Mitigation of Project Impacts 

The Woronoco dam is located below 95% of the habitat suitable for spawning Atlantic salmon on the Westfield River.  That is, only 5% of the available Atlantic salmon habitat of the Westfield River lies below the Woronoco dam and it cannot be reached by upstream migrants because of the first dam on the river.  Thus, the MA Division of Fisheries and Wildlife (MADFW) trap upstream migrants in a trap and truck system to stock Salmon hatcheries.  After spawning, the fry that are placed in the upper tributaries of the river.  (MADFW’s report of June 4, 2004 provides details about the actual number of spawning units of stream habitat and their location on the Westfield River).  After 1-3 years in the upper tributary habitat, the smolt must migrate down river to the Connecticut River and the ocean.  Four of the five dams on the Westfield River have active downstream fish passage facilities in operation. The fifth dam is being licensed and will soon have a similar passage system.  All these passage facilities must undergo tests to find the most effective design for increasing successful passage.

In its July 10, 2003 letter, MADFW states that while “the applicant sees no incremental impact to wildlife as a result of restoration and operation, the Division believes that addition of another operating hydroelectric project on the Westfield River will have impacts on fish and wildlife.  Even a well constructed downstream fish passage system will not be 100% effective – leading to some loss of downstream migrants.  And while the installation of an upstream ellway will be an asset, adult ells are very difficult to guide around turbines and significant losses could be experienced.”  Indian River grants that no fish passage is perfect, nor is an unimproved dam effective in passing 100% of migrants on the river.  Moreover, this comment also singles out wildlife impacts, but gives no example in the letter from MADFW dated July 10, 2003.  During discussion held on site, no further example of impacts on fish or wildlife resources was suggested.  Instead, consultation focused on how to make downstream passage for Atlantic salmon a more effective mitigation and where to install up and down river eel passage facilities, as well as pointing out that only one Atlantic salmon was trapped at the DSI dam, the first dam on the river in each of the last three years.  So, the focus of the agencies is to make the whole river system easier for fish passage as the best way to get the smolt down to the sea and back up in future generations to rebuilt natural spawning for the Atlantic salmon.

As recommended during site consultation, the location and design of discharge flows into the bypass for habitat maintenance is best determined once the plant is operating. Both the USFWS and MADFW recommend that Indian River conduct a flow study the first field season following project start-up in order to determine a suitable discharge to protect the resources of the bypass reach.  The average river flow at the dam is 618 cfs and the installed hydraulic capacity is only 543 cfs.  On average, 55% of the river water spills over the dam without going through the tur­bines (probably more in the past due to manual setting of wicket gate openings where cycling the pond may have been a problem). 

This plant will be automatically  operated in a run-of-river mode. When inflow is equal to or less than the hydraulic capacity of the power plant, generating flow is throttled to maintain a stable impoundment elevation above the dam plus a constant by-pass flow and discharge through the fish passage as seasonally required.  Flows greater than the hydraulic capacity plus the bypass and fish passage discharges are spilled over the dam. This is sim­ilar to the Woronoco plant (FERC 2631), three miles downstream of Russell dam, where automatic pond level controls have been installed.  Similar controls are proposed by Indian River, including stopping all generation whenever inflow to the impoundment is less than the total of (1) the minimum capacity of the smallest turbine, plus (2) the fishway flows, plus (3) any additional bypass flow required to be discharged to the bypass reach.

In correspondence with USFWS, Engineer Dick Quinn proposed locating a downstream fish passage facility for Atlantic salmon smolt in the dam and flashboards immediately adjacent to the west end of the gatehouse, with a plunge pool below and a channel or sluiceway to carry downstream migrants over the ledge to the tailrace pool.   Conceptual designs for both the 10’ deep lead that guides migrants across the forebay to the fishway and the cut in the flashboards and a stoplog gate to be set in the crest of the dam, plus the layout of a channel to the tailrace are shown in the USFWS drawing found in Appendix D.

The other impact on fish migration comes from the trashracks.  Hydro operators think of racks as deterrents of fish mortality, but resource managers view racks not as screens, but as a potential point of impingement for migrating fish. The trashrack structure creates a filtered barrier between the Westfield River and the penstock intakes preventing debris (and most fish) from entering the penstocks and damaging (or being damaged by) the turbines. The trashracks span the entire 44-foot width of the river side of the gatehouse.

The racks are constructed of 384 pieces of mild, cold rolled, steel bar stock. Each steel piece is 10 ½ feet long, 3” wide and 3/8 inch thick. The bars are constructed in 3’ wide panels for ease of handling. The panels are formed in a wooden jig. Bars have 7, ¾ inch, holes punched through them, spaced 3” in from either end and at 18” centerline spacing. The first bar has 7 pieces of ¾ inch threaded rod welded to it. It is placed in the jig with the threaded rods facing vertically upwards. Pipe spacers have ¾” inside diameter and 2” long are slid onto each of the 7 threaded rods. A second piece of bar stock is slid onto the threaded rods and more spacers installed. This process is repeated until the last bar is slid on with enough threads left protruding to install and tighten down 7, ¾ inch nuts. The nuts are then welded into place.

The panels are placed at an 80-degree angle to the floor of the intake. They are set into a slot in the concrete to prevent them from moving. The invert of the rack slot is at el. 258.5. The 10.5 foot length of the rack panels and 80-degree angle sets the top of the racks at 268.5 msl, which is the elevation of the crest of the auxiliary spillway next to the gatehouse.  Since the raking platform is at 275.5 msl., the space between the top of the racks and the trashrack deck is blocked by a timber bulkhead made of four inch, tongue and groove, oak deck planks. These planks are also set at an 80-degree angle to allow for a smooth transition between the racks and the raking deck. This smooth transition is required so that the wheels of the Smith-Leonard Trash Rake can roll easily in and out of the water.

ii.  Agency Recommendations

Key recommendations provided by both MADFW and USFWS to mitigate impacts on fish resources include:

Project will furnish upstream and downstream passage for American eels designed in consultation with FWS and MADFW within 1 year of exemption issuance (DWF 7/804).

The project will provide downstream fish passage for Atlantic salmon adults and smolts. The passage is to be designed in consultation with FWS hydraulic engineers. The facility concept was designed by FWS, see Appendix D.  It is similar to the design operating and soon to be tested at Woronoco Hydro (FERC 2631) and will operate from April 1 to June 15 and Nov. 1 to Dec. 31.  MADFW says within 1 year, USFWS says at start-up.

The project shall participate in the trap and truck program for restoration of the Atlantic salmon on the Westfield by paying ¼ of the cost of the program that moves adult salmon from a trap at the first dam on the Westfield River (FERC 2608) to spawning habitat above the fourth dam (FERC 2986).

The project will have to construct upstream anadromous fish passage facilities at this project when and on a schedule proposed by the FWS and/or MADFW.  Until a bypass discharge plan has been completed, 50 cfs will be discharge to the bypass reach, including the flow used for the fish passage facilities on each side of the dam.

iii.  Downstream Fish Passage and Eel Passage Plans Proposed by Applicant

Indian River accepts all of the fish passage mitigations recommended by the resource agencies.  Restoration of the flashboards on the dam will start with the downstream fish passage facility described in Appendix D.  Early consultation stated that the facility must be operational before the commencement of operations at the hydro project, but the letter from MADFW dated  July 8, 2004 states that downstream fish passage shall be operational within one (1) year of exemption issuance.  To summarize: to protect fish resources the applicant will (a) construct, operate and maintain fish passage facilities for downstream passage of smolt and adult Atlantic salmon and up and downstream passage facilities for American eel, (b) provide a continuous flow to the bypass reach, part from the fish passage facilities on the east side of the dam, part for the eelway on the west side and part from a notch in the flashboards on the west side of the dam to maintain habitat in the short riffle so long as it includes macroinvertebrate resources that support fish culture and (c) maintain a stable headpond (through run-of-river operation) to benefit resident impoundment species.

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