Final Environmental Impact Statement Excerpts
We modeled three drawdown regimes: (1) the 4- and 10-foot drawdown regime proposed in the Yadkin Settlement; (2) the 4- and 6-foot drawdown regime recommended by SaveHighRockLake.org; and (3) the 2 –foot year-round drawdown regime recommended by Richard Martin. The proposed and two alternative drawdown regimes encompass the set of possible regimes suggested by stakeholders.
The two alternative drawdown regimes would result in generally more water being retained in High Rock reservoir, water that could be used to supply downstream flows during drought conditions. However the most likely months for limited inflow are the months of June, July, August, September, and October, which would limit the effective difference between the Yadkin Settlement and SaveHighRock.org. Therefore, there would not be a substantial difference between the two alternatives in the ability to meet the minimum flow requirements or the implementation of the Low Inflow Protocol.
These alternatives also would reduce flood storage capacity at High Rock reservoir, as well as diminish the ability to use High Rock reservoir to attenuate the incoming flood events. Many of the severe flood events in the Yadkin and Pee Dee River basin are the result of summer or early fall tropical storms and hurricanes, during which the storage at High Rock reservoir does not play a substantial role in flood control. Therefore, the loss of storage capacity would only be noticeable in the months of November through February, and during small to medium flood events.
Within the Yadkin Project, wetlands are most prevalent at High Rock reservoir where they make up about 29 percent of the cover types within 200 feet of the reservoir, SaveHighRock.org’s recommended High Rock operating regime of 4 foot drawdowns during the growing season and 6 foot winter drawdowns would affect wetlands similarly to the proposed operating regime. Because the winter drawdown would be less severe than the proposed drawdown with only a 2-foot difference between winter elevation and the elevation for the remainder of the year, some additional emergent and submergent wetland vegetation would likely become established within this drawdown zone.
We conclude that the higher lake levels and extended recreation season would result in enhanced recreational opportunities that could result in increased recreational use of the reservoir. An increase in recreational use would result in increased recreational spending and associated increased incomes of recreation-related businesses. Because the recommendations of other parties would yield even higher lake levels during at least some parts of the year, they would tend to incrementally increase recreational use and recreational spending by more than Alcoa Generating’s proposal.
We conclude that the higher lake levels and extended recreation season would increase the value of nearby properties, which would in turn increase related property tax revenues. Because other parties’ recommendations would yield even higher lake levels during some parts of the year, they would tend to incrementally increase property values and property tax revenues by more than Alcoa Generating’s proposal, although the magnitude of the difference has not been estimated.
Reservoir Level Management
High Rock Reservoir
Settlement parties and other stakeholders are in agreement with the proposed water level regimes at all Yadkin and Yadkin-Pee Dee River Project reservoirs with the exception of High Rock. Drawdown restrictions on High Rock reservoir would limit available water, especially during low inflow, that Alcoa Generating could use to meet minimum flow requirements downstream at the Falls development. However, our modeling results show that the combination of proposed restrictions on drawdown and minimum flow requirements would almost always be achievable. The exceptions are only during drought conditions, during which operations would be covered under the proposed Low Inflow Protocol, also part of the settlement agreements.
The proposed minimum flow for the Yadkin Project also would be achievable under the two alternative drawdown regimes suggested by SaveHighRock.org and Mr. Martin. However, these two alternatives would reduce flood storage capacity at High Rock reservoir and diminish the ability to use High Rock reservoir to attenuate incoming flood events. Many of the severe flood events in the Yadkin and Pee Dee river basins are the result of summer or early fall tropical storms and hurricanes, during which the storage at High Rock reservoir does not play a substantial role in flood control. Therefore, the loss of storage capacity would be noticeable in November through February and during small to medium flood events. Also, at a higher lake level, some additional flow over the spillway would be lost from potential generation at the High Rock powerhouse. Finally, because High Rock reservoir is the primary storage reservoir in the Yadkin Project, and the downstream powerhouses have maximum hydraulic capacities similar to that of the High Rock powerhouse, additional generation losses would occur at all three Yadkin developments under the 6-foot winter drawdown as compared to the 10-foot drawdown. Because the four Yadkin Project reservoirs have been experiencing similar (or greater) drawdowns for many years and continue to support excellent sport fisheries, we conclude that the proposed drawdown restrictions would adequately protect fishery resources throughout the year. Because drawdown restrictions during the spring spawning period are tied to the elevation of the reservoir in April, the beneficial effects on shoreline nest-building fish species would be the same under the proposed and alternative drawdowns.
The proposed and alternative operating regimes would result in changes in the distribution of wetland types including the loss of black willow wetlands on the delta sediment bars that would likely be replaced by emergent vegetation over time. Water willow would likely expand within High Rock reservoir and emergent vegetation would likely expand around the reservoir shoreline, increasing the amount of fish and wildlife habitat available. Limiting the winter drawdown to 10 feet would protect a greater portion of the reservoir from freezing and desiccation, limiting adverse effects on overwintering reptiles and amphibians. A year-round 2-foot drawdown alternative would result in the greatest loss of forested and scrub-shrub black willow wetlands because the majority of them would be inundated permanently. This alternative would result in the loss of a large majority of fish spawning habitat associated with the black willow wetlands; however, emergent marsh and aquatic bed wetlands would increase throughout the reservoir because of the stable water elevations, which would increase the amount of fish and wildlife habitat available.
Summertime water levels would be higher at High Rock reservoir than under existing conditions for both the proposed and two alternative water level regimes. While the two alternative water level regimes would allow private dock owners greater access to the water during the winter months, only 13 percent of the recreational boating occurs during the winter months. Also, under the Proposed Action, 5 of the 7 public boat ramps would be accessible at the 10-foot winter drawdown. Therefore, the proposed water level regime would enhance recreational boating during the summer when demand is the highest and would slightly improve boating access to High Rock reservoir during the winter months over existing conditions when usage is considerably less.
In summary, the proposed water level regime at High Rock reservoir would provide slightly more flood storage capacity than existing conditions during the winter months, allow for more generation than the two alternative proposals also during the winter months, expand the amount of shoreline fish and wildlife habitat, reduce adverse effects on overwintering reptiles and amphibians, and extend the summer recreation boating season by 3 months during the time of highest public use and benefit the local economy. These benefits would be worth the estimated annual cost of Alcoa Generating’s proposed water level and minimum flow regime under the Yadkin Settlement of $308,530, and would be attained at far less cost than the two alternative water level and minimum flow regimes that would cost $434,670 with a winter water level within 6 feet of full pond and $7,632,610 with a year-round water level within 2 feet of full pond.
The Yadkin Settlement includes proposed land conveyances for 2,310 acres of non-project lands adjacent to High Rock reservoir; 2,420 acres of non-project lands adjacent to Tuckertown reservoir, and 1,085 acres of non-projects lands at Morrow Mountain State Park. In addition, Alcoa Generating would donate to Rowan County 63 acres of non-project lands currently being leased to Rowan County as part of the Eagle Point Preserve; 270 acres of non-project lands located adjacent to the Narrows and Falls reservoirs to the Forest Service for inclusion in the Uwharrie National Forest; and 14 acres adjacent to the existing Badin Boat launch access area to the town of Badin for development as a public park. We reviewed the location and use of these parcels and concluded that none of these lands, which are currently not within the project boundary, are needed for project purposes and would not require Commission oversight or inclusion in any new license (see section 3.3.8, Land Use and Aesthetics). These land transfers would occur outside the scope of any new license issued for the Yadkin Project.