Stillwater Creek Watershed Road Erosion Control Demo.llstration Water-~~ality Implicati.ons.

Transcription

1 Stillwater Creek Watershed Road Erosion Control Demo.llstration Water-~~ality Implicati.ons. EXHIBIT j 1 At the outset of this talk, I would like to acknowledge the sponsorship of this project and the outstanding cooperation that has led to its success. The project was sponsored by the US EPA and the Oklahoma Conservation Commission as part of the State Nonpoint Source Program under section 319 of the Clean Water Act. The Payne County Commissioners, and particularly Jim Arthur provided support and encouragement, and assistance with labor and materials for installation ofthe sites. Maxwell Supply oftulsa and North American Green donated the erosion control fabric and matting used in the project. Finally, the effort of Don Turton, in our Forestry Department, and Doug Wright and Mike Hinkston, of the LTAP program I... _", ~ ~,,_ :05-cv Oklahoma Ex. 4347

2 Sediment is the number one pollutant in Oklahoma. It clogs streams, destroys fish breeding areas and the habitat for aquatic macroinvertebrates that are so important to the food chain and the aquatic ecosystem. In addition, excess sediment causes flooding problems by blocking channels and culverts and is related to the turbididty problems of many Oklahoma lakes and streams.

3 The erosion problem of roads is critical to the sediment problem because virtually all roads are connected to drainways that move water directly into streams. Turton and others found in their study of the Lake Carl Blackwell watershed that 80% of all roads drained directly into creeks.

4 This is not unexpected because poor drainage of a road leads to rutting and erosion problems...:. 1"1_,,,

5 In the extreme case, water damage leads to a continuing problem. Some roads would be better closed than maintained.

6 The gully system along the edge of this road moves tons of sediment.

7 Stillwater Creek Watershed Erosion + l' This is the map of the Stillwater Creek Watershed. It shows the result of a computer modeling study of the erosion areas that deliver sediment to the creek. The dark red areas are the most erosive areas, most of which are crop fields, overgrazed pastures, and construction areas. The most erodible areas shown are eroding at a rate of about 20 mtons/ha or about 10 tons per acre. Small areas, ofcourse may erode at much ~ _,,1_4

8 Rural Roads paved and unpaved N A Road Surface -PlMld Gravel - Dllt and Gravel -Dirt '-...,-'::;:J o Miles The county has many roads, most of which are shown here. The modeling study divided them into paved, gravel, and dirt roads.

9 Erosion on unoaved rural roads N A Road Erosion kglmlyr o Miles Annual rates of erosion can exceed 100 kg/m of road, or about 200 tons per mile.

10 Erosion from Roads and Ditches predicted by computer model Road Type Paved Tons/mile Miles Tons Gravel ,310 Dirt TOTAL ,915 From measurement: 65,000 tons/yr The modeling study estimated the total contribution from roads to be almost 14,000 tons per year. Note that 3,000 tons are contributed by paved roads because eroding side slopes and ditch lines are a source of sediment. The current demonstration project suggests the modeling may have substantially underestimated this source......_,,--

11 Sediment Yield by Landuse Urban land 0% Roads & Ditches 11% Range & Pasture 12% The modeling study suggests that about 11 % of the sediment produced in the watershed comes from roads and ditches. 77% comes from cropland, and very little comes from urban areas.

12 Sediment Yield by Landuse (measured roads & ditches) Roads & Ditches 38% Range & Pasture 9% Urban land 0% When we insert the demonstration project numbers into this analysis, it suggests that as much as 38% of the sediment in the watershed may be coming from the rural roads. - "1_.._-

13 The Regulatory Scenario - and then the realistic situation Well what does all this mean for the future of regulations? We'll look at the possibilities, then the current outlook. M "1_..

14 Water samples tell tales The bottom line on all this erosion is that it shows up in our water. The cost of treating water is very dependent on its sediment load and turbidity, the aesthetics of our state depend on having good water resources. And that is what drives the effort to prevent erosion.

15 Water Quality Regulations Water Quality Standards Point and nonpoint sources Stormwater TMDLs Lets talk on how our system of water quality laws and regulations work. We'll disucss the Water Quality standards, point and nonpoint sources, stormwater, and TMDLs.

16 Water Quality Standards WQ Standards drive all the regulations. - Each water body has a designated beneficial use. - The WQ Standard is set to support that designated use. - The standard is violated, if the use cannot be supported Water Quality Standards are set by the Oklahoma Water Resources Board. The Water Quality standards are the driver for all the regulations and actions to prevent pollution in the watershed. The process works like this; each water body has a designated beneficial use. Then the standards are set to protect those uses. If the standard is not achieved, it is considered a violation that can initiate some kind of remedial action or regulation.

17 Designated Beneficial Uses affected by sediment Public Drinking Water Supply Fish and Wildlife Propagation Primary body contact recreation Secondary body contact recreation Aesthetics These are some of the beneficial uses that are designated for specific water bodies by the Oklahoma Water Resources Board. The first two are particularly important for sediment. Public drinking water supplies are sensitive to turbidity, and fish and wildlife propagation can be very sensitive to sediment.

18 Point Sources Discharge A point source is defined as any discharge that is carried through a pipe or man-made conveyance. The Clean Water Act divides pollutant sources into point sources and nonpoint sources. Point sources are ~ defined in the 1972 Clean Water Act as those sources that issue from a pipe or man-made conveyance. A man-made conveyance can be a discharge pipe or a channel. It can certainly be bar ditch, and it could even be an erosion gulley.

19 Nonpoint Source Discharge Everything else. Runoff from crop fields, streets, lawns, parking lots are considered nonpoint sources. The Act defines nonpoint source as "everything else." We normally think of fields, lawns, streets as nonpoint source. - "1_._-

20 What is the difference? Point sources can be permitted and regulated. Nonpoint sources are not regulated. - Any control must be achieved through voluntary action. - Hence we have agricultural cost sharing programs to induce farmers to control nonpoint source pollution. By designated a particular source to a point source it can be regulated with a permit. Nonpoint source, on the other hand, is completely voluntary, dependent on incentive programs and education.

21 Stormwater Stormwater is a means of regulating nonpoint sources. -If runoff is captured in a pipe, channel, or other man-made conveyance, it can be considered a point source. - The stormwater permit can be used to reg ulate it. - Urban areas now have stormwater permits. The definition of man-made conveyance has allowed EPA to move some nonpoint to point source. Stormwater is considered a point source. It is the runoff that is captured in a pipe or channel. Stormwater rules allow EPA to issue a permit for stormwater sources. The larger cities and communities in Oklahoma now have stormwater permits for their storm sewer systems. '".. I...

22 If a Water Body does not support its designated use A watershed study is performed. Set a Total Maximum Daily Load (TMDL) for each pollutant from each known source. Monitor to determine effectiveness. Adjust all permits as appropriate. When water quality standards are violated, there are several ways that regulations can kick in. First there is ~ a watershed study to determine what are the possible sources for the pollutant causing the problem. Then a total maximum daily load or TMDL is set for the discharge from each known source of the pollutant. In theory the state agency responsible can monitor the effectiveness of the strategy and adjust all the permits to ~

23 Sediment Yield by Landuse (measured amount for roads & ditches) Roads & Ditches 38% Range & Pasture 9% Urban land O J'o If this were to happen in a watershed with nonpoint sources, like Stillwater Creek watershed, the responsible agency would see only 3 major sources of sediment: cropland, roads and road ditches, and pasture and rangelands. Agricultural areas are exempt from stormwater, leaving rural roads as a likely target.... "1_4_-

24 Bar ditches are man-made conveyance Clearly, the road ditches associated with rural roads could qualify as manmade conveyances as defined in the Clean Water Act. And the stormwater permit could be invoked.

25 Fortunately there are tools to reduce this source, either in a regulatory or nonregulatory mode. We have the BMPs that are demonstrated in his project. /7

26 Will DEQ Regulate Bar Ditches? Not any time soon. But there are no guarantees in the long run. The fact, however, is that there is no immediate expectation that this will become regulatory in Oklahoma any time soon.