圖書典藏及影音數位平台

依據民國97年度辦理「烏溪鳥嘴潭攔河堰初步規劃」之成果，鳥嘴潭攔河堰位於烏溪橋上游5公里處，利用烏溪南岸土地規劃一離槽人工湖，用以蓄豐濟枯。初步評估人工湖蓄水容量1,700萬立方公尺，已達行政院環保署民國95年2月20日修正發布「開發行為應實施環境影響評估細目及範圍認定標準」第12條第1項第3款之規定，即在自來水水源水質水量保護區內堰壩高度7.5公尺以上或蓄水容量250萬立方公尺以上者，應實施環境影響評估。本(99)年度工作係延續98年度調查成果，並配合工程可行性規劃內容，持續進行計畫區之環境資料蒐集調查，以評估烏溪鳥嘴潭人工湖設立後對周遭環境之影響。

In order to meet sustainable utilization of resources and the mid-tern and long-term domestic water demands in Zhang-Hua and Nan-Tou regions, the Wu River water resources were planned to be developed in first priority. The evaluation results of Wu River water resources development project indicated that the most feasible plan is to construct a weir coupled with a man-made storage lake. Therefore, a preliminary planning of Nio-Zui-Tan weir was commenced in 2007 to survey and evaluate weir site, surface geology and regional groundwater for evaluation development scheme and weir layout. The preliminary plan set the Niao-Zui-Tan weir at 600 m downstream of Yan-Feng Bridge and a man-made off stream lake along south bank off Wu River adjacent to the proposed weir site. The development plan, upon completion, could replace portion of groundwater resources withdraw from Zhang-Hua and Nan-Tou regions to provide opportunity for groundwater recharge and restoration. The weir is planned for a fixed concrete type to increase water storage for stable water intake. The weir uses lateral intake and equips with sediment sluiceway The man-made lake utilizes the land along south bank of Wu River and extended toward south to the foot hill of Bei-Shi-Nan without interference with highway NO.6, regulation limit of Wu River and Ai-Liao fault. The artificial lake includes seven ponds with a total area of 125 ha and effective storage of 14,500,000 m3. According to the regulations published be EPA in 2009, EIA should be conducted for volume of any storage pond larger than 5,000,000 m3. Therefore, the project entitled “The feasibility planning of Niao-Zui-Tan artificial lake along Wu River-Environmental Impact Assessment” was extended for the second year in 2010 to assess impacts of the man-made lake to the surrounding environments and to complete the EIA work. Works of this project in the first year included mainly detailed survey of background information. In addition to survey further background information, the environmental impact assessment works are commenced in this year( the second year of the project). The basic requirements of background information survey include meeting EIA regulations, obtaining environmental information at representative site, and complete records of hydrology and water quality of both wet and dry seasons. The background information are established by field survey and collation of background information in the surrounding areas including analyses of environmental sensitivity zones. The background information are used form impact prediction of the project to provide adequate precaution or mitigation measures, as well as feasible environmental protection measures, monitoring program or alternatives to minimize all possible impacts caused by implementation of this project. The existing environmental qualities and characteristics of the project area are as follows: 1. Air quality: The analyzed results of field survey and collected data indicate that all air quality items are lower than standards for all survey sites except O3 of maximum 8 hours. 2. Noise and vibration: All measurements at all monitoring sites meet noise control standards except noise at Shi-Xiang-Shan farm monitoring site caused by inset in the night time and Freeway NO.6 caused by traffic in holidays. 3. Surface water: In general, water quality is classified as slight to medium polluted mainly caused by high suspended solid. However, all water quality monitoring items meet class B water quality standards except BOD, SS, TP and E-coli. For water quality upstream of the proposed weir, all monitoring items meet drinking source water quality standard, except one measurement that Pb, Cr, and E-coli exceeded standard. 4. Groundwater: The groundwater table around the proposed man-made lake site is 3~10 m below ground surface. The flow direction of groundwater is similar to ground topography from terrace in the south toward north to river valley. Monitoring results indicate that NH3-N, E-coli and TOC exceed drinking water source water quality standards, and Cl-, NH3-N. heavy metals( Fe, Mn) of some monitoring sites exceed the standards of the first category ground water. The monitoring results indicated that groundwater quality around the proposed man-made lake has high organic content caused by irrigation water and domestic waste water. 5. Soil: The project area has slightly acid soil caused by long time farming activities and over application of fertilizers, however, all heavy metal concentrations are lower than standards and there is no indication of foreign pollution. 6. Traffic service level: There are East Cao-Tun connection road, Provincial Highway NO.3, Provincial Highway NO.14, County Route NO.6, Yu-Ping Alley, Dong-Chi Road and some access roads around the project area. All roads have A class service level except County Route NO.6 and Dong-chi Road( A~B class) due to insufficient road width. 7. Territorial plants: There are mostly river bed and farmland within the survey boundary. Vegetations are rice, asparagus, bamboo, tomato, banana, litchi, bell fruit and hibiscus. 8. Territorial animals: Animals within the survey boundary are mostly those common species live in the plane and low elevation hills and there is no dominate species. However, there are three preservation species of the second class (Spilornis cheela, Otus bakkamoena and Falco tinnunculus) and four preservation species of the third class (Lanius cristatus, Rhyacornis fuliginosus, Trimeresurus mucrosquamatus). 9. Aquatic species: There are mostly common fishes of western slope river and there is no dominate species. However, there is one preservation species of the third class, Sinogastromyzon puliensis. This project has analyzed and predicted possible environmental impacts based on items and quantities of anticipated construction activities for both construction and operation periods. The analyzed results indicate that TSP might be increased by excavation, transportation activities and use of large number of machineries. TSP and NOX in the air may exceed air quality standards due to lack of protection measures, poor construction management and weather conditions in winter and spring seasons. Construction machineries and transportation of construction dirt should use flood control construction access roads as much as possible to minimize the negative impacts of noise and vibration to the adjacent villages and to maintain traffic service level at A~B class. As for operation period, activities are mainly low influences to water quality, thus there will be slight impact to air quality, noise and vibration, and traffic flow. Upon completion, the man-made lake will provide a scenic and recreational lake for Cao-Tun township. Mitigation measures for negative impacts during construction period for air quality, noise and vibration, water quality, treatment of excavated dirt and waste materials are as follows: 1. Air qulity i. Follow the regulations of “ management of Air Quality Control Facilities for Construction Activities” to control air pollution. ii. Iustallation of sign, and feuse for the construction site. iii. Cover the soil pile by dust prevention textiles or net; cover exposed areas without construction activities within a week; limit construction area of all sites to be within 5 ha. iv. Pave the access road to reduce dust. v. Provide control measures for bare ground according to regulations. vi. Transportation vehicles should be washed prior to leaving construction site and should be covered with dust prevention textiles. vii. Vehicles should be parked at the area north of the construction site along the flood control access of Wu River, and engine should be stopped to reduce impacts to environmental sensitive sites. viii. Attentions should be paid to changes of monitoring values during spring and winter seasons to avoid large area construction under poor weather condition. ix. Calculate carbon emission, adopt green materials and green energy approaches, and utilize environmental friendly strategies to mitigate carbon emission in detailed design phase. 2. Noise and vibration i. Use machineries with low noise and vibration, and provide maintenance periodically. ii. Avoid to have too many machineries working at the same construction area at the same time. iii. Reduce vehicle speed down to less than 30 km/hr in the area adjacent to noise sensitive site and avoid to use horn. iv. Construction materials should be transported during day time and avoid construction activities in night time. v. Install fences around the construction site boundary, and install temporary sound proof wall next to machineries having high nosie. 3. Water pollution i. Prepare a “Waste Water Pollution Reduction Plan” prior to construction for the approval of client to be followed during construction period.3 ii. Well planned the construction methods for weir and the man-made lake, treatment facilities and measures for surface runoff drainage system, soil erosion and waste water generated by workers (including operation period ). iii. The constructor should provide all necessary temporary soil and water conservation facilities, all activities that may cause pollution to surface water are prohibited. iv. Provide collection ditch upstream of the construction site and surface water drainage system downstream of the construction site according to regulations. Surface runoff from the constructions site should be settled prior to release out of the constructions site. v. The weir will be constructed using “Half River Flowing Method “ to avoid the increase of turbidity in river. vi. Temporary lavatories should be provide at office , dormitories and construction sites. 4. Transportation i. Vehicles with excavated soil should transported in specific routes, transporting excavated soil through residential areas are prohibited. ii. The constructor should provide detailed construction plan, traffic maintaining plan and environmental protection plan during construction. iii. Access to the construction site should have traffic directions persons, traffic signs and lines should be installed. iv. Traffic control station should be provided at access to the construction site to inspect loading, covering and cleaning of vehicles. 5. Maintenance of ecological environments i. Use “Half River Flowing Method” for weir constructions to maintain hydraulically conditions. ii. The ecological base flow of 8.18 cms (exceed probability of 95%) should be maintained in the river. Continue on habitat restoration for the index species Sinogastromyzon puliensis. iii. Fish way should be provided at the weir to conserve the aquatic species in this river reach. There will be two fishway constructed including a nature-like fishway and a water fall type fishway. The design of fishway will consider the behavior of Sinogastromyzon puliensis. iv. Spread water at bare ground and along traffic route, and cover the stock pile to reduce the influence of vegetation growth by dust. v. Install fences to reduce noise, dust and man-made disturbance. vi. Create an ecological corridor by vegetation, forest belt, man-made wet lands coupling with the new drain ditch and the man-made lake for ecological compensations. In addition to all mitigation measures mentioned above, this project has also complete the “Environmental Monitoring Program Prior to construction”, “Environmental Monitoring Program during Construction Period” and “Environmental Monitoring Program during Operational Period” to understand environmental qualities of each stage of the project to evaluate the effectiveness of environmental protection measures or to modify construction plan and operation strategies.