens Energy Group in Indianapolis, five sites sampled by Muncie Bureau of Water Quality, three sites by the USGS, and two sites by IUPUI-CEES within this Basin (fig. 3 and 3a). The IDEM site (WWL030-0003) is co-located with the USGS gage at White River near Edwardsport (03360500) and integrates all the West Fork White River above the confluence with the East Fork White River. The White River at Hazelton (03374100) site integrates both the West Fork and East Fork White River and is being sampled by IDEM as part of the FSN program and the USGS as part of the NAWQA/NASQAN programs. The impact of the City of Indianapolis on the White River is monitored by IDEM (WWU160-0004) and is co-located at the USGS gage at Centerton (033540000). Fall, Eagle, Crooked, and Mill Creeks and the Eel River are important tributaries in this Major River Basin.
Figure 3. Map of the sites in the West Fork White River.
Figure 3a. Map of the sites in Marion County in the West Fork White River.
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2) East Fork White River.
– This Major River Basin includes the City of Columbus but has less of an urban influence than the West Fork White River; it is dominated by row crop agriculture. There are a total of 23 sites within this Major River Basin: 19 sampled by IDEM; three by the Citizens Energy Group, and one USGS NAWQA site (fig. 4). Four of the sites are located at a USGS stream gage. There currently is not a site that is being sampled that would incorporate water quality conditions for this basin. The closest sampling site to the mouth is the IDEM site, East Fork White River at SR 57 (WEL170-0001), however there is not a gage close to this site. The East Fork White River at Shoals (03373500) is the closest gage to the mouth currently. To integrate all the East Fork White River above the confluence with the West Fork White River, a gage closer to the mouth or potentially sampling at Shoals would allow loads to be calculated for the East Fork White River. It was sampled by USGS NAWQA between 1993 and 1995. Sugar Creek and Muscatatuck River are important tributaries in this Major River Basin. The East Fork White River is formed at the confluence of the Driftwood and Flatrock Rivers and other important tributaries are Sugar Creek and the Muscatatuck and Big Blue Rivers.
Figure 4. Map of the sites in the East Fork White River.
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3) Upper Wabash River.
– There are a total of 38 sites sampled within this Major River Basin: 35 sites sampled by IDEM, two by Manchester University, and one by Notre Dame University within this Basin (fig. 5). Of the 38 sites, 16 are co-located at USGS stream gages. Wildcat Creek, and the Mississinewa, Eel, and Tippecanoe Rivers are three of the larger tributaries in this Major River Basin. There are no gaged sites that IDEM samples at the mouth of this Major River Basin, but the Wabash River at Lafayette (03335500), which is located in the Middle Wabash River Basin, is the site that integrates all the Wabash River in the Upper Wabash watershed.
Figure 5. Map of the sites in the Upper Wabash River Basin.
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4) Middle Fork Wabash River.
– There are a total of 16 sites within this Major River Basin: 13 sites sampled by IDEM and three by Purdue University (fig. 6). The IDEM site, map ID 97 (WLV200-0001), located at the USGS gage Wabash River at Terre Haute (03341500) is the site that integrates all the Wabash River in the Upper and Middle Wabash watersheds. Of the 17 sites, 11 are located at USGS gages. The Big Raccoon, Big Pine, and Sugar Creeks are important tributaries in this Major River Basin.
Figure 6. Map of the sites in the Middle Wabash River Basin.
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5) Lower Wabash River.
– There are a total of five sites sampled in this Major River Basin: IDEM samples four sites; and USGS NASQAN and ORSANCO both sample the same site within this Basin (fig. 7). The Wabash River at New Harmony (03378500) is the site that integrates all the Wabash River above the confluence with the Ohio River. Currently, IDEM does not sample a gaged site to document water quality in the Wabash River as it leaves the state, but the NASQAN/ORSANCO data can be used. NASQAN has sampled this site since 1972. All of the tributaries in this Major River Basin are small but include Busseron, Big, Sulfur, and Turtle creeks and the Black River.
Figure 7. Map of the sites in the Lower Wabash River Basin.
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6) Great Lakes Tributaries.
– There are a total of 80 sites within this Major River Basin: 31 sites drain into Lake Erie through the Maumee River. Of these 31 sites, 12 are sampled by IDEM, eight by ARS, and 11 by the St. Joseph River Basin Initiative; 17 drain into Lake Michigan and all 17 are sampled by IDEM (fig. 8a-c). Thirty-two drain into the St. Joseph River, with 6 sampled by IDEM and 26 by the City of Elkhart. Most (24) of the IDEM sites that drain into Lake Michigan are located at drinking water intakes. There are three IDEM sites located at USGS streamflow gages in the Maumee and another four sites within ten percent of the drainage areas, but none in the St. Joseph. Important tributaries in the Lake Michigan Basin include the Grand Calumet and Little Calumet Rivers, and the Trail and Salt Creeks; in the St. Joseph Basin, important tributaries include, St. Joseph, Elkhart, Little Elkhart and Pigeon rivers and Pigeon Creek; and in the Maumee River Basin, important tributaries include Cedar Creek and the St. Joseph and St. Mary’s rivers.
Figure 8. Map of the sites in the Tributaries to the Great Lakes which includes
(a) Lake Michigan, (b) St. Joseph, and (c) Maumee Watersheds.
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7) Ohio River and Tributaries.
– There are a total of seventeen sites sampled in this Major River Basin that drain into or are on the Ohio River (fig. 9). IDEM samples eight sites, most of them tributaries to the Ohio River. The largest of these include the East Whitewater River at Abington (03275600). ORSANCO samples six sites and the USGS three sites on the Ohio River; one of those sites, Ohio River at Cannelton, is sampled by ORSANCO and the USGS NASQAN program. Indian and Laughery Creeks, and the Blue and Little Blue Rivers are the larger tributaries in this Major River Basin. One important contributing watershed that currently is not being sampled is the Great Miami River, which flows along the border of Indiana and Ohio. Additionally, to ascertain water quality in the Ohio River before it enters Indiana, a site downstream of Cincinnati and the Great Miami Rivers would be helpful.
Figure 9. Map of the sites in the Ohio River Tributaries Basin.
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8) Patoka River.
– There are two sites sampled by IDEM that are located within the Patoka watershed (fig. 10). The Patoka River at Winslow (03376300) is an IDEM site that is located near a USGS gage (7.9 percent difference). A primary water feature in this MRB is Patoka Lake which is an important drinking water reservoir. The Patoka River flows directly into the Wabash River on the western border between Indiana and Illinois.
Figure 10. Map of the sites in the Patoka River Basin.
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9) Kankakee River.
– There are a total of 11 sites sampled in this Major River Basin: seven by IDEM, three by the USGS, and one by Notre Dame (fig. 11). The Kankakee River flows into Illinois and the IDEM site, UMK110-0002, is located at the USGS stream gage Kankakee River at Shelby (05518000). The Yellow River and Iroquois Rivers are the important tributaries in the Major River Basin. The USGS has super gages (continuous multi-parameter sensors) at three sites, Kankakee River at Davis and three sediment gages in the Yellow River. The USGS has Nutrient Super gages at three Kankakee River sites, at Davis (05515500), at Dunn’s Bridge (05517500), and at Shelby (05518000). Additionally, there are three sediment Super gages on the Yellow River.
Figure 11. Map of the sites in the Kankakee River Basin.
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9) Whitewater River Basin.
– There are a total of five sites sampled by IDEM in this Major River Basin (fig. 12). Near the Indiana-Ohio state line, the Whitewater River flows south into the Great Miami River, which flows into the Ohio River. There is one co-located sampling site with a USGS gage, the East Whitewater River at Abington (03275600). The Nolands Fork and Greens Fork and Whitewater and East Fork Whitewater Rivers are the main tributaries in this Major River Basin.
Figure 12. Map of the sites in the Whitewater River Basin.
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