Grant-Platte Basinwide Issues

• Water Quality Problems
• Hydrology
• Streamflow Trends and Gauge Stations
• Infiltration
• Urban Runoff
• Characteristics of Stormwater
• Municipal Stormwater
• Industrial Stormwater
• Construction Erosion Controls
• Stormwater Management Planning

Mine Wastes

A major water quality problem, unique to this area of the state, is the effects of mining wastes on stream water quality. There are an estimated 300 zinc and lead mining sites in southwestern Wisconsin. Many of these sites have "roaster piles," a waste from ore processing, and other mining waste piles. Surface water quality and aquatic habitat in the streams near these piles is severely degraded, likely due to runoff from the piles.^(4,10,15,31) In addition, local groundwater quality problems have been linked with mine abandonment in the Shullsburg area.^(3,21)

The mines are no longer active, some having been abandoned for a long time, leaving no "responsible party" to help finance the cleanup.^(1,3,21) Adverse impacts on water quality and habitat have not been well documented, except in some extreme cases. We still do not know whether any long-term chronic water quality and habitat impacts exist from runoff and erosion of the mine waste piles, particularly the roaster piles.

Smallmouth Bass

Another resource problem in this basin has been the long-term decline of the smallmouth bass fishery, a problem the DNR has been investigating for a number of years. No one cause has been identified though there are numerous theories, among them: more intensive cash cropping resulting in increased use of pesticides, herbicides and fertilizers; more feeder cattle and hogs in the watershed increasing nutrient loading to streams; increased amounts of sediment in stream bottoms using up available dissolved oxygen during storm flows; runoff from farm fields, pastures, and barnyards increasing levels of pollutants in surface waters; and the effects of long-term exposure to toxics from roaster piles. Two probable primary factors for the scarcity of adult smallmouth bass are the impacts of regular fish kills during high-flow (storm) events and the overharvest of adult bass.⁽¹¹⁾

The use of macroinvertebrate monitoring, such as the Hilsenhoff Biotic Index, chemical monitoring, and habitat quality rating do not appear to be giving us a clear picture of why the sport fishery in southwestern Wisconsin is declining. A more intensive and continuous, rather than occasional and isolated, monitoring is needed. Embarking on such a monitoring effort requires a reordering of DNR regional and central office priorities, workload planning, and resources by bureaus of fisheries and habitat and watershed management and research.

Mississippi River

The Mississippi River, while technically not a part of this basin, is a water resource of international significance to which all the streams in the Grant-Platte basin are tributary. From fishery, wildlife, recreational, aesthetic, and economic standpoints, the Mississippi is important, and maintaining and enhancing its water quality is of environmental significance. A major water quality problem for the Pool 11 reach of the river, immediately adjacent Grant County, is the large volume of sediment and associated nutrients entering the pool from the Grant and Platte rivers. The annual sediment yields of the Grant, Platte and Galena rivers are among the highest in the state. The Grant River has annual sediment yields between 704-969 tons per square mile per year, the highest in the state.^(4,19,20) The Platte River has an estimated sediment yield of 182 tons per square mile per year.⁽⁴⁾ The Galena River has an estimated annual sediment yield of between 200 and 668 tons per square mile per year.^(19,20) These high yields from the Grant and the Platte rivers increases turbidity in the nearshore backwater areas of the Mississippi below the Grant River delta, decreases the depth to which sunlight reaches, prompting inconsistency in the abundance of aquatic plants; and causes a decline in high quality fish habitat due to sedimentation.(4)

While urban areas continue to grow--particularly in and around Platteville --the predominant land use in the basin remains agriculture. Agricultural lands include pasturing and cropland. This valuable land use comes, however, at an equally valuable cost: drained and altered wetlands; stream channelization; increased runoff carrying soil, nutrients and pesticides to surface waters; and groundwater contamination.

The primary sources of the basin's water quality problems are urban and rural polluted runoff. Problems associated with polluted runoff exacerbate one another so that factoring out the cause from the result is at times challenging. For example, excessive populations of rough fish, such as carp, thrive in turbid environments that might be the result of polluted runoff, but also contribute to that turbidity by scouring bottom sediment, resuspending nutrient-laden particles, and out-competing other fish that require higher water quality. Hydrologic modifications such as dams, stream straightening, and the ditching and draining of wetlands are significant contributors to lower water quality in the basin. Numerous low-head dams trap nutrient-rich sediment, effectively reducing the stream's depth, increasing water temperature, and precipitating algal problems. These types of water resource alterations have complex and reverberating effects on the system's balance, both from a water quality and a ecological balance perspective.

Water quality and quantity problems include:

• altered stream and groundwater hydrology;
• continued loss of aquatic and riparian habitat;
• sedimentation of streams, natural lakes and millponds;
• pesticide and nitrate contamination of groundwater; and
• increased quantity and reduced quality of stormwater runoff.

Sources of these problems, as mentioned above, are complex and interactive. Primary sources include changes in land use patterns, from low density rural to medium and high density suburban, and the subsequent increase in impervious surface area and alteration of regional hydrology. Also of concern are: streambank and cropland erosion; the continued presence of nitrate and pesticides in groundwater; and the continued loss of wetlands and subsequent simplification of fish and aquatic wildlife habitat throughout the basin.

A stream hydrograph is useful to biologists because it shows changes in stream flow over time. Dry weather stream base flow includes flow generated from groundwater discharged to the stream, which may be augmented by discharges from wastewater treatment plants or impoundments. The level of base flow for some streams is zero because flow only occurs during precipitation. Other streams have year-round base flow from groundwater discharge from seeps or springs. Peak flows are levels of stream flow recorded during storms when surface runoff contributes to the existing stream flow.

Land use that promotes over-land runoff rather than infiltration of precipitation has been shown to greatly affect hydrographs. A sudden increase in flow may be associated with flash flooding on some streams. The energy of this peak flow is dissipated by thrashing action against streambanks, which may result in streambank erosion, especially along trampled and/or poorly vegetated banks. In-stream habitat is also disturbed by high peak flows, which often carry sediment that eventually settles to cover "clean" substrate needed by fish and aquatic insects.

The topography of the basin affects the hydrography of its streams; moderate and high gradient streams are more easily drained than the low gradient streams of the glaciated portions of the state. Land use is a major factor in both of these settings. Enhanced overland runoff from rapid increases in impermeable land cover affects the stability of stream channels. Rapid onset of storms coupled with a flashy hydrograph can result in severe damage to a stream's riparian and in-stream habitat. An unstable stream channel will continually erode its banks until it reaches equilibrium. By improving infiltration throughout the watershed, the stream achieves a more gradual increase in flow coupled with lower peak flows during storms results in less overall stress to the stream channel and aquatic habitat.

Wisconsin has a network of stream flow gauging stations maintained by staff from the U. S. Geological Survey (USGS). Trend analysis of stream flows is not possible without continued funding to keep gauging stations functional. Documentation of stream flows is critical for assessing trends that may link decreased peak flow and increased base flow with improved water quality and in-stream habitat. Stream gauge station data is also necessary for calculating nutrient and other pollutant loading rates in streams with accompanying water quality data. The result of no or inaccurate data on stream flow can result in the following problems:

• Over or under design of flood peaks and bridges;
• Floodplain areas over- or underestimated;
• Under- or overestimation of low flows and over- or under-design of sewage treatment plants;
• Reduced accuracy of sediment load and flushing rate estimates.

WDNR should continue its financial support of the remaining gauging stations throughout the basin.

In 1992, James Knox and Douglas Faulkner of the University of Wisconsin-Madison studied the Lower Buffalo River in Wisconsin's driftless region to determine the source and reason for sedimentation at the mouth of the Buffalo River. Some of the study findings can be applied to streams statewide. The study findings included the following:

If widespread conservation practices that reduced upland erosion were implemented, sediment delivery to the mouth of the river may be reduced.

The reduction of upland sources of erosion without a complementary reduction in stormwater quantity to the river and its tributary streams may actually increase mobilization of existing sediment in the channels. Since stormwater would reach streams without an upland sediment load, the water would have a greater ability to mobilize sediment stored in stream channels.

Managing the rate of runoff and upland erosion would benefit the river and its tributaries. By allowing stormwater to recharge groundwater instead of running off into streams, two goals are accomplished: 1) the baseflow of tributaries to the river is increased from the groundwater recharge, and 2) damaging peak flows are reduced. Increasing tributary baseflows via infiltration lowers the stream temperature and increases stream volume during low flow periods; both of these actions enhance cold water species survival. Reducing the volume of peak flows reduces the magnitude and number of damaging flows that destroy fishery habitat and incise stream channels that move sediment downstream.

These management implications are applicable to the Grant Platte Basin's driftless topography.

Urban polluted runoff is problematic in urbanized areas of the basin, particularly Platteville. Polluted urban runoff takes two general forms: stormwater running off impervious surfaces such as rooftops, parking lots and streets, carrying sediments, nutrients, and other pollutants; and sediment-laden water flowing from development sites into streams and lakes.

Rainfall and snowmelt runoff is a major problem for surface water quality in many developed areas. Runoff from surfaces such as parking lots, streets, rooftops, and material storage yards as well as from lawns, is also a major source of pollutants reaching surface water and groundwater. In urban and suburban areas, a large percentage of land in developed areas is covered by impervious surfaces such as buildings and pavement, which collect and channel pollutant-laden stormwater. Principal water quality problems for the basin's urban streams are the result of the following factors:

• stream channel modifications, including straightening and lining with concrete
• high loading of pollutants including sediment, nutrients, bacteria, heavy metals and other toxic materials
• hydrologic disturbances, including flashy high flows and loss of base flow
• streambank erosion due to flashy high flows

Studies conducted in Madison, Milwaukee, and Eau Claire documented levels of metals, suspended solids and nutrients in stormwater effluent that exceed some in-stream water quality standards for stormwater runoff effluent. Stormwater runoff is a definitive source of pollutants that can be a significant cause of surface water quality degradation.

USGS conducted stormwater monitoring in seven drainage basins in the city of Madison from April, 1993, through November, 1994 (USGS). Seven different urban land uses were analyzed for inorganic and organic constituents. The data illustrate the flushing action of spring rains into waterways from urban areas, particularly industrial, high-density residential, highway, and shopping center (parking lots) land uses. Generally, the highest level and most frequent occurrences of total zinc were in industrial, light industrial, highway and shopping center (parking lot) land uses. The few instances in which semi-volatile organics occurred at levels higher than the limits of detection took place in industrial, high-density residential, highway, and shopping center land uses in March through May. The level of total phosphorus in stormwater peaked in the high-density residential area (2.38 mg/l) in November, 1993, while generally, the level of total nitrogen in stormwater was consistently higher in the high-density residential and university stormwater samples.

Regulation of Stormwater

The management and regulation of stormwater is divided among federal, state, county and local governments, depending on the land's status of incorporation and size and the activities affecting stormwater on the land.

Under Phase I regulations at the federal level, the U.S. Environmental Protection Agency (EPA) requires municipalities with populations of 100,000 or more to obtain coverage under a municipal stormwater discharge permit to control the discharge of pollutants. Phase II federal stormwater regulations, which are currently under development, will require municipal stormwater discharge permits for certain municipalities with populations of less than 100,000. In Wisconsin, EPA has delegated the authority to administer comparable stormwater regulations to WDNR. Under Chapter NR 216, Wis. Admin. Code, the following municipalities are required to obtain coverage under a municipal stormwater discharge: Madison; Milwaukee; municipalities in the Great Lakes Areas of Concern (Green Bay, Allouez, Ashwaubenon, DePere, Marinette, Sheboygan, and Superior); municipalities in a priority watershed that have a population of 50,000 or more (Eau Claire, Racine, West Allis, and Waukesha) and other municipalities identified by WDNR that meet certain criteria for permitting in section NR216.02(04). Milwaukee and Madison, including the University of Wisconsin-Madison campus, have obtained municipal stormwater discharge permits from the WDNR (Bertolacini).

To address flooding and control water quantity, the Federal Emergency Management Authority (FEMA) requires municipalities to perform floodplain mapping and management plan development to receive federal flood insurance.

Regulation of stormwater at the local level is generally confined to developing plans that "detain" water at some predetermined level--before development occurs--during the plat review and permit approval process. This local regulatory action takes place through voluntary ordinance development and its effectiveness hinges on enforcement, which requires resources and expertise in a time of diminishing public funds. Further, while site specific management helps with localized flood impacts and erosion, working within a larger picture, through comprehensive planning, is a more effective water management strategy.

Under NR 216, discharges of stormwater from certain facilities require coverage under an industrial stormwater discharge permit. The owner or operator of the permitted industrial facility is required to develop and implement a site-specific stormwater pollution prevention plan. The plan must be designed to ensure that there are practices in place to reduce exposure of industrial materials to stormwater, such as good housekeeping, spill prevention and cleanup and structural and non-structural controls.

As land is developed and disturbed, sediment moving off-site can be significant unless proper erosion control measures are implemented. In the Lake Mendota priority watershed (which includes the Yahara River-Lake Mendota Watershed (LR09) and the Six Mile and Pheasant Branch Creeks Watershed (LR10)) construction sites account for only .5 percent of the total land use in the watershed, but contribute 24 percent of the total sediment and phosphorus loading to Lake Mendota from all land uses (WDNR 1997).

Regulation of construction site erosion falls under several different programs in the State of Wisconsin. Locally, municipalities are required to adopt and enforce the Uniform Dwelling Code (UDC) under a program administered by the Department of Commerce. The UDC contains provisions to control erosion during construction of one- and two-family dwellings. Implementation of the UDC erosion control provisions is only as effective as the local municipality's willingness and ability to enforce the provisions. Oversight of a municipality's effectiveness at administering the UDC is handled by the Department of Commerce.

Larger construction sites involving land-disturbing activities affecting five or more acres are regulated by WDNR's Chapter NR 216, or equivalent programs administered by the Department of Commerce or the Department of Transportation. NR 216 requires a landowner of a larger construction site to obtain coverage under a construction site stormwater discharge permit. The landowner is required to ensure that a site-specific erosion control plan and stormwater management plan are developed and implemented at the construction site. Typical sites regulated by WDNR include residential subdivision development, industrial and business park development, parks and golf courses, and private, local and county roads. Through state statute and interagency agreements, regulation of erosion control at larger commercial building sites is administered by the Department of Commerce, and state administered highway and transportation projects, regardless of size, are handled by the Department of Transportation through Chapter TRANS 401, Wis. Adm. Code (Bertolacini).

The jurisdictional overlap and division of regulatory responsibility between WDNR, Department of Commerce, Department of Transportation, and local governments regarding erosion control has grown complex. Two areas that currently fall between the 'cracks' of erosion control include: 1) erosion from construction sites that do not include a one- or two-family dwelling and disturb less than five acres, and that are not regulated by a voluntary municipal or county ordinance; and 2) erosion from non-Department of Transportation road and bridge construction that disturb less than five acres and that are not regulated by a voluntary municipal or county ordinance. Currently, there is no state-level mechanism to address the first category. The Department of Commerce has been given the authority by state statute to develop a uniform commercial building code for erosion control regardless of the size of the commercial development, but this code has not yet been promulgated. As for the second category, WDNR and the Department of Transportation have a joint Memorandum of Understanding that addresses water quality impacts during construction of Department of Transportation-administered projects, typically state and interstate highway construction. Under the agreement, these transportation projects administered by the Department of Transportation must have an erosion control plan that is implemented throughout the construction period. Many small-scale transportation projects funded with local money are not, however, required to implement erosion controls. Local ordinances passed by a county, city, village or town are currently the only tools to protect water resources under these circumstances.

Phase II stormwater regulations that are now being proposed by the EPA would, however, drop the acreage threshold down to one acre for a construction site requiring coverage under a stormwater discharge permit. Consequently, like other states with delegated authority from the EPA to administer the stormwater discharge program, Wisconsin will need to modify its regulator program to address these smaller construction sites if the mandate survives at the federal level (Bertolacini). Currently, Dane, Walworth and Waukesha Counties have construction site erosion control ordinances in place that go beyond the uniform dwelling code requirements, while Jefferson and Rock counties do not have countywide ordinances. In 1997, Jefferson County Zoning turned down a proposal to adopt such an ordinance. Rock County's Land Conservation Department hopes to develop and adopt a countywide erosion control ordinance in the next two to three years. Rock County has gone so far as to offer to enforce existing erosion control provisions for local building inspectors to ensure that the UDC provisions were enforced; the county received minimal to no response.

But even the effectiveness of existing erosion control provisions is not known. Observations by WDNR staff and a 1989 report completed for the Dane County Lakes and Watershed Commission (Seyfert) indicate that local control of erosion in Dane County has room for improvement. Observations in Dane County range from no erosion control measures at major development sites to inadequate or improperly installed management practices (i.e., silt fences apparently only serving to mark the limits of the projects). At other sites poor or nonexistent follow-up maintenance measures were implemented.

While some developers genuinely attempt to control erosion, others have not initiated effective controls. The need for heightened awareness about the consequences of, and laws relating to, erosion control is evident. A better understanding of problems associated with construction site erosion by developers and contractors, coupled with improved enforcement of existing ordinances by local government, should be a priority.

During the past few years, UW-Extension has held a series of workshops on construction site erosion control for developers and contractors. The workshop series outlines the major features of the Wisconsin Construction Site Best Management Practice Handbook (PUBL-WR-222 92 REV). Community ordinances should remain consistent with current administrative rules and the model ordinance provided in the handbook.

Section 281.33 of the Wisconsin Statutes (formerly Chapter 144.266 Wis. Statutes) gives municipalities the option of enacting local construction site erosion control and stormwater management plans. Even if ordinances are developed, they have to be enforced. Possible reasons for lack of enforcement include too few resources; inadequate staff, training or knowledge; and fragmented responsibility and authority for administration and enforcement.

The thorough nature of comprehensive stormwater planning implies long-range and geographically broad consideration of flows and water quality during and after development of major land parcels, such as highways, industrial parks and residential neighborhoods. With few exceptions, maintenance of pre-development hydraulics is most desirable. The large-scale nature of comprehensive planning allows the integration of resources to reach multiple regulatory and management goals, such as those of FEMA, NR 216, sewer service area planning, local water management regulations and even management for aquatic and terrestrial wildlife.

Further implementation of the municipal stormwater discharge permit program under NR216 and the final Phase II regulations promulgated by the EPA will require some municipalities that meet certain criteria to obtain municipal stomrwater discharge permits, and to develop comprehensive stormwater management programs.

For more information about stormwater management, see the Center for Watershed Protection. (exit DNR)