Project Name: Gemini Solar Project
Responsible Agency: US Army Corps of Engineers - Regulatory
Cooperating under FAST-41
Cooperating under NEPA
Action Outcome: Permit issued/verified
The applicant is proposing to discharge fill material into 0.78 acre below the ordinary high water mark of 30 ephemeral drainages for the construction of interior access roads and connector roads associated with 71 single and complete linear projects on 7,079 acres of Federal lands administered by the Bureau of Land Management (BLM). The 71 single and complete linear projects are associated with the construction of a 690 megawatt alternating current (MWac) solar facility being evaluated by BLM. The proposed roads would consist of a combination of access road crossings. The interior access road design would consist of recompacted native material and a concrete cutoff wall on the downslope side to prevent the access road from eroding during storm events. The cut-off walls would be approximately 8-inches wide and 3-feet deep. The proposed connector roads would consist of an aggregate base and concrete cut-off walls on either side. The connector causeway roads between areas would be designed as Arizona-style crossings with a concrete base throughout the feature to maintain road integrity during storm events. A concrete cut-off wall would be constructed on either side of the causeways and would be approximately 8-inches wide by 3-feet deep. Six inches of Type II aggregate base would be discharged below the concrete layer. No culverts would be installed for the proposed crossings, and no crossings would result in a reduction in the bank full width of the ephemeral drainages. The proposed discharge of fill material into waters of U.S. associated with the proposed road crossings range from between 0.001 acre and 0.11 acre. The applicant has not proposed compensatory mitigation for the proposed actions.
The applicant is also proposing to install up to 9,035 pilings (6 by 4 inches) into ephemeral drainages greater than 3-feet wide. All pilings would be installed using pile drivers affixed to small tracked vehicles or utility trucks. No concrete would be used during installation of the pilings, and no pilings would be placed in ephemeral drainages where the width (based on the ordinary high water mark) is less than 3-feet. The proposed pilings would not have the effect of a discharge of fill material, and therefore do not require a permit under Section 404 of the Clean Water Act.
We expect to render a decision within approximately 15-days of receiving the 106 NHPA compliance documentation from the BLM and the Biological Opinion from the USFWS. BLM, the lead Federal agency, has indicated that delays have occurred with 106 NHPA compliance, and identified via email on January 16, 2020, that they anticipate the Section 106 consultation will be completed on March 31, 2020. Therefore, the date of final verification was April 20, 2020. However, since the Corps' action is dependent upon BLM's completion of Section 106 of the NHPA, if BLM's schedule shifts, the Corps' milestone will be revised accordingly. Subsequently, in March 2020, BLM was unable to provide the Corps with a new estimated target date for the completion of the 106 process. The Corps cannot make further progress on the 404 review until the Sec. 106 compliance documentation is received from BLM. Since the Corps cannot estimate a new target date for the completion of the 404 action and cannot make further progress on the 404 review, the 404 action is paused until BLM is able to estimate a new target completion date for the 106 process or the Corps receives documentation of 106 compliance from BLM.