Lake Tomahawk Dam Repairs

Submit Written Questions No Later Than September 8, 2023 5:00 p.m. Total Project Completion Date June 30, 2024 or earlier Lake Tomahawk Dam is an earthen dam in Black Mountain, North Carolina located along the southern edge of Lake Tomahawk. The dam is classified as a High Hazard Dam. Minor seepage is occurring following the removal of a tree on the embankment in 2014. Erosion and sediment control, toe drain and blanket drain construction, articulating concrete block overtopping protection, and earthworks construction will be constructed. Each proposal must be accompanied by a bid bond of five percent (5%) of the gross amount of the proposal executed by a Surety company licensed under the laws of North Carolina to execute such bonds. The Successful Bidder will be required to furnish a Construction Performance Bond and a Construction Payment Bond as security for the faithful performance and the payment of all bills and obligations arising from the performance of the Contract The Town of Black Mountain Council reserves the right to reject any or all bids. The Town of Black Mountain is not liable for costs associated with preparation of the bid. Work of the Project includes and consists of furnishing all labor, materials, supervision, equipment and services necessary to complete the repairs of the Dam and all associated facilities and structures. The work will include the following: 1) Perform work in accordance with the Project Documents (Drawings and Technical Specifications), and requirements of North Carolina Erosion and Sediment Control Planning and Design Manual. 2) Obtain necessary permits. 3) Attend pre-construction meeting and project meetings. 4) Contact utility location service including contacting NC 811 in accordance with state requirements. 5) Relocate existing power lines and poles in conflict with proposed articulating concrete block revetment system to upstream crest of dam as coordinated with Town of Black Mountain. 6) Install required Erosion and Sediment Control (E&SC) measures, maintenance of measures, and removal after site stabilization. 7) Remove and replace fencing at entrance and laydown area. 8) Install temporary construction access fencing around work area. 9) Install temporary access control fence and gate at existing gravel parking lot entrance. Fencing shall be removed and areas stabilized upon completion of the Work. 10) Maintain dewatering pump on-site for temporary dewatering. 11) Remove vegetation and topsoil from construction area for blanket, toe drain, and articulating concrete block revetment construction. 12) Excavate for toe drain to required grades and stockpile any suitable soil for re-use. Remove excess materials from the site. 13) Remove vegetation and soil material not meeting project specifications from the site. 14) Stockpile topsoil material for re-use if suitable for re-use. 15) Excavate for the toe drain. The excavation length will be limited to that which can be excavated and backfilled within one day. 16) Install and maintain temporary dewatering measures. 17) Place compacted fine aggregate, coarse aggregate, and piping for drainage blanket and toe drain. 18) Perform temporary dewatering to maintain water level below excavations to prevent softening of excavation bottom and sides. 19) Install concrete toe drain outlet pad and rat guard. 20) Fine grade existing embankment surface and scarify and compact soil subgrade to provide a firm subgrade surface for C-33 fine aggregate placement. 21) Install and compact C-33 fine aggregate as underlayment for articulating concrete block and blanket drain. 22) Install non-woven geotextile as separation between C-33 fine aggregate and articulating concrete blocks. 23) Install coarse aggregate bedding layer for articulating concrete block. 24) Install geogrid reinforcement over coarse aggregate bedding. 25) Install articulating concrete block mats and provide C33 fine aggregate infill in blocks. 26) Cover articulating concrete block with minimum 6-inch thick soil layer for vegetation growth. 27) Perform record survey of work by licensed land surveyor including blanket and toe drain location and pipe invert elevations (obtained prior to aggregate placement), outlet location, and limits of work and submit to the Owner and Engineer within two weeks after completion of work. The record survey will be performed in conjunction with the drain installation and 01100 - 4 Summary will require more than one site visit by the registered land surveyor to document drain locations and final repair geometry. 28) Stabilize all disturbed areas. 29) Replace fence section that was removed. 30) Repair gravel parking area. 31) Remove temporary access fence and gate and stabilize area. 32) Attend pre-closeout meeting with Owner and Engineer to address remaining work (punch-list) items. 33) Attend final closeout meeting with Owner and Engineer to verify remaining work items are complete. 34) Maintain E&SC measures until site is stabilized. 35) Remove E&SC measures after site is stabilized. 36) Site construction is considered complete (with exception of any warranty items) when the site is stabilized and E&SC measures are removed. 37) Perform repairs, if necessary, in accordance with contract warranty provisions. B. Perform Work of Contract under stipulated sum with Owner in accordance with Conditions of Contract. C. Work of Contract shall be constructed to the lines and elevations as shown on the Drawings and as identified in these Technical Specifications. Any deviations from the Drawings or Technical Specifications require the prior written approval of the ENGINEER and must be documented by "record" revisions to the Drawings and/or Technical Specifications. D. During all phases of construction, construction will be tested, monitored, and evaluated prior to approval.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.