SUMMARY OF FINAL REPORT

Catastrophic Change on the Fawn River, Steuben Co.Indiana in May of 1998. Daniel E Willard, Jeffery R. White and Hendrick M. Haitjema. The Summary

A. About this report

This document reports the conditions on the Fawn River before during and after the release of fine-grained reservoir mud into the Fawn from the Orland Dam.

[Note 1] Throughout this document, the confined waters behind dams are called reservoirs: i.e. Greenfield Mills millpond is Greenfield Mills Reservoir, and Orland Millpond is Orland reservoir. The Orland Reservoir is all the flat water behind the Orland Dam extending about 1 mile.

The release occurred on 18 May 1998. Both IDNR personnel and local citizens observed the dam completely open, so that the reservoir water and sediment could flow out unimpeded on the 18th. The report will review descriptions by observers and experts on the Fawn before this event to determine the pre pollution condition of the river since 1969. These reporters will be natural resources professionals and lay observers. They agree that the Fawn in this stretch was a high quality, clear, gravel-bottomed stream.

We also review various studies by natural resource people and observations by experienced visitors that describe the condition of this stretch after the event of 18 May 1998. Several studies followed the effects of the release from 1998 to present. They conclude that the reservoir mud is still present and is not moving much. They conclude that the ecosystem has been permanently and adversely altered. This report follows the traditional source, transport, fate and effects" pattern often used in the description of pollution discharge events.

1.The source of the mud is the Orland Reservoir. Portions of mud were in the reservoir before 18 May 1998 and gone shortly after.

2. The flow created by fully opening the dam transported the mud from the reservoir to the Fawn River as far as the Green field Mills Pond.

3. The fate of the mud was deposition along the banks, in the oxbows and covered the bottom of over half of the stretch of the Fawn River. This covering of mud was not present before the release of 18 May 1998 and was present shortly after.

4. The effect of this wide spread deposition of reservoir mud was to reduce habitat for invertebrates and fishes, disrupted ecological systems, and turn the clean gravel river into a mud filled stream depriving citizens of recreational use and aesthetic pleasure. These effects are still present in April 2000 and will remain so indefinitely unless there is active clean up and restoration.

On May 18th 1998 personnel at IDNR's Orland Hatchery opened the dam on the Orland Reservoir and released an amount of water and anoxic fine-grained reservoir bottom sediment dredging out decades of mud that had built up behind the DNR dam. The dam stayed open for several hours and washed down an estimated volume of reservoir sediments, which when expanded resulted in deposition of approximately 100,000 cubic yards of mud into the reach of the Fawn River between the dam and Greenfield Mills Reservoir, that is about 6250 standard 16 cubic yard tri-axle dump truck loads. This mass of anoxic mud moved down the river by semi-solid flow, similar to cold oatmeal. IDNR admits to opening gates 10AM to 1:30 PM on 18 May 1998. IDNR denies that any sediment was released, or that any environmental damage occurred as a result.

[NOTE 2] Throughout this document we distinguish between normal, naturally occurring sediments found in the Fawn above the Orland Reservoir and the mud released from the Orland Dam on 18 May 1998. The released mud deposits have low plant fragment content throughout, are not laminated and lack any orientation and structure. They are low in organic content (... 60;0), have a homogeneous particle size distribution with a higher proportion of coarser grains relative to upstream sediments. Dr. Zaleha concludes that the material must be derived primarily from a single release of reservoir sediments under hyperconcentrated flow conditions. This mud will be identified as fine-grained sediments, or mud, or reservoir sediments, but it is all the same released material.

A sudden increase in flow, resulting from an approximately eight feet lowering of the water crest at the Orland dam, scoured out a channel in the reservoir sediments in Orland Reservoir [I & 2 in Figure I]. This channel in the sediments is evident on a series of photographs taken shortly after the release event.

The bottom sediments of the Orland Reservoir were resuspended in the rapidly flowing water and rushed into the Fawn River section downstream from the Orland dam [3 in Figure 1] and moved downstream as a "hyper-concentrated" mixture of water and sediments. Sediment concentrations between 400,000 to 800,000 mg//significantly increased the fluid density and viscosity , resuspending sand and gravel from the stream bottom and redepositing reservoir sediments. Further downstream when flow velocities dropped [4 & 5 in figure I]. That portion of the reservoir sediments that was not deposited along the downstream section of Fawn River entered the Greenfield Reservoir and, for the most part, settled there.

This influx of anoxic sediment, powered by the 8-10 foot head from the dam, spread a blanket of mud that varied from a few inches to several feet thick. In some areas the greatly increased flow did not allow the sediment to settle, but mixed the mud into the top few inches of gravel and sand. This infiltration of fine- grained material into the gravel inhibits the flow of oxygen to subsurface organisms. Rock surfaces and crevices, backwater and areas out of the main flow were also covered.

Down stream, as the energy dissipated, only occasional riffles were buried in thick mud deposits. The gravel in these areas became infiltrated with mud that reduced gas transport to organisms buried in the substrate. Oxbows and sloughs accumulated thick layers of reservoir mud which rapidly was deposited in the slower currents (6 & 7 in figure I.)

No normal open channel flow conditions at any stage (from base flow to flood stage) in the Fawn River could have led to the sediment structure and composition found downstream of the IDNR hatchery reservoirs. The only likely scenario leading to the formation of downstream mud deposits is catastrophic release of mud from the IDNR hatchery reservoirs during a single event. The material was deposited rapidly as the flow velocities decelerated after the initial high-flow condition on May 18, 1998. Using a fluvial transport model, Zaleha estimates the total suspended solids concentration to have been between 400,000 and 800,000 mg/1 during hyper-concentrated flow conditions.

Both first hand observations and subsequent research show that the accumulation of this deleterious material resulted from the release on 18 May 1998. Similarly, observations and research confirm the continued presence of large areas of reservoir bottom sediment, in places they had not been before 18 May 1998.

The Fawn River in Northern Indiana between the IDNR dam in Orland, and Greenfield Mills, Indiana meandered in a well-defined channel through wetlands and swales. The channel cross-section included a gravelly main flow area with sand and organic material at the edges in areas of lower flow. The water was usually well aerated and clear, with very low levels of suspended solid material. It contained shallow pools and gravelly runs. Trees provide climatic moderation over much of the reach. This clear water mix of habitats supported many aquatic insects and other animals that, in turn, fed Smallmouth Bass, Northern Pike, Walleyes and other cool water fishes.

Many qualified observers have noted the clear waters and wild quality of the Fawn River below the Orland Dam. They also describe the substrate as primarily clean gravel with some organic mud in the side channels. The Fawn River before 18 May 1998 was a lovely, clean gravel stretch of river. Many contend it was one of Indiana's better rivers. Lindsey et. al. in 19694:

[Note 4] Lindsey, A.A., D. V. Schmelz, and S.A. Nichols. 1969. Natura/Areas In Indiana And Their Preservation: The Report of the Natural Areas Survey. Indiana Natural Areas Survey, Department of Biological Sciences, Purdue University, Lafayette, IN. pg. 409

In December 1992, Pat Ralston, then Director IDNR, said in response to a request from Jones and Henry Engineering:

"The proposed project will take place at or near the Fawn River which constitutes a significant natural area... with relatively high natural values. The Natural Heritage Program's data indicates that several state listed plant species occur along the river, downstream of the state fish hatchery. Additional unrecorded state listed plant or animal species (or both) likely occur due to the high quality of the area's habitat."

[Note 5] Letter from Pat Ralston (Signed by Gary Doxtater, Deputy Director) December 171992 to Scott B. Sibley, Jones and Henry Engineers Inc. Toledo Ohio.

D. Results of the Release of 18 May 1998.

The sudden release of reservoir bottom sediment (mud) from the IDNR dam at Orland caused the clear water to become densely filled with this mud. The reservoir bottom sediment filled the gills of fishes and caused them to die. The same slug of mud settled on the bottom, covered logs and rocks. The dense material in the water clogged the gills of invertebrates and killed most of them. Many were either filter feeders or algae grazers. Those that survived the initial slug of sediment-filled water either choked to death or were unable to find food under the thick deposits of reservoir bottom sediment.

Some organisms did survive because they are in areas washed by sufficient current to carry away the burden of mud. Others are mobile enough to retreat into side areas out of the sediment flow, and return later. However much of the material remains covering the bottom, and submerged cover. This layer effectively removes over half of the benthic habitat in this stretch of the Fawn River .

Aesthetic and recreational uses are similarly, adversely affected. Wading or swimming is unpleasant and stirs up large clouds of mud. The bottom is uniformly discolored and covered with masses of slimy algae. Large reefs of deposited mud are evident throughout. This once esteemed stretch of river is aesthetically displeasing and ecologically crippled.

Recovery and Restoration of the Fawn River

Recovery of the system has been slow. The deposits of anoxic mud continue to inhibit the passage of oxygen into the gravel substrate where it is necessary for bottom-dwelling animals and plants. The reservoir bottom sediment also serves as a blanket depriving these organisms of light and food. Because there are few healthy plants in the water there are few herbivores and thus few carnivores. The food chain has been destroyed and has not been able to recover significantly because of the pervasiveness of the reservoir bottom sediment.

Restoration of the Fawn River between Greenfield and Orland will require removal of the reservoir bottom sediment throughout the system. Removal should include the cleaning of the sand and gravel bars that are embedded with anoxic fine sediment. Rocks and woody material in open flow areas should be cleaned without unnecessary disturbance of the surfaces. Invertebrate populations must be allowed and encouraged to recolonize through drift with the introduction, if necessary, of additional clean substrate. After these species have repopulated, the Fawn River may require artificial restocking to supplement natural immigration and reproduction of fishes.

The process will require care to avoid unnecessary destruction of bank and riparian vegetation. Necessary destruction will require a plan to reestablish the destroyed areas. The reconstructed river should be designed to resemble its pre-impact appearance, in so much as natural events will allow.

This restoration will require, a minimum of ten years of monitoring and adaptive management. Regular reports of the condition of the channel morphology, invertebrate and fish populations and stream bank condition should dictate management activities. The dam and other water flow controls in the system must be managed so as not to not to stress the restoration process.