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HomeMy WebLinkAboutA001 - Letter dated December 18, 2006 from Department of Natural Resources Fields of Opportunities STATE OF I O WA THOMAS J. VILSACK, GOVERNOR DEPARTMENT OF NATURAL RESOURCES SALLY J. PEDERSON, LT. GOVERNOR JEFFREY R.VONK, DIRECTOR December 18,2006 City of Ames Mr.Tracy Warner,Municipal Engineer 515 Clark Avenue Ames,IA 50010 Dear Mr. Warner: After reviewing your request for State 401 Water Quality Certification, the Iowa Department of Natural Resources has issued the enclosed Certification. Please read the attached conditions carefully before beginning work on the project. A copy of this Certification has been forwarded to the office of the Army Corps of Engineers as indicated below. You are advised to contact that office upon receipt of this certification. If you have any questions or comments about the certification or any conditions contained therein, please contact me at the address shown below or call (515) 281-6615. Sincerely, Christine M. Schwake Environmental Specialist cc: Mr.John Betker,Department of the Army Corps of Engineers,Rock Island District,Clock Tower Building,P.O. Box 2004,Rock Island,IL 61204-2004 Mr. Doug Ernst,Engineering Alliance,Inc.,8191 Birchwood Court,Suite L,Johnston,IA 50131 Ms. Eva Moritz,Terracon Consultants,Inc.,600 Southwest 7th Street,Suite M,Des Moines,IA 50309 WALLACE STATE OFFICE BUILDING/DES MOINES,IOWA 50319 515-281-5918 TDD 515-242-5967 FAX 515-281-6794 WWW.STATE.IA.US/DNR IOWA DEPARTMENT OF NATURAL RESOURCES SECTION 401 WATER QUALM CERTIFICATION Certification issued to: Effective: December 18,2006 City of Ames, 515 Clark Avenue,Ames,IA 50010 Project certified: US Army Corps of Engineers,joint Public Notice No.CEMVR-OD-P-2006-1050 State 401 Water Quality Certification,Application Log No.: 06-K-169-1 1-04-S Proposal to widen and pave approximately 5400' of Southeast 16th Street between South Duff Avenue and South Dayton Avenue and replace an existing bridge crossing the Skunk River in S 11-14,T83N,R24 W,Story County. A pedestrian trail will be constructed along the roadway alignment. The bridge and roadway will impact approximately 1.01 acres of primarily forested wetland. To mitigate for wetland impacts, approximately 1.52 acres of wetland and 0.5 acre of upland buffer will be created onsite. Water quality use designation: The South Skunk River is designated as a Class A 1 Primary contact recreational use. These are waters in which recreational or other uses may result in prolonged and direct contact with the water, involving considerable risk of ingesting water in quantities sufficient to pose a health hazard. Such activities would include,but not be limited to,swimming,diving,water skiing,and water contact recreational canoeing. The Skunk River is also designated as a warm water Type 2 Class B(WW-2). These are waters in which flow or other physical characteristics are capable of supporting a residential aquatic community that includes a variety of native nongame fish and invertebrate species. The flow and other physical characteristics limit the maintenance of warm water game fish populations. The waters generally consist of small perennially flowing streams. The impacted wetlands are designated as General Use Water and are protected at all places at all times for livestock and wildlife water, aquatic life, non-contact recreation, crop irrigation, and industrial, domestic,agricultural,and other incidental water withdrawal uses. The Iowa Department of Natural Resources (IDNR) has issued this State 401 Water Quality Certification pursuant to Section 401 of the Clean Water Act. The Army Corps of Engineers (Corps) requires state Certification before a Section 404 permit can be issued. Section 401 Certification represents the IDNR's concurrence that the project certified is consistent with the Water Quality Standards of the state of Iowa as set forth in Chapter 61,Iowa Administrative Code. Subject to the attached conditions,incorporated by reference herein,the IDNR has determined that there is reasonable assurance the proposed activities will be conducted in a manner that will not violate water quality standards of the state of Iowa. Prepared By: (y � 5 � Date Executed: December 18,2006 Christine M.Schwake,IDNR,Wallace State Office Building,Des Moines,IA 50319-0034 (515) 281-6615 STATE OF IOWA COUNTY OF POLK I HEARBY CERTIFY I AM THE OFFICIAL AND LAWFUL CUSTODIAN OF THE PUBLIC RECORDS MAWTAINED BY THE IOWA DEPARTMENT OF NATURAL RESOURCES AND THE FOREGOING DOCUMENT IS A TRUE AND ACCURATE PHOTOCOPY OF THE RECORD COPY MAINTAINED IN MY CUSTODY AS A PUBLIC RECORD OF THE DEPARTMENT W THE ORDINARY COURSE OF ITS BUSINESS. EXECUTED AT DES MOINES ON 14.4 6 GENERAL CONDITIONS 1. Permittee is responsible for securing and for compliance with such other permits or approvals as may be required by the IDNR, federal, state, or local governmental agencies for the project activities described. 2. You are encouraged to conduct your construction activities during a period of low flow. 3. Clearing of vegetation, including trees located in or immediately adjacent to waters of the state, shall be limited to that which is absolutely necessary for construction of the project. All vegetative clearing material shall be removed to an upland,non-wetland disposal site. 4. All construction debris shall be disposed of on land in such a manner that it cannot enter a waterway or wetland. Construction equipment, activities, and materials shall be kept out of the water to the maximum extent possible. Equipment for handling and conveying materials during construction shall be operated to prevent dumping or spilling the material into waterbodies, streams or wetlands except as approved herein. Care shall be taken to prevent any petroleum products, chemicals, or other deleterious materials from entering waterbodies,streams or wetlands. S. Erosion control features (i.e., silt fences, silt ditches, silt dikes, silt basins, etc.) must be installed to provide continuous erosion control throughout the construction and post construction period as well as the revegetation of all disturbed areas upon project completion. Where siltation control features have been reduced in capacity by 50% or more, the features shall be restored to their original condition with a minimum of delay. 6. All disturbed areas not covered with riprap shall be seeded with native grasses, excluding Reed Canarygrass (Phalaris arundinacea) or any aggressive or invasive species, during an optimal seeding period. If excavation and construction are completed outside an optimal seeding period, temporary erosion control protection shall be implemented immediately upon completion of excavation and construction and shall be maintained until such time as seeding can be completed during an optimal period. The applicant shall monitor revegetated areas continuously to assure success of revegetation. If rye is initially planted to stabilize the soil then native warm season grasses shall be planted during the following growing season. 7. If te mporary crossings are needed for the project,then the temporary structures and f'p J � p ry r11s shall involve the least damaging and minimu m amount of disturbance/ impacts cts to waters of the state and d appropriate measures must be taken to maintain near normal downstream flows,allow the passage of fish, and minimize flooding. Fills shall be constructed of clean aggregate of suitable size to prevent washing out of the structure by high flows. All temporary fills shall be completely removed to an upland, nonwetland site and the area restored to pre-project conditions within 30 days of the end of their use. 8. Flowable mortar shall be kept out of the stream. 9. The removal of the old bridge structure will include the piers and the removal will be in conformance with all applicable state and local requirements. The old bridge and its piers will be removed to at least one foot below the natural river bed. 10.Any debris from the bridge removal that falls into the water will remain there only temporarily and will be removed accordingly. The debris will be properly disposed of in an upland,non-wetland location. 11.Acceptable revetment material includes clean: riprap, field stone, quarry rock, and broken Portland Cement Concrete (PCC). When using broken PCC,all exposed reinforcing steel rod or mesh must be completely removed from it; if removal is not possible, the reinforcement material shall be cut flush with the surface of the concrete prior to placement. It shall be the applicant's responsibility to maintain the riprap such that any reinforcement material that becomes exposed in the future is removed. Any concrete pieces larger than three feet in average diameter must be broken into smaller pieces prior to placement. The revetment shall consist of a uniform mixture of sizes of material laid to form a compact surface capable of resisting erosion. The use of asphalt or other solid waste is prohibited. The horizontal thickness of the revetment shall not exceed four feet. The finished slope on the revetment shall be no steeper than two feet horizontal to one foot vertical (2H:1 V). MITIGATION CONDITIONS 1. Mitigation shall be completed within one year from the date that the first fill is placed in any wetland. An as-built plan shall be submitted to the IDNR and to the Corps upon completion. The 1.52-acre replacement wetland shall be monitored annually and managed to confirm whether it has successfully replaced the function and values of the impacted wetlands after a five-year period. If,at the end of the fifth year, the expected water level is not achieved, more than 50 percent of the emergent vegetation are non-native species,tree survival,by species,is less than the 80 percent, or if evidence exists that the replacement wetland is becoming less effective, then additional monitoring and/or corrective actions shall be taken to achieve the compensation ratio as originally approved. Annual monitoring reports shall be submitted to the IDNR and to the Corps'office by December 31 for at least five years following planting. 2. By the end of September of each year the tree plantings will be reviewed. Seedlings shall be replanted as necessary to ensure an 80%survival rate by species. 3. Future development or land-use conversion of the wetland mitigation area,or any part thereof, for any purpose that may interfere with or be detrimental to wetland functions, is prohibited without prior written approval from the IDNR and the Corps. Prior to commencement of project construction the applicant shall, with the knowledge and approval of the property owner of record, file a copy of this certification in its entirety with the County Recorder for entry into the property records,thereby notifying all parties of this restriction. Further, prior to commencement of construction, said applicant shall provide the IDNR and the Corps with a "Filed" stamped copy of this certification. If the certification cannot be filed in the manner indicated, the applicant shall provide the IDNR with documentation of agreements, contracts, etc., demonstrating to the IDNR's satisfaction that the wetland mitigation site will be protected from future activities that may interfere with or be detrimental to wetland functions and values to a level of assurance equivalent to that provided by the aforementioned filing process. 4. The mitigation concept proposed in the joint application form prepared by Terracon (October 18, 2006) shall be followed when constructing the mitigation sites. The City will create/restore 1.52 acres of wetland and 0.5 acre of upland buffer to compensate for the impacts to 1.01 acres of primarily forested wetland. The City of Ames shall assume all liability for accomplishing any needed corrective work. Corrective work will be required if 1.52 acres of wetland not develop as wetland (according to the '87 Manual) or if the Corps determines that the mitigation site is not developing satisfactorily. Remedial work may include grading and/or planting the mitigation site, or may require a new mitigation site. 5. The annual site surveys of the mitigation site shall assess the vegetation, hydrology, and soils. The results of each survey will be documented in an annual monitoring report. Annual monitoring reports shall be submitted to the IDNR and to the Corps by December 31 for at least five years following planting. The reports must include photos, a vegetative cover map indicating dominant species in each area, an assessment of wetland hydrology according to the 1987 Corps of Engineers Wetland Delineation Manual ('87 Manual), a map with drawn boundaries indicating exactly what areas are wetland according to the '87 Manual,and any corrective actions taken or needed. All maps must be to scale and have the scale plainly labeled. WETLAND MITIGATION PLAN SE 161h Street Paving & Bridge Replacement Project SE 16th Street fro m Duff to Dayton Avenue Ames, Iowa Terracon Project No. 08067012 USACE No. CEMVR-OD-P-2006-1050 October 18, 2006 1.0 INTRODUCTION Terracon was retained by the City of Ames and Engineering Alliance, Inc. to develop a mitigation plan for the SE 16th Street paving and bridge replacement project in Ames, Iowa. J The subject site is located in portions of Sections 11, 12, 13 and 14, Township 83 North, Range 24 West, Story County, Iowa as depicted on Figure 1 in Appendix A. Terracon performed a wetland delineation for the proposed ;project and identified thirteen (� wetland areas. The locations of the wetlands can be seen on Figure 2 in Appendix A. We identified 1.324 acres of wetlands, of which 1.01 acres will be impacted by the project. Please note that following submittal of the delineation report, wetland areas WL-4 and WL-6 were j extended north based on updated project boundary information. One Water of the United States (WUS), the Skunk River, was identified within the project area. 1 The locations of the WUS can be seen on Figure 1 in Appendix A. The project will include replacement of the bridge across the Skunk River, as shown on Figure 3 (Sheet 3) in Appendix t A. i i 2.0 UNAVOIDABLE IMPACT DISCUSSION The City of Ames is in the process of implementing long-range plans for street improvements. The plans include paving approximately 5,400 feet of SE 161h Street between South Duff Avenue and South Dayton Avenue. The project area can be seen on Figure 2 in Appendix A. The street project is vital for the future growth of the City and the paving is necessary for safety purposes and to handle increased traffic in the area. The City will be paving the existing gravel road and providing two traffic lanes. A pedestrian trail and canoe access/parking area will also be installed along the alignment. The centerline of the proposed alignment will coincide with the existing road alignment to minimize impacts to surrounding property owners. The pedestrian trial will be located on the north side of the road. A secondary purpose of the roadway and bridge improvements is to lessen the effects of flooding on SE 16th Street. The Skunk River has flooded the existing road/bridge approximately five times since 1993. The current roadway and bridge were designed to withstand a 10 to 20 Wetland Mitigation Plan Terracon Consultants;Inc. -` Aff SE 16�n Street Ames, Iowa ' Terracon Project No. 08067012 ' October 18, 2006 year storm event. The proposed roadway will remain above water following a 50 year storm event and the new bridge will withstand a 100-year storm event. The project will include the replacement of the existing 20-foot wide pony truss bridge with a 36- foot wide bridge. The road profile on the eastern half of the project will be raised approximately - two to five feet above the current roadway and the elevation of the proposed bridge will be approximately five feet above the elevation of the existing bridge. Wing walls will be installed at the bridge to divert flood water beneath .the bridge to minimize the effects of flooding. The channel of the Skunk River near the bridge will be widened to reduce the effects of flooding to SE 16"' Street and to improve hydraulics of the bridge. The proposed SE 16°i Street paving and bridge replacement project is necessary to support future growth of the City as well as to provide additional protection and safety against future flood events. 3.0 IMPACTED JURISDICTIONAL WETLANDS Terracon identified thirteen wetlands within the project area. Of the 1.324 acres identified at the site, 0.314 acres would be considered isolated by the U.S. Army Corps of Engineers (USACE). The following wetlands are considered isolated roadside ditch wetlands WL-1,- WL-2, WL-3, portions of WL-4, WL-5, WL-7, WL-8, portions of WL-9, WL-10, WL-11, WL-12, and WL-13. Wetland WL-6 and the portions of WL-4 and WL-9 adjacent to the Skunk River would be considered jurisdictional. Please note that following submittal of the delineation report, wetland areas WL-4 and WL-6 were extended north based on updated project boundary information. _ The proposed trail will impact 1.01 acres of jurisdictional wetland. The following sections address the jurisdictional wetland on the project site. Details concerning the amount of delineated and impacted wetlands can be seen on Table 1 in Appendix B. 3.1 Wetland Area 4 Wetland Area 4 (WL-4) is located north of S `n E 16 Street in the central portion of the site. The �- wetland delineation report identified 0.387 acres at WL-4; however following submittal of the delineation report, the boundary of WL-4 was extended north based on updated project information. The western portion of WL-4 (0.06 acres) is located in a within a roadside ditch i and would be considered isolated. The jurisdictional wetland along the Skunk River covers I approximately 0.52 acres; however the wetland appears to extend throughout the forested bottomland along the river and only the area in the vicinity of the project was delineated. The lisolated and jurisdictional wetland areas are depicted on Figure 2 in Appendix A. Approximately 0.52 acres of jurisdictional wetlands will be impacted by the project. L 2 Wetland Mitigation Plan Terracon Consultants, Inc. rr SE 161h Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 The dominant wetland species present included sedge species, reed canary P silver maple, bedstraw and wild violet. The jurisdictional portion of grass, green ash, be considered forested. It appears that the wetland is receiving hydrology from surface water wetland drun- off and the Skunk River. The soil characteristics appear to be similar to Coland clay loam, which is listed on the Story Count and national Y hydric soil lists. 3•2 Wetland Area 6 Wetland Area 6 (WL-6) is located north of SE 161h Street in the central portion of the site. The _ wetland delineation report identified 0.358 acres at WL-6; however, the boundary undary of WL-6 was extended north based on updatedon. Skunk River in the project area covers approximately 0.44 acres; however atlhe wetly along the to extend throughout the forested bottomla wetland appears nd along the river and only the area in the vicinity of ' the project was delineated. The wetland area is depicted on Figure 2 in Appendix A. ` Approximately 0.44 acres of jurisdictional wetlands will be impacted by the project. The dominant wetland species present included sedge species, reed canary grass, stinging nettles, green ash, wood nettle, wild violet, bedstraw and silky dogwood. This area would be - considered a forested wetland. It appears that the wetland is receiving hydrology from surface water run-off. The soil characteristics appear to be similar to Coland clay loam, which is listed on the Story County and national hydric soil lists. 3.3 Wetland Area 9 � I t Wetland Area 9 (WL-9) is located south of SE 16h wetland delineation report identified 0.128 acres at WL-9. The'easter Street in the central portion of t_he site. The n portion of WL-9 (0.078 acres) is located in a within a roadside ditch and would be considered isolated. The jurisdictional wetland along the Skunk River covers approximately 0.05 acres. The isolated and jurisdictional wetland areas are depicted on Figure � p 2 in Appendix A. Approximately 0.05 acres of jurisdictional wetlands will be impacted by the project. The dominant wetland species present included sedge species, reed canary grass, green ash stinging nettles, cattail, and silky dogwood. This area would be considered a wet meadow wetland with minor tree growth. It appears that the wetland is receiving hydrology from water run-off and the Skunk River. The soil characteristics appear to be similar g to Coland clay loam, which is listed on the Story County and national hydric soil lists. i 3 w , Wetland Mitigation Plan Terracon Consultants, Ind. SE 161"Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 4.0 IMPACTED WATERS OF THE UNITED STATES The Skunk River was identified on the USGS Topographic Map (Figure 1 in Appendix A '• PP ) and would be considered a Water of the United States. A proposed bridge will impact.the Skunk River at one location. Construction plans for the proposed bridge can be seen as Figure 3 (Sheet 3) in Appendix A. I The proposed bridge will be 36 feet wider, will span 304 feet between abutments, and will have two supporting piers within the Skunk River. The existing 20 foot wide, 273 foot long pony truss bridge and two associated piers will be removed as part of the project: .The banks of the Skunk River on either side of the bridge will be reshaped to improve the hydraulics of the river at the T bridge. Rip rap will be installed along portion of the re-graded channel. The new grading will create a 170-foot wide channel bottom. Wing walls will be constructed on either side of the bridge abutments to provide additional flood protection for the roadway and bridge. Details regarding the wing walls can be seen on Figure 3 (Sheet 3) in Appendix A. Wetlands WL-4, WL-6 and WL-9 were identified adjacent to the Skunk River near the proposed bridge. .I. 5.0 FUNCTIONS AND VALUES OF THE JURISDICTIONAL WETLAND The functions and values for the jurisdictional wetland are based on the "The HiQhway Methodology Workbook Supplement: Wetland Functions and Values" 1995 The methodology evaluates wetland functions and values from a descriptive approach. A jurisdictional wetland may have the following functions and values: groundwater recharge/discharge, • flood flow alteration, • nutrient removaVretention/transformation, • production export, • sediment/shoreline stabilization, • wildlife habitat, • recreation, • educational/scientific value, • uniqueness/heritage, • visual quality/aesthetics, and/or • endangered species habitat. The principal functions of the jurisdictional wetlands for the proposed project are groundwater recharge/discharge, flood flow alteration, nutrient removal/retention/transformation, sediment 4 Wetland Mitigation Plan Terracon Consultants, Inc. SE 161h Street Ames, Iowa Terracon Project No. 08067012 October 18,2006 stabilizatio n, and wildlife habitat. The wetlands consist of wetland herbaceous and forested N species primarily along the river. 6.0 PROPOSE® MITIGATION SITE Engineering Alliance, Inc. and the City of Ames have chosen to create an on-site mitigation area adjacent to the Skunk River north of SE 161h Street to offset the wetland impacts. The mitigation site is located directly west of WL-4, as shown-on Figure 2 in Appendix A. The Mitigation site is located within a 2.2-acre property that will be purchased by the.City.. Terracon designed a 1.52 acre wetland mitigation area that will consist of forested wet mead ow and emergent wetlands between the elevations of 52 and 55 feet. Approximately 0.5 acres of buffer will be planted around the mitigation site. Surface water runoff from surrounding upland 4. areas will support the mitigation site. A mitigation ratio of g . approximately 1.5 to 1 was selected based on the quality and diversity of the delineated wetlands and the use of an adjacent mitigation site. The planting plan for the mitigation area will result in higher quality wetlands with more diverse tree and plant species. The mitigation plan will include tree and shrub plantings for impacts to forested wetlands. Additional details regarding tree plantings can be found in Section 10.2 of this report. The "Soil Survey of Story County Iowa" identified Spillville loam and Coland clayloam soils in the vicinity of the wetland mitigation area. Both soil types of were identified on the Story County hydric soil list and Coland soils are included on the national hydric soil list. These soils will provide appropriate conditions for supporting the mitigated wetlands. 7.0 HABITAT/BUFFER AREA In addition to the 1.52 acres of wetland mitigation, approximately 0.5 acres of buffer will be planted around the mitigation site. The buffer will be planted with a wildflower and grass seed mix, as described in Section 10.3 of this report. The buffer area will reduce water qualityimpacts to the mitigation p igation area and will enhance the water quality within the site. The buffer will retain soil eroded from the upland ground and will minimize siltation of the mitigated wetlands. 8.0 GOALS FOR THE MITIGATION SITE The delineated wetlands are located in a forested bottomland adjacent to the Skunk River. The City will be creating a wetland mitigation area directly upgradient from the impacted wetlands. 5 Wetland Mitigation Plan Terracon Consultants, Inc. SE 16"' Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 The mitigation area was designed to have similar functions as the existing wetlands and they will provide the opportunity to increase the variety and quality of the wetland vegetation. The mitigated wetland and surrounding buffer area will have functions including the following: • Groundwater Recharge/Discharge: This function refers to the interaction between the wetland and aquifer. The wetland mitigation area will provide enhanced functions for groundwater recharge/discharge because it has been designed to contain overland flow of surface water. The.water retained in the wetlands will slowly infiltrate through the base of the wetland and be discharged into the aquifer and to the adjacent Skunk River. • Flood Flow Alteration: This function considers the effectiveness of the wetland Jn reducing flood damage by water retention for prolonged periods following precipitation events and the gradual release of floodwaters. The wetland will provide storage capacity for surface water during periods of heavy precipitation and flood events, releasing the water slowly through infiltration. • Nutrient RemovaVRetention/Transformation: This function considers the effectiveness of the wetland as a trap for nutrients in runoff water from surrounding uplands or contiguous wetlands, and the ability of the wetland to process these nutrients into other forms. One aspect of this function is to prevent ill effects of nutrients from entering aquifers or surface waters. The mitigation area and adjacent buffer will help purify water by processing nutrients, suspended materials, and other pollutants. Surface water will enter the wetland and the flow rates will be reduced, allowing suspended materials time to settle. Wet meadow and emergent wetland vegetation and tree growth will assist in nutrient removal and transformation. • Wildlife Habitat: This function considers the effectiveness of the wetland to provide habitat for various types and populations of animals typically associated with wetlands and the wetland edge. Wetlands provide breeding, nesting, feeding, and cover habitats for invertebrates, insects, amphibians, reptiles, birds, and mammals. Migratory birds and waterfowl use the ecosystems as food, shelter, breeding, and wintering grounds. Wetlands can also potentially provide critical habitat for Federal and State-listed threatened and endangered species. The wetland mitigation area will be adjacent to the existing forested bottomland along the Skunk River. The wetland will provide enhanced functions of wildlife habitat along the existing river corridor. Y 6 ��, r i A 7 Terrac6n Consultants, Inc. Wetland Mitigation Plan SE 16`h Street Ames, Iowa ' Terracon Project No. 08067012 October 18, 2006 9.0 IMPLE.MENTATION PLAN The objectives of the mitigation plan include creating a wetland that will have increased wetland species diversity. An outline of the specification for the creation of the mitigation site includes j grading, water control structures, hydrogeologic study, and erosion control. 9.1 Grading The construction of the wetlands will consist of grading the area to the approximate elevations shown on Figure 4 Appendix A. The wetland mitigation area will be present between the elevations of 52 and 55 feet. The wet meadow zone will exist from approximately 54 to 55 feet and.the emergent zone will exist below approximately 54 feet. The mitigation area will be graded so that hydric soils are present to a depth of at least one-foot in the mitigation area. Wetland topsoil shall be handled in a manner to avoid compaction of undisturbed soils. 9.2 Water Control Structure One 24-inch culvert will be used to regulate the water level within the mitigation area. The elevation of the culvert inlet will be set at 54 feet. The approximate location of the proposed culvert can be seen on Figure 4 in Appendix A. 9.3 Hydrologic Study A hydrologic study has been performed to evaluate if the mitigation site will have enough surface water to provide saturated soils in the upper 12 inches of the wetland mitigation area. A r water balance analysis was conducted on the site area_to evaluate the amount of percolation to the water table after wetland development. The water balance is based on the relationships between precipitation, evapotranspiration, surface runoff, and soil moisture. Averages of normal mean monthly precipitation and temperature were used. Based on the Story County soil survey data, the soils within the wetland mitigation areas have high available high water capacity (available moisture capacity). In order to present a more conservative estimate of soil moisture storage, the available moisture capacity was assumed to be in the low to moderate range. The water balance analysis indicates that approximately 2 to 6 inches of soil moisture storage will be available in the wetland mitigation .site throughout the year. The wetland should receive sufficient stormwater/groundwater runoff throughout an average year to support wetland �y conditions. It is likely that the annual precipitation, along with the estimated soil moisture storage, L 1. T Wetland Mitigation Plan Terracon Consultants, Inc. ' SE 16'h Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 will be sufficient to maintain hydrology within the proposed wetland area given the structural 1 controls of the mitigation site. 9.4 Erosion Control Measures Erosion control measures will be utilized throughout the site until vegetation becomes established. The contractor will be responsible for installation and maintenance of the erosion control measures throughout the duration of construction. 10.0 PLANTING SCHEDULE 10.1 Wetland Seeding ISeeding of the mitigation site will occur after earth moving g and shaping of the site has been completed. If longer periods of time occur between shaping and the recommended planting time, final disking and harrowing preparation of the hydric soils will not take place until just prior to planting. ISeeding will be conducted by hand or by other methods of broadcasting before the mitigation area is submerged up to the normal pool. Seed should be applied at a rate of at least 12 pounds per acre. In order to ensure an even broadcast of seed, the seed may be mixed thoroughly using ten parts of moist sand to one part seed. The seed mixture could be purchased from Ion Exchange Native Seed and Plant Nursery in Harpers Ferry, Iowa or from a fcomparable vendor. The seed should be of Iowa origin, adjoining states, or as specified. Terracon recommends that the seed mixtures be a Wet Meadow Site Mix for the wet meadow wetlands in the mitigation area and an Emergent Site Mix for the emergent wetlands. The recommended seed mixtures are listed in Appendix C. The wet meadow and emergent zones can be seen on Figure 5 in Appendix A. Approximately 0.6 acres of emergent seed and 1.0 acres of wet meadow seed should be planted in the mitigation area. The following seeding methods should be utilized in the mitigation area: • Frost Seeding (February through March) — Broadcast the seed onto the seedbed, which was prepared in the fall. Allow the freeze/thaw process to work the seeds into the ground. • Spring Seeding (April through June) — Broadcast the seed into a firm, well-prepared seedbed. Lightly rake or till the seed mix into the soil. Roll or compact the seedbed after the seeds have been raked in. Keep the area moist, but not wet over the next few weeks. 8 i Wetland Mitigation Plan Terracon Consultants, Inc. . SE 16`h Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 Fall Seeding (October through December) — Broadcast the seed onto a firm, well- prepared seedbed. Allow the freeze/thaw processes to work the se ed into the ground. l 'm As part of the as-built documentation, a copy of the seed mix tag or invoice that shows the variety, origin, and analysis of the seed will be submitted to the USACE. 10.2 Tree Planting The proposed project will impact forested wetlands, as detailed on Table 1 in Appendix B. Mitigation for forested wetland imp acts will include tree plantings at a rate of 100 trees per acre for 5 gallon pot size trees or 200 trees/acre for 2 gallon pot size trees (see Table 1 in Appendix B). Shrubs will be planted at a rate of 50 shrubs per acre. Based on the impacted acres as shown on Table 1 in Appendix A, 51 shrubs and 97 5-gallon pot size trees or 193 2-gallon pot size trees) should be planted within the mitigation area. The following species shall be planted within the wetland. Tree Species Wetland Indicator Northern Pecan (Pecan.Hickory) OBL Swamp White Oak FACW+ Pin Oak FACW American Sycamore FACW Arnold Hawthorn FACW Green Hawthorn FACW Shellbark Hickory FACW Bitternut Hickory FAC Bur Oak FAC- Hackberry FAC- Black Walnut FACU Black Cherry FACU Shrub Species Wetland Indicator Silky Dogwood FACW+ Red-osier Dogwood FACW Black Elderberry FACW- Serviceberry FAC Chokecherry FAC- Nannyberry FAC+ Wild/American Plum FACU Unless otherwise approved by the USACE, at least 6 of the 12 tree species and least 4 of the 7 shrub species should be planted. Species with a wetland indicator of OBL shall be planted P 9 I � Wetland Mitigation Plan Terracon Consultants, Me. SE 161h Street �,. Ames, Iowa fTerracon Project No.08067012 October 18, 2006 4� within the lower wet meadow elevations. Species with a wetland indicator of FACW+ and FACW shall be planted within the wet meadow or lower elevations of the buffer area. Species I. ; with a wetland indicator of FAC and FAC- shall be planted within the upper elevations of the wet meadow or within the buffer area. Species with a wetland indicator of FACU shall be planted in r the buffer area. Any trees/shrub species substituted must be pre-approved by the USACE and 4 be seed, nut, or fruit producing with a wetland indicator of OBL, FACW or FAC. 1 � We recommend that tree guards be placed around the tree trunks to protect them from wildlife ! grazing. Tree species will be planted at a minimum spacing of 25 feet. The vegetation will be kept shaded and moist during transportation and prior to planting. Planting shall not occur until after earth moving and shaping of the wetland mitigation site is completed. We recommend i that the trees/shrubs be mulched, staked/guyed, pruned, and watered in accordance with the Urban Standard Specifications. 10.3 Buffer Area Planting Approximately i 0.5 acres of buffer will be planted in the disturbed area surrounding the wetland mitigation area, as shown on Figure 5 in Appendix A. The buffer will be planted with a variety of i i non-wetland vegetation and meadow wildflowers. A recommended seed mix for the buffer Lplanting can be found in Appendix C. r ! Seed should be applied at a rate of at least 12 pounds per acre. In order to ensure an even broadcast of seed, the seed may be mixed thoroughly using ten parts of moist sand to one part seed. The seeding methods described in previous sections of this report should be utilized for �i the buffer area. As part of the as-built documentation, a copy of the seed mix tag or invoice that shows the i' variety, origin, and analysis of the seed will be submitted to the USAC E. . , 11.0 RECORD DRAWINGS AND REPORT i Record drawings and report will be submitted after implementation of the mitigation plan. The a report will include the following: �• a • Deviations from original plans • Actual grade contours • Planting locations and types 3 10 ' j Wetland Mitigation Plan Terracon Consultants, Inc. SE 16th Street Ames, Iowa Terracon Project No. 08067012 October 18, 2006 As part of the as-cons tructed documentation, copies of the seed mix tags or invoices that show the variety, origin, and analysis of the seed will be submitted to the USACE. Documentation of 1 the variety and quantity of trees will also be submitted. 12.0 MANAGEMENT AND MAINTENANCE OF MITIGATION SITE The mitigation site will be visited once a year until the mitigation site is established. The site visit will consist of observing wetland vegetation, recording growth progress, and noting whether wetland vegetation is competing with invasive weeds. Information collected from the field will be reviewed to recommend best management practices for the mitigation site. The USACE will receive a progress report annually until the mitigation site is established. Based on our experience in wetland mitigation, we believe that the standard five-year annual monitoring period is generally sufficient to determine if wetland features and goals are being met at each phase of the project. During each of the annual monitoring reports damage and mortality of the vegetation and trees will be assessed and the need for additional seeding or plantings will be evaluated and discussed. Following the monitoring period, the need for additional monitoring will be assessed if the wetland goals are not being met. 13.0 GENERAL COMMENTS L The analysis and opinions expressed in this report are based upon the data obtained from.field studies and surveys at the indicated locations and from other information discussed in this report. This report does not reflect any variations that may occur across the site. The client should understand that a mitigation plan is a conceptual design to outline the detail of wetland mitigation activities proposed for the site for regulatory approval. It should not be relied upon for construction. We recommend that detailed engineering plans and specifications be developed upon approval of this plan and prior to construction. This report is prepared for the exclusive use of our client for specific application to the project as discussed and has been prepared in accordance with generally accepted local assessment s practices within the scope of the client's directives. No warranties, either expressed or implied, are intended or made. 11 �„� #., ,'Z ♦ � [1*^t __ z � .,,fir r ? ��,� � �• �,���. 7F} S� `.z t � `t-� .rn � art 1 — .,,.. ":fir, o t ♦ � �,�. �^4� t � ':e ���''� - s • •1 — a ar if Rt "�S L a — Y.�� ••. �f __ �i� •. t 1 y � 5� ��4 'ice i.�"� j'�.-tti .i�i �: i (_• `jam.�, �` •..r � � !t'r � .�; �"; #}jam.. � • - � „yi'�{' f f` .t.I �{yi ♦ r � t. `t' h+off�+�5 �.. ,l. y O i C m N N c0 * F - C a) a ' � = Q .. O ca a) co a 0 a) : a co E nmi ^ O `—�� a) a) o v ��,cn 3 - 3 Q. 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C ca m � ,N o r � 30 3. o a 100 `-�� n E �� o 0 0 0 CD � � "�� 30 � moa) CD 3 o m I N m ° m o a E n� y m ° m "� i _O _o L- L- L - -CC a) _ ° i O tU a) y t y_V _ _ O N O r r CDO c C 'C L °) a "0E l_`a c=a m CO O cop O E E a) � a) = N o �, 0000 C) 00 00 o0C) m 0 o, ° rn.c y m 0000 O 00 00 0000 ._ '3 ° o 3 ro a� m a o o '0 c a) ^ cn a) a ca E c a w ca 'a N M � a) t O am m co co m 0 a) o 0 0 cove 0 0) C) m m c0 3 C N a = E co _ i+ C (j O O O Ln O �t 0 0 r O O O O M O Rf �•' t 5 m000 0 0 0 00 0 66 00 ,- a m 3 m 3 p ! a-0 "°0 � � 0 � cn mm ac0 'a -j3 ro _'i3 '' caE ° E a ° 30 U +.. r=. •t••• CD N O O .0 O cc c\j CO Ln r• 0 o ,- N m c 3 3 3 3 c 0 c cn JJ I J J .j JJ � J _IJJ O o0 OC 2 -a ° 0 C O OO 0 - N .L E O c ° m m m c -C m _ cn � � 0) ° � La) CV Q m 0 v n m Z .� n go += y SEEDING MIXTURES WET MEADOW SITE MIX BUFFER SITE MIX Forbs Forbs Angelica New England Aster Angelica Prairie Blazing Star Blue Flag Iris Prairie Blazingstar Anise Hyssop Prairie Cinquefoil Blue Vervain Rattlesnake Master Black-eyed Susan Prairie Coreopsis Boneset Riddell's Goldenrod Blue Vervain Prairie Dock Canada Anemone Rose Mallow Brown-eyed Susan Prairie Sage Cardinal Flower Sawtooth Sunflower Butterfly Milkweed Purple Conef lower Cream Gentian Sneezeweed Canada Milkvetch Purple Meadow Rue Cup Plant Swamp Aster Compass Plant Purple Prairie Clover Evening Primrose Swamp Betony Cream Gentian Rattle Snake Master False Aster Swamp Milkweed Culver's Root Rosin Weed Golden Alexanders Sweet Black-eyed Susan Cup Plant Rough Blazing Star Grass-leaved Goldenrod Wild Licorice Dotted Mint Roundheaded Bushclover Great St.John's Wort Wild Quinine Evening Primrose Royal Catchfly Ironweed Wild Rose False Aster Showy Goldenrod Joe Pye Weed Willow Herb Fireweed Stiff Goldenrod Marsh Blazingstar Wingstem Flowering Surge Swamp Milkweed Mountain Mint Foxglove Beardtongue Tall boneset Golden Alexander Tall Coreopsis Grasses &Rushes Goldenrod Tick Trefoil Big Bluestem Fowl Manna Grass Great Blue Lobelia Thimbleweed Virginia Wild Rye Dark Green Bulrush Great St.John's Wort Turks Cap Lilly Awl-fruited Sedge Prairie Cordgrass Heartleaf Alexander Upland White Aster Fox Sedge Wool Grass Hoary Vervain White Prairie Clover Illinois Bundleflower Wild Indigo EMERGENT SITE MIX Ironweed Whorled Milkweed Lead Plant Wild Bergamot Forbs Midland Shooting Star Wild Geranium Arrowhead Rose Mallow Mountain Mint Wild Licorice Blue Flag Iris Sawtooth Sunflower New England Aster Wild Quinine Blue Vervain Seedbox New Jersey Tea Wild Rose I Boneset Sneezeweed Ohio Spiderwort Wingstem Buttonbush Swamp Betony Oxeye Sunflower Yellow Coneflower I False Aster Swamp Milkweed Partridge Pea Ironweed Sweet Flag Joe Pye Weed Water Dock Grasses I Marsh Blazingstar Water Hemlock Canada Wild Rye Little Bluestein Bur Marigold Water Plantain Indian Grass Sideoats Grama Grasses, Sedges & Rushes Recommended Tree Species Awl-fruited Sedge Prairie Cordgrass Bottlebrush Sedge Reed Manna Grass Swamp White Oak Northern Pecan Dark Green Bulrush Rice Cut Grass Pin Oak Hackberry Fowl Manna Grass Softstem Bulrush Bur Oak American Sycamore Fox Sedge Three-square Rush Black Walnut Black Cherry Hardstem Bulrush Tussock Sedge Shellbark Hickory Arnold Hawthorn Hop Sedge Wool Grass Bitternut Hickory Green Hawthorn Lake Sedge Recommended Shrub Species Silky Dogwood W ild/American Plum Redosier Dogwood Chokecherry Serviceberry Elderberry Nannyberry r t � rz J •• u aapp ll ail CA S tling Ponds ! ! t0 •M•• ..l' , � �t ss � * I P a ���.. nam DaO6 , o 943 -� t --_—_—_; —_—_— �_— +-'1�1 • is j ,) I �� �,,�� —to f _ HMI H_ _ — - 1 ;� ��-, •'i ._�.�� '�. 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(�Il�lfil our ul�■.ol■lu aui uclroultcul► ur ilnuorulrur. 1/IhU�I �l/ It/lrrlrl/lr►llaa. iiiii.� t\ I�III;y ....i PARKING iiiiiuii�iii� , /a[/alrpaal.lriltlrr/IN,e� LOT t . ni ..�............[ K is 1.■laal■■■ nruutnlrourauouo� �• :.luuatrila■r.■7ll■rr■■r■ ` ` :reuuuolrl.olo■ioI iIlr■l■■rolrr�lr■rrr�lrlr ISO"lrrll��.r/lrl■ir..l■/ L;:.■■:�uruu�rrsov 'rrl�,l■6ll/i�rlalrrw- uoov IN R. BRADLEY STUMBO P. O. BOX 1664 AMES, IOWA 50010 515-233-3689 PLAT OF EASEMENT NE CORNER WETLAND CONSERVATION EASEMENT SEC. 12-83-24 NO MONUMENT N�3 25. FOUND OR SET 4g-w 21s'v2' O o co 0 PARCEL ID: 09-12-300-400 u PROPRIETOR: BRADSHAW FARMS, L.P. REQUESTED BY: DOUG ERNST, p ENGINEERING ALLIANCE, INC. p CU Survey Description-wetland Easement: in W A part Of the Southwest Quarter of J the Southwest Quarter of Section 12, ^ c Q Township 83 North, Range 24 West Of c U O the 5th P.M., City of Ames, Story rn County. Iowa being more particularly described as follows: Commencing at � v the Southeast Corner of the Southwest v to = Quarter of the Southwest Quarter of v CL said Section 12; thence NOO*24'54"W, WETLAND 270.02 feet along the East line of the °; CONSERVATION o Cc Southwest Quarter of the Southwest EASEMENT 0 CD Quarter of said Section 12: thence 129164.26 SO FT v N89'39' 15"W, 80.01 feet to the point of ^ 2.97 ACRES c O beginning; thence N00'24'54"W, 472.90 feet; thence N73'25'46"W, 216.42 feet: ;" z thence S00 '24'54"E, 738.39 feet to a point on the North line of South 65.00 feet of the Southwest Quarter of the Southwest Quarter of said Section 12; o thence 589'39' 15"E, 30.00 feet alongg o said line; thence N00'24'54"W, 10.00 N feet; thence N54'56'38`E, 151.92 feet; thence N00'24'54"W, 107.00 feet; thence S89'39' 15"E, 51.99 feet to the point of beginning, containing 2.97 acres. SB9'39'15"E �N 01 5"W 80. 51.99' 8001' 3 Q • In O . O Q N ^o O O Z O n Iq �gA hb 92 � Vt I1-X�Y �p5E 'n � v N00'24'54"W N N. LINE S. 65' 10.00, SW CORNER _ _ _ 15.00' 257.00' _ Z SEC. 12-83-24 50' ROW LINE _ _ FOUND 1/2" REBAR S89'39' 15`E SE CORNER IN CONCRETE OF 30.00' SEC. 12-83-24 w MH STRUCTURE S89`39'15"E 1307.96' Ln (TO 8E SET FOLLOWING S.E. 16TH STREET (ROW VARIES) CONSTRUCTION) Certification: I hereby Certify that this land surveying bycmeent was or underrrmyared directd the personalated survey supervisionwork was and thatpIramraed OP LEY s CENg Or+ duly licensed � Land Surveyor under the laws of the State of Iowa. Q, p Date: 17161 R. Bradley Stumbif License #17161 My license ren al date is December 31, 2007 IOWA Job #15834BEAS3 Date: 11/22/06 Page 1 of i �aNb SURD