TABLE 5. COMPARISON OF KEY ALTERNATIVE ACTIONS KEY COMPONENTS ALTERNATIVE 1: NO ACTION: ALTERNATIVE 2: MODIFIED PROPOSED ACTION ALTERNATIVE 3: NO WATER STORAGE These systems are required by law to maintain a minimum 10% flow, but no monitoring information is available. Option C: Same as Alternative 2 Water Conveyance (to Storage and to fields) Not specified. Scoping indicates a wide-variety of conveyance systems would continue to be used. Open channel canals or closed pipe using appropriate materials for the designed application from source to storage may be used depending on site- specific conditions. Open systems would generally be less than 100 meters in length and would be cement lined to reduce infiltration and facilitate maintenance. Only closed systems using appropriate pipe material are used to convey water to fields to maintain pressure for drip irrigation. Direct closed system piping to fields using the most appropriate materials for the designed application. Storage Type Not specified. Scoping indicates earthen storage types are the most common type except for very small applications where cement tanks have been used. Earthen dams. Storage in Metal, Cement or Plastic Tanks. These may be either above or below ground. Storage capacity limited by tank size and cost which can be modified by the number of tanks. These systems would generally only be practical for individual family applications. No storage. Storage Size Storage size is only limited by site-specific physical conditions, water availability, developer objectives and ability to comply with Honduran environmental laws. Scoping indicates that system sizes can generally be grouped into three categories. 1) micro storage that generally only serves individual family uses; 2) small storage with embankments less than six meters in height and Specific storage size is limited by site-specific physical conditions, water availability, ability to comply with all PEA design criteria and implementing partner objectives. As a general rule, reservoir size should be limited to dam heights less than six meters at the downstream toe and provide water storage of approximately 10,000 to 20,000 m3. Based on site-specific conditions these could also be designed No storage
TABLE 5. COMPARISON OF KEY ALTERNATIVE ACTIONS KEY COMPONENTS ALTERNATIVE 1: NO ACTION: ALTERNATIVE 2: MODIFIED PROPOSED ACTION ALTERNATIVE 3: NO WATER STORAGE storage capacities less than 15,000 m3 and serving small groups of less than 15 farmers; and 3) large systems with dam heights greater than 6 meters and capacities of up to 80,000 m3 that serve as many as 80 farmers. in a series of smaller reservoirs to increase overall capacity. Tank storage size is limited by costs and capacity of each tank. Multiple tanks may be used to increase available water volume. Storage Location Not specified. Scoping indicates existing systems occur both within natural rainwater collection basins and outside of stream channels. Earthen storage could occur within natural basin collection areas, or outside of permanent stream channels. No dams would be constructed directly within permanent stream channels. Tanks could be located anywhere based on topography. No storage System Access Not specified. Scoping indicates that system access is driven by location and size. Systems located near areas currently being farmed and designed for small applications generally require less road construction for access. Larger systems using heavy equipment require larger and more permanent road access. Only temporary access roads needed for construction access of small equipment would be allowed. Access routes would be restored to preconstruction conditions following use. Only temporary access roads needed for construction access of small equipment would be allowed. Access routes would be restored to preconstruction conditions following use. Irrigation System Not specified. Scoping indicates a variety of systems including flood, sprinkler and drip would continue to be used. Gravity fed drip system. Gravity fed drip system. Crop Management Not specified. Scoping indicates a wide range of crops and crop management practices would continue to be used. Larger projects currently being planned and implemented are generally limited to 10 hectares of cropland to comply with Honduran environmental law. However the number of participants can vary from single user systems Groups of approximately 10- 15 participants would cultivate approximately 10 hectares of cropland. Technical assistance provided to help producers learn to cultivate higher value crops to increase crop diversity and incomes. Technical assistance provided to improve efficient water use and incorporate Climate Smart agriculture practices such as Same as Alternative 2.
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY 3. Site selection should utilize the Agri-Tool software developed through USAID and CIAT to help identify and evaluate all possible options for site location. Program Manager Agri-tool output Existing agency personnel are trained in the use of the tool, and staff engineers can use Agri-tool watershed delineations, slope information, etc., to build Hydrologic models; When: Planning and Design. Initial site selection phase 4. Identify and integrate the spatial aspect and relationship of all users in a drainage system including the size and locations of other reservoirs on those tributaries, and the water rights within the system. DOR/Project Manager Map of water uses occurring in the affected watershed, Includes water volume (m3) for each use. During the planning phase, identify through community interviews, available information other activities and land uses in the affected watershed that could influence available water or be affected by the proposed project. Information is incorporated in design specifications and used by the project manager to resolve potential conflicts with other activities. During initial site selection phase 5. Ensure design and construction includes a review of the design for technical accuracy by a competent professional and verification of construction quality and adherence to the plans and specifications. DOR/Project Manager # Designs reviewed Date of Review Review Design Prior to construction 6. Obtain all required permits and approvals prior to beginning construction. DOR/Project Manager Permit List Consult local municipality, MiAmbiente, and local water board. Prior to construction 7. Ensure adequate access can be achieved using only existing or temporary roads and that temporary roads are obliterated following use DOR/Project Manager # meters temporary roads # meters existing roads Based on equipment needs, ensure existing roads are adequate for construction equipment. Where temporary roads are used they must be obliterated and restored to pre-construction conditions following use Prior to construction
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY 5. The dam should be located to minimize height of earth embankment while achieving required storage and pressure to the irrigation system. No embankment should be greater than 6 m. high. DOR Completed Design calculations Narrative in design memorandum explaining the optimization of embankment location and height to provide the required storage capacity and pressure. In cases where the embankment is greater than six meters high, a special justification and technical specification must be included in the design. As a general rule, embankments taller than 6 meters present more risk of failure due to seepage and piping. (Design Phase ) Design and construction phase 6. Embankment Side slopes should be at a minimum 3H:1V. DOR and Construction Contractor Side slope measurements Site plans and specifications should clearly show the side slopes of the embankment (DOR). Side slopes of embankment should be checked during construction for conformance with plans and specifications documents. Design phase and construction phase 7. Alignment/locations of the embankment features should be laid out on the ground in the field before construction begins. Wooden stakes are recommended and may be color coded. DOR, Construction Contractor, Farmers Dates of preconstruction field layout Meet on site and lay out the embankment alignment before construction begins. The layout at a minimum should include the crest of the embankment (where it ties into high ground), upstream and downstream toe, spillway, and excavation outline of reservoir. Construction Phase 8. No excavation activities of the reservoir shall be closer than 10 meters to the upstream toe of the embankment. See figure 19 of Tech Guide DOR and Construction Contractor Completed Design Show excavation limits on plans and specifications and ensure direction is clear. (DOR). Ensure compliance with plans and specifications during construction (CC). Design and construction Phase 9. All the vegetation, rocks and loose soil shall be removed from the footprint of the embankment (clearing and grubbing). DOR and CC % vegetation, rocks and loose soil on embankment Show clearing and grubbing excavation section and detail on plans and ensure direction is clear in specifications (DOR). Ensure compliance with plans and specifications during construction (CC). Design and construction
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY Engineering and Construction Reservoir Location 1. Only use in-line storage when off-line storage is not available or feasible. In-line storage presents greater risk of failure Program Manager Decision rationale documented in initial planning report. Document rationale for reservoir location in design report. Design Phase Engineering and Construction Tank Storage System 1. Tank storage may be considered only if an earthen reservoir is not feasible. Due to high cost, this option is generally limited where water needs are small (<1,000 m3). Program Manger Decision rationale documented in initial planning report. Document rationale for storage type in design report. Design Phase Engineering and Construction Conveyance to Field 1. Assure pressure requirements (minimum and maximum) are provided by the conveyance system for the proposed irrigation system. DOR Volume and psi. Provide irrigation conveyance calculations that show flow and pressure through the system. Pressure reducers/regulators are included where needed. Show pressure does not exceed recommended values of pipe system. Design Phase Water Flow
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY 1. Identify and integrate the spatial aspect and relationship of all users in a drainage system including the size and locations of other reservoirs on those tributaries, and the water rights within the system. DOR/Project Manager Number and type of other water uses in watershed Identify through community interviews, available information other activities and land uses in the affected watershed that could influence available water or be affected by the proposed project. Information is incorporated in design specifications and used by the project manager to resolve potential conflicts with other activities. Planning Phase 2. For Alternative 2 (Option B, and C and Alternative 3, monitor and maintain ecological flows Project Manager Flow volume (m3/hour) Utilize the guidance in USAID Best Management Practices for Small Hydroelectric Projects (USAID 2012) Monthly 3. Measure NNIS as indicators of stream health for systems utilizing springs (Alternative 2 Option) and Alternative 3. Project Manager # occurrences #species Where land ownership patterns permit, establish five permanent two-meter diameter plots within 100 meters of water diversion. Prior to construction and Annually during growing season 4. To assure that only water for peak flow is collected; the mean flow shall be estimated using either the rational formula with intensity equivalent to one year period, or by duplicating the ecological flow defined on the hydroelectrical ecological flow guide. DOR Flow volume (m3/hour) This will allow the weir to be calibrated to collect only water above the mean flow. Optional diversion methods would include either a standard diversion weir with pipes at the bottom to allow water to pass up to the ecological flow, or at the base of the natural channel define the height of the water surface for the ecological discharge and construct a lateral weir that allows withdraw of water only above that level. Design phase
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY 5. Withdraw water from the spring within authorized limits only. In case of severe drought, or if riparian condition monitoring (NNIS frequency) indicates measurable changes from baseline, the flows should be rerouted back to the natural system. Project manager Flow volume (m3/hour) Monitor flow volumes Monthly 6. Monitor and track water usage for each system. Farmers Water volume used (m3/day) Based on the storage volume of the reservoir, maintain a daily record of water levels and use. Compare annual use with other systems in the watershed to track potential cumulative effects. Daily 7. Develop and institute a Monitoring and Information System capable of collecting information on water flows and use throughout each watershed. SAG and DGRH Volume of water stored by watershed/Volume of surface water available for watershed (%) This system would incorporate geo-referenced flow information for tracking all water use in each watershed. Data collected monthly and summarized annually. Planning phase. Water Quality 1. Use only pesticides listed in the most recently approved Honduras PERSUAP Participants List of pesticides used Complete a list of agrochemicals used. Each crop cycle 2. Follow application methods and protocols described in the most recently approved Honduras PERSUAP Participants Quantity and method of application used Complete a list of agrochemical application rates and methods used. Each crop cycle
MITIGATION MEASURES FOR THE PROPOSED ACTION DESCRIPTION OF MITIGATION MEASURE RESPONSIBLE PARTY INDICATORS METHODS FREQUENCY Reservoir Nuisances 1. The entire reservoir shall be fenced with at least 3-strand barbed wire or other effect materials to exclude cattle from grazing on any portion of the interior or exterior banks. Group Participants # of fences Fence is closed at all times Visual inspection that fence is constructed immediately following excavation. Visual inspection of fence daily. Prior to and during operation 2. Technical assistance will include a provision to make the participants aware of potential wildlife concerns and promote community awareness of the need to protect wildlife that use the reservoirs. Group Participants # of participants receiving technical assistance Inclusion of wildlife awareness during technical assistance training. Prior to and during operation Community and User Conflicts 1. Design construction and operation must comply with Honduran laws which include appropriate land tenure and rights-of-way be established. Promoter and Participating User Group Documentation of completed tenure approvals. Participating group with promoter assistance to obtain and document legal compliance. Prior to project development Site selection phase 2. Pre development community involvement is conducted to educate the potentially affected individuals and develop clear consensus related to participation. Promoter # of consensus building meetings conducted Project promoter conducts meetings with local communities and governments Prior to project development Site selection phase