Bogged Down on Mirror Pond

A river wants to be a river, not a pond. You can make a river behave like a pond for a while by putting a dam in front of it, but sooner or later – sooner if the pond is shallow – the area outside of the main channel will fill up with sediment and the river will go back to being a river again.

Therein lies the dilemma for the City of Bend, which for decades has been wrestling with what to do about Mirror Pond.

The pond, formed by a dam built a century ago, is often described as “the jewel of downtown Bend,” but that jewel has a tendency to tarnish. Silt keeps building up until the pond threatens to become a mud flat – a problem exacerbated by spring and summer irrigation flows, which wash soil away from riverbanks upstream.

The city has had to dredge Mirror Pond once before, in 1984. Back then the cost was only $312,000. Now the silt has gotten thick again and the city is thinking about another dredging project. But the cost of doing that, including disposing of the possibly contaminated silt, would now run into the millions.

The city can’t spare that kind of money. It decided it couldn’t even spare $500,000 for a study to figure out the best way to handle the sedimentation problem.

So instead it looks like the city is going to ask the voters – maybe as soon as November 2012 – to create a tax district that will pay for present and future dredging of Mirror Pond.

That’s a bad idea, and here’s why:

Committing to dredge Mirror Pond in perpetuity would put the city on a never-ending – and very expensive – treadmill. The need for dredging probably is going to get more frequent as more development occurs up-river from the pond. (It took 73 years before the pond needed dredging the first time, but only about 25 before it needed dredging again.) And you know it’s not going to get any cheaper.

The new tax district also would increase the overall tax burden on local residents and make them less likely to approve future levies for other, higher-priority needs like police or schools.

Advocates of dredging act as if the only alternative is allowing the pond to turn into a mud flat. But they’re offering a false choice.

In place of Mirror Pond, picture a sparkling river flowing through a broad, green meadow. Imagine people canoeing, kayaking, fishing, bird-watching, picnicking, or just sitting on the banks and watching the water go by. That isn’t so horrible, is it?

If you want a clearer idea of what it might be like, take a look at River Bend Park upstream from the Old Mill District, where the riverbank has been allowed to “go natural.” It’s become one of Bend’s most popular spots for locals and visitors alike.

It’s time for some out-of-the-box – or maybe that should be “out-of-the-mud” – thinking about Mirror Pond. Instead of trudging along on the endless dredging treadmill, the city should give the dredging idea THE BOOT. Permanently.

Source:  The Source Weekly ©2012

Condit Dam Removal Explained

In late October, 2011, the White Salmon River in Washington flowed again as the nearly 100-year-old Condit Dam was disabled with explosives. See this spectacular video of the dam’s lake draining, and find out how the end result is affecting habitat for salmon spawning. Further dam demolition is scheduled in 2012. The event was a significant milestone for river restoration and dam removal nationwide. This video is by Andy Maser.

Condit Dam Removal

On Wednesday October 26th, 2011, Condit Dam on the White Salmon River was dramatically breached with explosives. This was the first step in a year-long project to remove the 100 year-old dam and restore spawning habitat for threatened salmon.

This video is by Andy Maser.

Hemlock Dam removal one year later

Trout Creek flows freely after 100 years.
Trout Creek flows freely after 100 years.

The roar of rushing water makes conversation difficult as you cross the bridge over Trout Creek in Washington’s Gifford Pinchot National Forest. The creek – really more of a river – burbles over boulders and stones. It winds its way past banks scattered with tiny native saplings and shrubs. Birds skim the water and rest on tall grasses along the banks.

What isn’t immediately obvious is that one year ago, this entire scene was under water. The dramatic change in the area is due to a Bonneville Power Administration-funded U.S. Forest Service project that removed Hemlock Dam and reconstructed Trout Creek to a natural state. The $2.7 million project made an immediate difference for the fish: hours after the dam was removed and the stream was re-watered, an adult steelhead was seen making its way upstream.

Hemlock Dam was originally constructed in the 1930s. Over the years it generated hydropower and later provided irrigation water, but stopped serving any purpose in 1997. The 26-foot high concrete dam not only blocked fish on their migration up the creek, but also created a shallow reservoir, flooding the area with several feet of water that heated up in the sun to temperatures above what the fish could bear.

The U.S. Forest Service declared the dam the main limiting factor in recovering endangered wild steelhead in the area, so BPA, in coordination with the Northwest Power and Conservation Council, stepped forward in 2007 to help fund the removal of the dam and reconstruction of the creek. “BPA’s support was critical to the success of this project,” said the Forest Service’s Bengt Coffin. “Once they signed on, many other agencies stepped forward to lend their support as well.”

One year ago in July, removal of the dam began. Biologists carefully relocated all the fish from the creek before a massive pump drained the water and piped it around the dam site. Then, heavy equipment worked from dawn till dark to remove the concrete dam and chunks of a logging dam dating back to the turn of the century. Engineers dug out a sinuous channel and created an in-stream island that serves as a flood plain. Crews anchored the island with huge logs and snags salvaged from the old dam. They used natural materials like gravel and rocks, rather than the usual metal cables, to anchor the logs in place.

The creek bed was lined with rocks and stones specifically sorted by size to attract spawning steelhead. A wetland was created nearby to replace wetlands that had grown up around the reservoir. Thousands of native plants were planted to provide shade to the creek and stabilize its banks.

Since 2005, BPA has funded projects that have opened up more than 1,000 miles of habitat for fish by removing obsolete diversions, dams, mine tailings and other barriers. “BPA is committed to protecting and improving the environment for fish and wildlife in the Pacific Northwest,” says Bill Maslen of BPA’s Fish and Wildlife Division. “This project is a great example of the painstaking science behind our efforts to protect and enhance habitat for fish. In this case, dam removal made perfect sense.”

The Hemlock Dam Removal project was also supported by the U.S. Forest Service, Salmon Recovery Funding Board, the Yakama Nation, U.S. Fish and Wildlife Service, Ecotrust, Mid Columbia Fisheries Enhancement Group, NOAA Fisheries and American Rivers.


Rivers, Sediments and Dams

David Freyberg, Professor of Civil and Environmental Engineering at Stanford, discusses his involvement in the Woods Freshwater Initiative with his ongoing research on the increasingly common practice of dam removal in the United States, along with a detailed long-term case study on the Searsville Dam in Palo Alto highlighting many of the hydrological challenges involved in making an effective dam removal decision.

Stanford University

Woods Institute for the Environment

Stanford University Channel on YouTube


Returning steelhead steal the show

Success of the restoration project was shown just hours after completion by steelhead coursing down the new channel.

Many volunteers pitched in to safely remove steelhead and other fish species prior to dam removal and stream reconstruction.
Many volunteers pitched in to safely remove steelhead and other fish species prior to dam removal and stream reconstruction.

Only hours after water coursed down the new stream channel, the first returning steelhead signified the success of the Hemlock Dam Removal/Trout Creek Restoration project. Hemlock Dam was built in the 1930s for power generation by the Civilian Conservation Corps. It was later retrofitted to provide irrigation storage for the Wind River Nursery, which closed in 1997.

Removal of Hemlock Dam is a study in contrast with the removal of Marmot Dam on the Sandy River in Oregon. Marmot Dam was removed in part by use of explosives, and the sediments behind the dam were eroded away by the river once the dam was gone.

At Hemlock, the dam was torn apart piece-by-piece using heavy equipment. Sediments that had accumulated behind the dam in the past 70 years were largely removed by excavators and large dump trucks. A channel was built in the area that was once a reservoir. The constructed channel is the latest in “green” technology, being built of river rock and approximately 1,000 trees that were pushed over or cut as part of a forest thinning project elsewhere in the watershed.

Hemlock Dam in the 1930s.
Hemlock Dam in the 1930s.

The new channel is not the only “green” part of the project. Project contractor James Dean of Glenwood, Wash., recycled concrete from the dam for use in other projects. Dean also found a way to replace diesel pumps used to divert the creek on the site with electric pumps, further burnishing the green credentials of the project.

Prior to use of heavy equipment in the reservoir area, the Forest Service along with partner agencies and organizations conducted a three-day effort to remove fish from the project area and were able to capture and relocate nearly 3,000 fish to a safer area for the summer. Once the fish had been removed, the site was dewatered by flipping the switch on 4 large electric pumps, which pumped the entire flow of Trout Creek around the project site through a series of nearly half-mile-long, high density plastic pipes.

As the contractor was excavating sediments from the lower reservoir, a piece of Skamania County logging history was unearthed. The foundation of an old timber-framed splash dam was exhumed, and found to be in nearly mint condition, compliments of being buried by many feet of sediment and water for the past 70-plus years.

The splash dam was once used to temporarily impound water so that it could be released in large pulses to wash timbered logs downstream to the mill. Following initial revelation of the splash dam, it was carefully uncovered, surveyed, and measured by a team of archaeologists along with the Skamania County Youth Forest Success crew, and then removed to make way for the newly restored channel.

A web cam is located on the project site that allowed Web site visitors to view (and even take photos) of work on the project. Visitors to the Web site can actually take control of the Web cam from the comfort of their own chair and can pan across the site, zoom to points of interest and take photos of anything that is particularly interesting. The Web cam is a result of a partnership between the Forest Service and University of Washington’s Canopy Crane program, which is co-located near the project site.

The dam removal and habitat restoration project comes about as a result of funding contributions and support from a wide array of partner organizations and agencies, most notably Bonneville Power Administration, U.S. Fish and Wildlife Service, Salmon Recovery Funding Board, Ecotrust, American Rivers, NOAA Fisheries Restoration Center, Yakama Nation and Mid Columbia Fish Enhancement Group.

Visit the Gifford Pinchot National Forest Web site to access the Web cam: For additional project information please contact Bengt Coffin, Project Manager at (509) 395-3425.

Hemlock Dam Removal and Trout Creek Restoration

Background Information

Hemlock Dam was on the National Register of Historic Places. Before its removal, it was the only surviving concrete dam constructed by the CCC on the west coast. The fish ladder is one of the earliest fish ladders in the Pacific Northwest. The dam replaced an earlier timber splash dam located between 70 and 140 feet upstream. A picnic and camping area with small boat launch was first established upstream of the dam on the left bank in 1935. Hemlock Dam impounded a small, shallow lake, which was about 6.5 acres in size and the lake was used by an unknown number of local residents for recreation.

The reservoir behind Hemlock Dam filled with between 48,000 and 93,000 yd³ of sediment. There is a large range of uncertainty in the reservoir sedimentation volume because there is no pre-dam topographic survey of the reservoir bottom. The reservoir sediment is predominantly sand with a median grain size of 0.6 mm. Less than 10 percent of the sediment volume is silt and less than 10 percent is gravel and cobble. Sand deposition in the downstream portion of the reservoir has likely filled the reservoir’s sand storage capacity so that inflowing sand and finer-sized sediment tends to pass through the reservoir. However, the coarse delta in the upstream portion of the reservoir continues to grow at a slow rate. Gravel and cobble deposition was expected to completely fill the reservoir in 200 to 300 years.

Downstream from Hemlock Dam, Trout Creek enters a steep and narrow bedrock canyon where it flows into the Wind River 1.5 miles downstream from the dam. From this confluence, the Wind River continues down the steep and narrow bedrock canyon where the river mouth is in the backwater of Bonneville Reservoir, located on the Columbia River.

Hemlock dam no longer produced power or provided irrigation storage, but continued to affect steelhead by impeding upstream and downstream movement of the fish, increasing water temperatures in lower Trout Creek, and obstructing downstream movement of valuable stream sediments.

Trout Creek is located in the Wind River watershed in southwest Washington. The Wind River is a Tier I Key Watershed on the Gifford Pinchot National Forest, and as such is a top priority for aquatic habitat restoration. Trout Creek provides critical habitat for Lower Columbia River steelhead, a fish listed as Threatened under the Endangered Species Act. This project will improve conditions for the fish and restore natural riverine processes to lower Trout Creek. Trout Creek was once known for producing a disproportionately large share of the wild steelhead in the Wind River, and this project aims to help restore that mantle.

Restoring Trout Creek

Since the early 1990’s, the Forest Service along with partner agencies and organizations have focused restoration efforts on Trout Creek, in efforts to restore the historically exceptional steelhead habitat. Riparian, upland, and instream habitats in upper Trout Creek have been enhanced by projects intended to reduce fine sediment introduction to Trout Creek, to provide increased shade on the stream, to improve fish passage at road crossings, and to improve instream habitat by placement of woody debris complexes. Removal of Hemlock Dam and restoration of lower Trout Creek contributes to this whole-watershed approach to habitat restoration, and is the culmination of many years of planning.

Project Goal

The goal of the restoration project is to increase the viability and productivity of Lower Columbia River Steelhead in the Wind River.

To meet this goal, the restoration project has these objectives:

  • Improve passage for fish and other aquatic organisms
  • Reduce peak stream temperatures in lower Trout Creek.
  • Improve quality of channel bottom substrates throughout lower Trout Creek
  • Increase habitat complexity in lower Trout Creek

Project Elements

  • Remove Hemlock Dam along with associated buildings and structures
  • Excavate excess sediments from the reservoir area
  • Construct a channel in the area now occupied by the reservoir
  • Incorporate large woody debris in the channel and floodplain
  • Physically remove and/or treat invasive vegetation in the project area
  • Revegetate the area surrounding the new channel

Lower Columbia River Steelhead

The Lower Columbia River Steelhead was listed as a threatened species on March 19, 1998 by NOAA’s National Marine Fisheries Service. The Lower Columbia River Steelhead is considered a distinct population segment (DPS).

The DPS geographic area the Lower Columbia River Steelhead includes all naturally spawned steelhead populations below natural and manmade impassable barriers in streams and tributaries to the Columbia River between the Cowlitz and Wind rivers in Washington, and the Willamette and Hood rivers in Oregon. The Lower Columbia River Steelhead DPS also includes ten hatchery programs on rivers and streams within the same geographic area. History of the Site Hemlock Dam was built by the Civilian Conservation Corps (CCC) in 1937 to provide irrigation and power to the adjacent Wind River Nursery. With the closure of the nursery in the 1990s, the irrigation and power generation function was no longer needed. In the seventy years since the dam has been in place, sediment behind the dam has increased and water temperatures have risen to lethal levels for fish.


In December of 2005 Mt. Adams District Ranger Nancy Ryke signed a Record of Decision (ROD) today calling for removal of 70-year-old Hemlock Dam northwest of Carson, Wash.
Ryke chose Alternative C of the final Environmental Impact Statement (FEIS) for the Hemlock Dam Fish Passage and Aquatic Habitat Restoration Project. It called for dredging years worth of sediment that has built up behind the CCC structure before the dam itself was removed.

“Removing the dam and its sediment is the best way to fulfill our obligation to enhance fish passage for threatened steelhead,” Ryke said. “We have put a lot of effort into this study, and I believe it’s the right course of action to achieve our objectives for steelhead recovery.”

Hemlock Dam is located on Trout Creek, a tributary to the Wind River, approximately 10 miles northwest of Carson, Wash. The dam has been identified as an impediment to the migration and survival of Lower Columbia River steelhead, a fish that is listed as threatened under the Endangered Species Act.

Copies of the FEIS and ROD are available online.


The restoration project involved key milestones including:

  • Facility Removal – Remove small buildings such as the pumphouse located just southeast of the dam.
  • Creek Diversion – Diverting Trout Creek upstream through 2 or 3 large pipes and returned below the existing dam.
  • Hemlock Dam Removal – Dismantling he 22-foot high Hemlock Dam.
  • Invasive Weeds – Removal of a growing population of invasive weeds.
  • Stream Channel – A large amount of accumulated sediment was removed upstream of the dam. The natural channel for Trout Creek was restored.
  • Riparian Restoration – Once the natural channel is established, native plants and trees that were planted will provide shade and complexity to the area.
  • Recreation Site – The Forest Service will work with interested publics to identify recreational development at the site.


The restoration of Trout Creek and the benefits to the federally listed Lower Columbia River Steelhead would not be possible without the financial support of the following partners:

  • Bonneville Power Administration
  • Salmon Recovery Funding Board
  • Yakama Nation
  • American Rivers
  • Ecotrust
  • U.S. Fish and Wildlife Service
  • NOAA Fisheries
  • Mid-Columbia Fisheries Enhancement Group


Hemlock Dam Removal (PDF)

Marmot Dam Removed

In 1906 the Marmot Dam was built on the Sandy River near Mount Hood. Nearly a century later, PGE decides to remove it. But will the tons of sediment built up behind the dam harm the river downstream once the structure is removed? The National Center For Earth Dynamics at the University of Minnesota and other experts weigh in. See what happens as the Marmot Dam is removed.

First Broadcast: 2008
Producer: Vince Patton
Videographers: Todd Sonflieth, Nick Fisher
Editor: Nick Fisher
Audio: William Ward
Field Producer: Milt Ritter
Video courtesy of: Portland General Electric
Photos Courtesy of : US Geological Survey

Appeared in episode:  Marmot Dam Removed, Fire Tower, Ice Worms

Video Extra: Time Lapse Video: Coffer Dam Face

Source: OPB: Oregon Field Guide

Regulatory Guidance Letter No. 05-04

SUBJECT: Guidance on the Discharge of Sediments From or Through a Dam and the Breaching of Dams, for Purposes of Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act of 1899

1. Purpose and applicability

a. Purpose. The purpose of this document is to provide guidance to Corps Districts Engineers regarding which releases of sediments from or through dams require Department of the Army (DA) permits. Nothing in this guidance is intended to require a DA permit for routine high water flow dam operations that allow sediment-laden waters to flow from or through a dam; however deviations from normal dam operations resulting in the discharge of bottom sediment may require a DA permit.

b. Applicability. For purposes of Section 404 of the Clean Water Act (CWA) and Section 10 of the Rivers and Harbors Act of 1899 (RHA), this guidance applies to the releases of water and water- carried sediment that may result in the transportation, reduction, or elimination of bottom sediment accumulations from or through dams. Dams, as used in this guidance include, but are not limited to, barriers that create impoundments of water. Depending on factors discussed below with regard to exempted maintenance activities and de minimis impacts, these releases may or may not result in a regulated discharge of dredged material. Regulated discharges may occur in association with the breaching of dams but do not include breaching that results solely from acts of nature.

2. Background

a. Sediment transportation in a stream or river is a natural process that helps to maintain the geomorphology of a stream channel. However, when a dam is constructed on a stream, it tends to interrupt the natural transportation of sediments, which build up behind the dam. This can result in sediment-starved sections of a stream downstream of a dam, leading the stream to down cut or erode away its bed and banks. Sediment accumulation behind a dam also reduces the capacity of a reservoir to store water, and can interfere with operation of the dam.

b. Sediment may be removed from a reservoir basin using many different mechanical methods, including draglines, bulldozers, or other equipment. Sediment that has been removed by such mechanical means can then be transported to a site above the Ordinary High Water Mark (OHWM) of the reservoir and stabilized. Under certain specific circumstances and when authorized by a DA permit, such sediments can be re-introduced into (i.e., discharged into) the river below the dam.

c. If a dam operator modifies or deviates from normal operation of the dam in such a manner that bottom sediment accumulated behind a dam could be removed and transported downstream through the dam, either deliberately or accidentally, that activity may require a DA permit pursuant to Section 404 and/or Section 10, as explained further below. (Note: CWA Section 404(f) exemptions from the permit requirement may apply in situations where only CWA jurisdictional waters are involved). DA permits may require special conditions minimizing the potential adverse effects on the downstream aquatic environment of releases of sediments subject to DA regulation. For example, the discharge of sediments through a dam that allows those sediments to be washed downstream may, in some circumstances, provide beneficial sediment material to sediment-starved sections of a stream below the dam. However, sediments proposed for discharge through a dam may also be of the wrong type to benefit a stream (e.g., mud or fines as opposed to gravel). Such fine sediments can seriously degrade important aquatic habitat, as when silt or mud sluiced through a dam covers up spawning areas for fish at critical times in their lifecycles, or fills in niches for invertebrates in large cobble bottom systems. Sediments proposed to be discharged through a dam may also be out of sync with the natural pre-dam sediment flow regime of that stream, which historically moved much of the sediment in the stream immediately before, during and after high flows such as spring run-off. The uncontrolled discharge of sediments may kill thousands of fish due to the impairment of their ability to process oxygen. The natural, pre-dam flow regime originally produced the stream channel geomorphology, so much of the stream biota is adapted to that historic pre-dam flow regime and sediment load and size.

d. One recent court case specifically addressed the need for a DA permit for sediment sluicing activities. The case of Greenfield Mills v. Macklin originated when employees of the Indiana Department of Natural Resources sluiced large quantities of accumulated sediments through a dam into the river below the dam without having first obtained a DA permit under CWA Section 404. Before deciding the case, the U.S. Court of Appeals for the Seventh Circuit asked the U.S. Department of Justice (DOJ) to provide the consensus views of the Federal Government (i.e., of the U.S. EPA and the Corps of Engineers) regarding whether the sluicing of sediments through the dam under consideration in that case required a DA permit. The DOJ provided an Amicus Curiae brief to the Circuit Court as requested, and the Court in large measure based its decision on the legal positions that the Federal Government presented in that brief. The Amicus brief may be found at Both the Federal Government’s brief and the Court of Appeals decision clearly hold that the sluicing of sediments through the dam constituted hydraulic dredging and the discharge of dredged material from a point source (i.e., the dam), which occurred when the dam’s lower gates were opened and the bottom sediments were sluiced downstream. The discharge of dredged material under those circumstances was an activity that required a DA permit pursuant to Section 404 of the CWA, unless that discharge was exempt from the Section 404 permit requirement under CWA Subsection 404(f).

e. These types of discharges of sediments may also be potentially regulated as fill material. Final revisions to the CWA Section 404 Regulatory Program definitions of “fill material” and “discharge of fill material” were issued in the final rule of May 9, 2002. That final rule defined “fill material” in both the Corps and EPA regulations as material placed in waters of the U.S. where the material has the effect of either replacing any portion of a water of the U.S. with dry land or changing the bottom elevation of any portion of a water. Based on this “effect” determination, DA permits are generally required for the discharge of sediments from dams when such activities would have the effect of raising the bottom elevation of the downstream waters to a discernible, substantial degree. For example, when accumulated sediments are discharged through a dam by opening the lower gate(s) of the dam to move substantial

quantities of sediments, that discharge could reasonably be expected to raise the bottom elevation of the downstream waters, thereby constituting the discharge of fill material into that water body.

3. Types of Discharges

a. Discharges that are not regulated. Even when using the upper or middle gates of a dam to release water, some sediment is always included in suspension in the water releases. However, the release of sediments that are incidental to normal dam operations (i.e., the release of water through the dam to provide irrigation water or drinking water, to provide water for downstream depth for navigation, to restore reservoir capacity to store spring run-off or potential flood waters from storm events, etc.) are considered de minimis discharges of dredged material. For purposes of the Corps regulatory program, these de minimis discharges of suspended bottom sediments generally do not trigger the need for a DA permit so long as they are consistent with those sediment loads entering the reservoir from the upstream waters.

b. Applicability of 404(f) Exemptions. The discharge of large quantities of sediment through a dam will rarely (if ever) qualify as exempt from CWA regulation under CWA Subsection 404(f), for the reasons explained at length in the Greenfield Mills decision. (Note: There are no statutory exemptions that apply to such large-quantity discharges of sediments for purposes of the Section 10 permit requirements in Section 10 waters.) In summary, CWA Subsection 404(f)(1) exempts from CWA regulation “ . . .the discharge of dredged or fill material . . . for the purpose of maintenance, including emergency reconstruction of recently damaged parts, of currently serviceable structures, such as . . .dams . . . .” unless the discharge is “recaptured” under Subsection 404(f)(2) (emphasis added). Consequently, the discharge of sediments through a dam cannot be exempted from CWA regulation under Subsection 404(f)(1) unless those sediments must be released for the purpose of dam maintenance, and not for any other purpose such as maintenance of the reservoir pool. Moreover, as a general rule, the Subsection 404(f) exemptions are construed narrowly to avoid their misapplication as well as the resultant adverse environmental impacts, either site-specific or cumulative. As the Greenfield Mills decision explains, for the discharge of sediments to qualify for the Subsection 404(f) exemption for dam maintenance, such discharges of sediments through a dam would have to be both necessary to allow essential dam maintenance to occur, and would have to be proportional to the dam maintenance activities that necessitate the release of sediments. Given the fact that sediments that have accumulated behind a dam can usually be removed practicably and more precisely by mechanical means, with little or no serious adverse downstream environmental effects, it is rarely necessary to sluice substantial quantities of sediments through a dam in order to accomplish essential dam maintenance. The Subsection 404(f) exemption will rarely, if ever, be applicable to the discharge of large quantities of sediments through a dam.

c. Discharges requiring DA permits. As stated above, sediment frequently builds up behind a dam. At times, rather than remove such accumulated sediments by mechanical means, a dam operator may open the bottom gates of the dam, allowing water to flow at high velocity over the sediment and flush it downstream. This can result in significant amounts of accumulated bottom sediment from upstream of the structure being allowed to move downstream with a composition or at a time period that is inconsistent with the viability and health of the downstream system. Discharging large amounts of sediments through a dam may not be planned, but may result when the sediment is mobilized due to

increased water releases through a dam when the reservoir pool is low. Similarly, when a dam is breached, it generally causes the sediment behind the dam to be eroded rapidly, usually in a discrete (single) event or a series of discrete events, which move the sediments downstream.

Regardless of whether the dam operators had the intent to discharge sediment through the dam and out of the water impoundment, the opening of the lower gates of the dam has the effect of allowing substantial quantities of sediment material to travel downstream, thereby constituting the discharge of dredged material (and possibly fill material, as well) from a point source, thereby requiring a DA permit.

4. Analysis and Policy

a.As a general rule, the discharge of substantial quantities of accumulated bottom sediment from or through a dam into downstream waters constitutes a discharge of dredged material (and possibly of fill material) that requires a CWA Section 404 permit. The discharge of substantial quantities of sediment through a dam will rarely, if ever, qualify as exempt under 404(f). Such activities may also require a DA Section 10 permit if they occur in “navigable waters of the United States”, and no statutory exemptions apply to Section 10 for such discharges into navigable waters. This policy includes the human-induced breaching of dams when sediment has accumulated in the reservoir basin and is released downstream.

b. Activities that are not usually considered regulated discharges of dredged material and do not require DA permits include actions such as the operation of continuously sluicing structures that mimic the natural increase and decrease of sediment in a stream (i.e., the amount of sediment discharging from or through a structure is comparable to the amount of material entering the reservoir from upstream); breaching or removal of a dam that results in the movement of only de minimis amounts of material or that results solely from an act of nature; releases during times of high water or flood stages for purposes of passing flood waters through the dam; and the lowering of lake or pond levels that results in the release of only de minimis amounts of sediment.

It should be noted that there is often high variability in the amount of sediment and water carried by rivers and streams over an annual cycle. Such high flows may occur as a result of storm runoff or seasonal runoff of melting snow pack. Larger amounts of sediment may be considered de minimis in relationship to location of the dam and the normal amount of erosion in the watershed, and thus may not require DA authorization. This guidance does not propose to set a specific amount of sediment that could be considered de minimis or “more than de minimis”. When evaluating whether any discharge is de minimis, or may be exempt from the Section 404 permit requirement under CWA Section 404(f)(1) exemption for dam maintenance activities, District Engineers should consider whether the discharge of dredged or fill material through the dam is necessary for dam maintenance, and proportional to the proposed activity and the size of the facility (i.e., size of the dam/structure and the surface acres and storage volume of the resulting impoundment). Other factors in this consideration should include the time of year and normal seasonality of high volume flows, the size of incoming and outgoing stream/river and the intended release volume, the natural hydrograph of the system, the speed of the drawdown, the normal amount of sediment in the watershed, and the potential for environmental harm. These factors should be documented as part of the decision regarding whether a DA permit will be required for the proposed release of sediments through a dam or would have been required in after-the-fact evaluations.

c. On a case-by case basis, District Engineers may consider the need to reduce the level of the reservoir through one or more flood gates and the resultant discharge of dredged material downstream, to avoid potential catastrophic dam failure, to be an emergency subject to the emergency permitting procedures found at 33 CFR 325.2(e)(1). Sluicing through a dam of less than 25 cubic yards of material may be authorized under Nationwide Permit 18, if all other conditions of that nationwide permit are met. Districts may also consider developing Regional General Permits for larger amounts of sediments to be released through a dam, if such Regional General Permits would include appropriate conditions to protect the environment and the overall public interest. Small impact releases of sediments might possibly be authorized under Nationwide Permit 23 if an agency has an approved Categorical Exclusion.

d. When discharging sediment from or through a dam or breaching a dam, reasonable measures should be implemented to reduce potential harm to downstream waters. Reasonable measures include, but are not limited to, prior dewatering by pumping or by releasing water from the upper control structures on a reservoir; mechanical dredging or excavation of sediments and appropriate disposal; timing releases to coincide with high water periods for better dilution; more frequent flushing to keep the discharges small; releasing a sediment amount that is dependent on the amount of water flow; and installing temporary barriers to prevent exposed sediments from being transported by runoff from subsequent storm events.

6. Duration

This guidance remains effective unless revised or rescinded.


Document: Regulatory Guidance Letter No. 05-04 (PDF)

FPL Energy Maine Hydro LLC v. FERC

287 F.3d 1151 (2002)

American Rivers, et al., Intervenors.

No. 99-1397.

United States Court of Appeals, District of Columbia Circuit.

Argued March 14, 2002.
Decided May 3, 2002.

1152*1152 1153*1153 Catherine R. Connors argued the cause for petitioner. With her on the briefs was Matthew D. Manahan.

1154*1154 Cynthia L. Amara was on the brief for amici curiae Clifton Power Corporation and New England Legal Foundation in support of petitioner.

Laura J. Vallance, Attorney, Federal Energy Regulatory Commission, argued the cause for respondent. With her on the brief were Cynthia A. Marlette, General Counsel, and Dennis Lane, Solicitor.

Daniel H. Squire and IJay Palansky were on the brief for intervenors American Rivers, et al.

Before: SENTELLE, ROGERS and GARLAND, Circuit Judges.

Opinion for the Court filed by Circuit Judge SENTELLE.

SENTELLE, Circuit Judge:

Petitioner FPL Energy Maine Hydro LLC (FPL), a hydroelectric facility, petitions this Court for review of two orders by the Federal Energy Regulatory Commission (FERC), the first determining that FPL is subject to licensing because the Messalonskee Stream on which FPL is located is “navigable” under 16 U.S.C. § 796(8), the second denying FPL’s request for rehearing. Because we find that FERC’s interpretation of the statute governing navigability is a reasonable one and that its navigability finding was supported by substantial evidence, we deny the petitions.

I. Background

The Messalonskee Stream (Stream) is a tributary of the Kennebec River (Kennebec) located in central Maine. It runs approximately ten miles from the Messalonskee Lake to the Kennebec, with four dams located along its stretch. The southernmost dam is the Union Gas Project, located approximately one mile up the Stream from the confluence of the Stream and the Kennebec. In between the dam and the Kennebec, beginning from the dam and progressing downstream, are two sets of rapids or “rips,” a bridge, a third set of rips, and two islands that together span approximately 200 feet downstream with a shallow shoal on the east side of the islands and a narrow and rocky channel on the west side. Below the islands the Stream widens and deepens as it encounters the backwater of the Kennebec. The Kennebec, itself a navigable water, empties into the Atlantic Ocean.

Pursuant to section 23(b)(1) of the Federal Power Act (FPA), 16 U.S.C. § 817(1), a non-federal hydroelectric project must be licensed if it is located on a navigable water of the United States, as defined by 16 U.S.C. § 796(8), or if other criteria not relevant to this case are met. Because the four dams constitute one development unit, if one project requires a license, then they all must be licensed. See Kennebec Water District, 80 FERC ¶ 61,208, 61,828, 1997 WL 438885 (1997). Thus if the Stream between the Union Gas Project and the Kennebec is deemed navigable pursuant to 16 U.S.C. § 796(8), all four projects require a license.

Section 3(8) of the FPA defines navigable waters as

those parts of streams … which either in their natural or improved condition notwithstanding interruptions between the navigable parts of such streams or waters by falls, shallows, or rapids compelling land carriage, are used or suitable for use for the transportation of persons or property in interstate or foreign commerce….

16 U.S.C. § 796(8). This means that, to be navigable for purposes of the FPA, a waterway must form a highway for commerce with other states or with foreign countries, by itself or by connecting with other waters. See The Montello, 87 U.S. (20 Wall.) 1155*1155 430, 439, 22 L.Ed. 391 (1874). Courts have determined a waterway to be navigable if “(1) it presently is being used or is suitable for use, or (2) it has been used or was suitable for use in the past, or (3) it could be made suitable for use in the future by reasonable improvements.” Rochester Gas & Electric Corp. v. FPC, 344 F.2d 594, 596 (2d Cir.1965) (emphasis in original), see also Marine Stevedoring Corp. v. Oosting, 398 F.2d 900, 908 n. 15 (4th Cir.1968), rev’d on other grounds, Nacirema Operating Co. v. Johnson, 396 U.S. 212, 90 S.Ct. 347, 24 L.Ed.2d 371 (1969); Sierra Pacific Power Co. v. FERC, 681 F.2d 1134, 1137-38 (9th Cir.1982). Navigability can be established based on any of these three requirements; each alone is sufficient. Rochester Gas, 344 F.2d at 596.

II. Proceedings Below

The Union Gas Project is currently licensed by FPL (as successor in interest to Central Maine Power Company — the original licensee of the project). The original license for the project was issued in 1968 and expired in 1993. Since that time, the project has been operating on annual licenses. As part of a jurisdictional examination of several projects for which licensing might not have been required,[1] the Office of Hydropower Licensing conducted a navigation report on the Stream in 1996. This report indicated that the Stream was not navigable because there was “no evidence of usage of the stream as a water highway, a continuous link for interstate commerce, either commercial or recreational, from above the project sites, past the projects, to the Kennebec River.” Following a review of comments to the report, the Acting Director of the Office of Hydropower Licensing issued an order finding that the Union Gas Project was located on a navigable waterway and therefore required a license. See Kennebec Water District, 79 FERC ¶ 62,041, 1997 WL 362917 (Apr. 21, 1997). On rehearing, FERC concluded the evidence submitted was inadequate to support a finding of navigability. See Kennebec Water District, 80 FERC ¶ 61,208, 1997 WL 438885 (Aug. 6, 1997). Following petitions for rehearing on that order, FERC set the issue of navigability for a hearing before an Administrative Law Judge (ALJ) to determine, among other things, the physical characteristics of the Stream, the difficulty associated with navigating the Stream, and the nature and frequency of actual use of the river for recreational boating. See Kennebec Water District, 81 FERC ¶ 61,073, 61,306, 1997 WL 698330 (Oct. 21, 1997). The ALJ, who did not address the physical characteristics of the Stream as they relate to navigability, found that the Stream was not navigable despite three “successful” and two “unsuccessful” canoe trips made for the purpose of litigation. See Kennebec Water District, 82 FERC ¶ 63,004, 1998 WL 9486 (Jan. 14, 1998). The ALJ also held that there was no evidence of “regular and substantial recreational use” to serve as a proxy for the simpler types of commercial navigation as allowed under United States v. Appalachian Electric Power Co., 311 U.S. 377, 61 S.Ct. 291, 85 L.Ed. 243 (1940). FERC trial staff and several intervenors in the proceeding below filed exceptions to the ALJ’s initial decision, which Central Maine Power opposed. Upon review, FERC concluded that the ALJ applied an incorrect legal standard by requiring evidence of “regular and substantial recreational use” for a finding of navigability. It therefore reversed the non-navigability finding and 1156*1156 required FPL to obtain a license. See Kennebec Water District, 84 FERC ¶ 61,027, 1998 WL 514602 (July 16, 1998). FERC based its navigability finding on the three “successful” canoe trips taken for purpose of litigation, as well as the physical characteristics of the Stream. Id. at 61,126. FERC denied FPL’s rehearing request and these petitions for review followed.

III. Analysis

This case requires us to answer two questions: first, whether FERC’s interpretation of “navigability” under the FPA was reasonable; second, if so, whether FERC’s navigability finding was supported by substantial evidence. We answer both questions affirmatively.

A. “Navigability” Interpretation

FPL argues that FERC departed from the statutory “suitable for use … in … commerce” test set forth at 16 U.S.C. § 796(8) (see also Rochester Gas, 344 F.2d at 596) and instead applied a mere “possibility of passage” test to determine whether the Stream is navigable. FPL contends that FERC conducted its navigability determination by looking only to three non-commercial, non-recreational test canoe trips that indicated it was possible to navigate downstream in unusual conditions, rather than looking to historical and present commercial or recreational use by average canoeists. FPL further contends that, in determining navigability, FERC deviated from its past precedent that requires more than just a showing of specialized, recreational boating where historical evidence of commercial use was lacking. FPL also faults FERC for relying on the flow created when the hydroelectric facility is generating to create navigability, as well as for failing to identify the commercial use to which the Stream could realistically be put.

We reject each of FPL’s arguments. Where an administrative agency is tasked with interpreting an ambiguous statute that it administers, a court will defer to that agency’s interpretation so long as it is reasonable. See Chevron U.S.A., Inc. v. Natural Res. Def. Council, Inc., 467 U.S. 837, 843, 104 S.Ct. 2778, 2782, 81 L.Ed.2d 694 (1984). As the statute does not define when a waterway is “suitable for use … in … commerce,” we assume that Congress intended FERC to address the ambiguity in the statute and develop an appropriate test. See United States v. Mead Corp., 533 U.S. 218, 229, 121 S.Ct. 2164, 2172, 150 L.Ed.2d 292 (2001). We find that FERC’s interpretation of navigability under the FPA, which was based on test canoe trips and the Stream’s physical characteristics in the absence of any commercial or recreational use, was reasonable and entitled to deference.

At the outset, we may quickly reject FPL’s argument that it was improper for FERC to rely on the flow created when the Union Gas Project is generating to create navigability. FPL confuses a finding of whether a waterway has always been navigable because an improvement could be made if reasonable in cost, with a finding of whether a waterway, together with its improvements, is presently “suitable for use.” See Rochester Gas, 344 F.2d at 596. The question before this Court is whether the Stream, with the presence of the Union Gas Project and the flow created when there is generation, is presently navigable, see Washington Water Power Co. v. FERC, 775 F.2d 305, 332 (D.C.Cir.1985), not whether the Stream was navigable prior to the Project’s construction. See id. at 331-32.

1157*1157 Turning next to FPL’s primary argument, FPL contends that FERC’s “possibility of passage” test: 1) ignored the fact that the Stream has never been used, either historically or presently, for commercial or private purposes, and 2) deviated from past decisions wherein FERC denied a finding of navigability when the only evidence of actual use was specialized, recreational boating.

All parties agree that the Stream has never been used for commercial traffic. But just because a body of water has not been used for commercial use does not mean that it is not susceptible to commercial use. See United States v. Utah, 283 U.S. 64, 82, 51 S.Ct. 438, 443, 75 L.Ed. 844 (1931). In Appalachian Power, 311 U.S. at 416, 61 S.Ct. at 303, the Supreme Court held that a lack of commercial traffic is not “a bar to a conclusion of navigability where personal or private use of boats demonstrates the availability of the stream for the simpler types of commercial navigation.” Thus without evidence of commercial use, FERC may look to other types of use to establish navigability.

In the past, FERC has often relied on evidence of recreational use as a proxy for commercial suitability. Here, however, there is no evidence of recreational use of the Stream. In fact, the only evidence indicating actual use of the Stream comes from the three trips made for the purpose of litigation. Echoing the ALJ, FPL argues that this evidence is insufficient to serve as a proxy for commercial suitability. Instead, FPL argues that FERC precedent requires a navigability finding to be based on “regular and substantial recreational use” in the absence of actual commercial use. We disagree. The statute and the case law make clear that evidence of actual use is not necessary for a navigability determination. “[T]he test [is] whether the river … is used, or capable of being used as a highway for commerce, over which trade and travel is or may be conducted in the customary modes of trade and travel on water.” Economy Light & Power Co. v. United States, 256 U.S. 113, 121-22, 41 S.Ct. 409, 412, 65 L.Ed. 847 (1921) (emphasis added). To determine whether a waterway is capable of being used as a highway for commerce, evidence other than recreational use may be considered. That is, recreational use may be the most common proxy evidence FERC relies on for findings of commercial suitability, but FERC has never taken the position, nor will this Court take the position now, that recreational use is the only proxy evidence on which FERC may rely. “Recreational boating is … of interest because it is boating, not because it is recreational. Any similar personal or private use not involving recreation, such as use of a river as a means of personal transportation, would be equally relevant to a determination of suitability for commercial navigation.” Kennebec Water District, 88 FERC ¶ 61,118, 61,304, 1999 WL 549672 (July 28, 1999). FERC may therefore, in the absence of commercial use, rely on evidence other than recreational use if that evidence is relevant to a finding of navigability. The Supreme Court has identified at least two types of evidence, declaring that the “capacity [of a waterway to meet the needs of commerce] may be shown by physical characteristics and experimentation as well as by the uses to which the streams have been put.” United States v. Utah, 283 U.S. at 83, 51 S.Ct. at 444. In the absence of any “uses to which the [Stream] ha[s] been put,” FERC acted consistently with Supreme Court precedent in relying on the three test canoe trips.

FPL nonetheless argues that the test trips were of a type of specialized, recreational boating that FERC has previously 1158*1158 disregarded when making navigability determinations. The cases on which FPL relies, however, are distinguishable from the facts before us. For example, in Pennsylvania Elec. Co., 56 FERC ¶ 61,435, 62,549-50, 1991 WL 297437 (1991), FERC determined a river was non-navigable because a substantial reach of the river could only be navigated by a kayak (or comparably specialized sporting craft designed for river running) maneuvered by an expert paddler. Similarly, in PacifiCorp Elec. Operations, 73 FERC ¶ 61,365, 62,140, 1995 WL 756395 (1995), rehearing denied, 74 FERC ¶ 61,262, 1996 WL 89781 (1996), FERC determined that a waterway was non-navigable because “all of the evidence of use or suitability for use for recreation concerns use by skilled kayakers or whitewater rafters.” FERC held that “[t]his is not the sort of recreational boating that [it] has recognized as demonstrating the suitability of a river for the simpler types of commercial navigation.” Id. at 62,140-41. The river in PacifiCorp included Class IV rapids that could not be navigated easily without a specialized boat. In the present case, the Stream at most contains Class II rapids that were successfully crossed by a canoe. FERC has repeatedly found waterways to be navigable that may be traversed by a canoe — a simpler type of commercial transportation. See, e.g., Appalachian Power, 311 U.S. at 415-16, 61 S.Ct. at 303. We therefore find that FERC did not depart from precedent when it relied on successful test trips taken in canoes.

FPL further argues that FERC’s navigability test was flawed because FERC failed to identify the possible commercial use to which the Stream may be put. We see no reason why FERC must identify the precise commercial use to which a previously unused waterway may be put in order for the Commission’s finding of navigability to be upheld. The test is whether the waterway is presently “suitable for use for the transportation of persons or property in interstate or foreign commerce,” not whether the waterway is presently suitable for a specific type of commercial activity named by FERC and approved of by an opposing party. 16 U.S.C. § 796(8); see also PacifiCorp, 73 FERC at 62,140, 1995 WL 756395 (“[I]n order to demonstrate that the [waterway] at the project site is a navigable water, [FERC] need only find that it was or is used or suitable for use to transport persons or property between the project site and [another navigable water].”). Consequently, if the evidence in the record supports a finding that the Stream is suitable for transporting persons or property to the Kennebec, then this Court will uphold such a finding without adding a requirement that FERC identify a specific type of commerce associated with the transportation of persons or property. The language of the statute does not require such a finding; neither do we.

Even more important to our analysis, FERC did not rely on the test canoe trips alone when finding that the Stream was navigable. FERC also looked to the Stream’s physical characteristics when making its navigability determination. See United States v. Utah, 283 U.S. at 83, 51 S.Ct. at 443-44. Thus absent evidence of commercial or recreational use, FERC properly relied on both “physical characteristics and experimentation” to determine whether the Stream was suitable for use in commerce. Id.

For the reasons stated, we find that FERC’s interpretation of the FPA’s navigability test was reasonable insofar as it necessarily relied on test canoe trips and the Stream’s physical characteristics in the absence of past or present commercial and 1159*1159 recreational use of the waterway. It is therefore entitled to deference.

B. Substantial Evidence

As our discussion of FERC’s deference-worthy interpretation of the navigability test may suggest, we also conclude that FERC’s finding of navigability is supported by substantial evidence. 16 U.S.C. § 825l(b) (“The finding of the Commission as to the facts, if supported by substantial evidence, shall be conclusive.”).

The “experimental” test canoe trips provide sufficient evidence that the Stream is navigable. Three witnesses, all with differing interests in the litigation, successfully navigated downstream without incident, and two attempted and succeeded in navigating upstream, albeit with some difficulty. Although FPL made much of the difficulty associated with this upstream travel both in its brief and at oral argument, FPL failed to provide any explanation as to why an upstream trip — either made with ease or with difficulty — is necessary for a navigability finding when the evidence of successful downstream trips is clear. Nowhere in the statute or accompanying case law does it state that the transport of persons or property in interstate or foreign commerce must include two-way transport. We do not view this case as an opportunity to suggest otherwise.

In addition to relying on the three test trips, FERC made a separate determination that the physical characteristics of the Stream rendered it suitable for commercial navigation. The Supreme Court has held that a water’s “capacity [for commercial navigation] may be shown by physical characteristics and experimentation as well as by the uses to which the streams have been put.” United States v. Utah, 283 U.S. at 83, 51 S.Ct. at 444. And in Montana Power Co. v. Federal Power Commission, 185 F.2d 491, 495 (D.C.Cir.1950), this Court declared that “[i]f the stream’s flow, depth, gradient, width and capacity make it `suitable for use’ in interstate commerce, it is subject to the licensing authority of [FERC].” In other words, a waterway may never have been used for transportation, commerce, or recreation, but nonetheless may be suitable for interstate commerce (and subject to licensing by FERC) based on its physical characteristics. See Loving v. Alexander, 745 F.2d 861, 864 (4th Cir.1984) (“The extent and manner of use of a navigable river is not important as long as it is usable as an actual avenue of commerce.”).

The record includes sufficient evidence regarding the Stream’s physical characteristics on which FERC relied in making its navigability determination. FERC noted that the Stream has a very slight gradient, has a depth of approximately three and a half to four feet when the dam is generating (although slightly shallower around the two islands), is wide enough to support passage up and down the Stream and around the two islands, and has few obstacles (e.g., boulders and fallen trees) that a canoeist may steer around without difficulty. Kennebec Water District, 84 FERC ¶ 61,027, 61,125-26, 1998 WL 514602 (July 16, 1998). There is nothing in the record to suggest that the Stream’s physical characteristics preclude navigability when the dam is generating other than a water depth around the islands that is lower than the rest of the Stream. But the same record includes evidence that the three canoeists successfully navigated down the Stream and past the islands. For reasons already stated, the difficulty experienced by one of the canoeists traveling upstream past the islands does not negate the otherwise sufficient evidence. Moreover, even though the dam does not operate all the time, thereby rendering the water level too low 1160*1160 to navigate year round, navigability need not be available “at all seasons of the year, or at all stages of the water.” Economy Light & Power, 256 U.S. at 122, 41 S.Ct. at 412.

FPL attempts to bolster its argument with evidence that the test trips upon which FERC relied were made during periods of unusual water conditions. FPL argues that this should negate FERC’s navigability finding. That is, FPL argues that since “susceptibility of use as a highway for commerce should not be confined to exceptional conditions or short periods of temporary high water,” the canoe test trips do not show the stream to be navigable. Loving, 745 F.2d at 865; see also United States v. Utah, 283 U.S. at 87, 51 S.Ct. at 445. True, the evidence indicates that two of the test trips took place during periods of high water, but that same evidence indicates that the remaining test trip took place during a period of low water. FPL’s witness navigated up and down the Stream when the Kennebec’s flow was 4030 cubic-feet per second (cfs) (down from its average flow of 5000 cfs), an event which would have reduced the backwater effect from the Kennebec and lowered the already low depth of water around the islands. This is sufficient evidence that the Stream can be navigated both up and downstream during non-optimal water levels.

We acknowledge that the evidence of navigability is not overwhelming. But to uphold FERC’s navigability determination, we need only find that the evidence on which the finding is based is substantial. 16 U.S.C. § 825l(b); see Consolidated Hydro, Inc. v. FERC, 968 F.2d 1258, 1261 (D.C.Cir.1992). The “substantial evidence” standard requires more than a scintilla, but can be satisfied by something less than a preponderance of the evidence. See Whitmore v. AFIA Worldwide Ins., 837 F.2d 513, 515 n. 4 (D.C.Cir.1988). We therefore find that the test trips, together with the Stream’s physical characteristics, constitute substantial evidence to support FERC’s finding of navigability.

IV. Conclusion

FERC’s reliance on test canoe trips and the physical characteristics of the Stream, in the absence of historical or present commercial or recreational use, is a reasonable interpretation of the navigability test set forth in the Federal Power Act and is therefore entitled to deference by this Court. Moreover, the record includes substantial evidence to support FERC’s navigability finding. Three witnesses were able to successfully navigate down the Stream, and the physical characteristics of the Stream support a finding of navigability. For these reasons, the petitions for review are denied.

[1] Union Gas was previously required to be licensed pursuant to FERC’s incorrect interpretation of a different section of the FPA.

Source: FPL Energy Maine Hydro LLC v. FERC