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HomeMy WebLinkAboutSWP272264(19) FILE 1 Co y 1 1 1 1 1 1 1 Maplewood Creek Sedimentation Basin Environmental Assessment 1 FEMA - Region X 1 i 1 i 1 1 1 1 1 G�NGY MA�� Federal Emergency Management Agency Region X 130 228th Street, Southwest Bothell, WA 98021-9796 Februay 27, 1995 MEMORANDUM FOR: Rick Shivar, Environmental Officer Off' of Policy and,�Assessment FROM: arles L. Steele, Director Mitigation Division SUBJECT: Proposed 404 Funds: Maplewood Creek Sedimentation Basin Reconstruction F EMA D R-852-WA Enclosed for your review is a Finding of No Significant Impact made following an environmental assessment of a project proposed to be funded by FEMA Region 10 with 404 funds. Supporting documentation for the Finding of No Significant Impact is the attached Maplewood Creek Sedimentation Basin Reconstruction Environmental Assessment that includes the following appendices: Appendix A. Maps. Appendix B. Project Costs. Appendix C. Environmental Impact Analysis Checklist & Impact Summary Matrix. Appendix D. Executive Orders 1 1 988/1 1 990, 12898 Checklists. Appendix E. Affidavit for Publication of Notices. Appendix F. Letter of Intent. Appendix G. List of Recipients of Letter of Intent. ' Appendix H. Comments Received and Our Responses. Appendix I. Phone Log. Y Appendix J. DSR Report. 1 FINDING OF NO SIGNIFICANT IMPACT f Maplewood Creek Sedimentation Basin Reconstruction City of Renton King County,Washington FEMA-852-DR-WA ■ The proposed project involves the reconstruction and expansion of the retention basin at the Maplewood Golf Course to more effectively capture sediments from Maplewood Creek and prevent those sediments from flowing downstream clogging the waterway and flooding the golf course, Maple Valley Highway, and surrounding residential areas. s ' Two other alternatives to the problem of sedimentation and flooding- No Action, and the Upstream Alternative-were found to be unacceptable or ineffective. Therefore, the proposed action provides the most practical,timely, and cost effective solution to the problem of downstream flooding. Based upon the attached environmental assessment of the proposed project for Maplewood Creek, and in accordance with FEMAs regulations(44CFR, part 10) for r environmental consideration, and Executive Orders 11988, 11990, and 12898, the following is determined: a Finding of No Significant Impact is made on the basis that no long-term significant adverse impact on the natural environment will result from implementing this project. Therefore, ian Environmental Impact Statement will not be prepared, and the project may proceed. ■ Recommended: 3/1/ f Envirionmen&I Revieweolricer D to Flee gional Director Date Approved: Environmental Officer Date Office of General Counsel ate t ' ENVIRO NMENTAL ASSESSMENT Maplewood Creek Sedimentation Basin Reconstruction ' City of Renton King County,Washington FEMA DR-852-WA February 23, 1994 This environmental assessment is a revision of a draft environmental assessment initiated in ' September, 1992, but never completed. This document includes further information and study, particularly of aquatic and terrestrial resources, including sedimentation, soils, and geologic features, and further development of the three alternatives. This project will use Section 404 grant funds ' together with State and city funds to mitigate flooding, and to control sediment disposition of the lower reaches of Maplewood Creek. r I. PURPOSE AND NEED FOR THE PROPOSED ACTION This project is the result of severe flooding and sedimentation in November, 1990, a 70-year storm event, based on rainfall, which produced approximately eight inches of rain over a five-day period. Two holding ponds, located on Maplewood Creek, overflowed flooding Maplewood Golf ' Course, threatening nearby residential areas. Floodwaters from this lower portion of the creek averaged 1 1/2 to 2 ft. deep over three to four acres of the Maplewood Golf Course, and 4 to 5 ft deep over Maple Valley F3ighway(SR 169)making this route impassable to residents and emergency ' vehicles. Deposited sediments were 6 to 12 inches deep on the golf course. This storm cost the city approximately $41,519 to restore the area, 75% or $31,139 was Federally-contributed through FEMA's Section 406 funds. (See DSR in Appendix J). Maplewood Golf Course is a public facility owned and operated by the City of Renton. A previous 1986 storm, though not as severe as the 1990 event, prompted the City of Renton to request funding from FEMA to help restore damaged city property. It is estimated that a major storm could occur in the area every 10 years, with smaller events and periodic flooding in t between. It is also projected that future storms will have a greater potential for flooding the valley around the golf course, because increased upstream development on the Renton Plateau is causing increased runoff to Maplewood Creek. As the creek drops 300 feet through a ravine, any increased flow will accelerate the soil erosion and bank undercutting on the 60 to 70% sloping sides. The existing sedimentation ponds are inadequate to handle stormwater flows. The one upstream at the base of the ravine,resulted from siting of an old water supply dam built in 1930, not for the purpose of sediment control. This older pond is now completely filled with sediment. ' The newer sedimentation pond, located downstream closer to the municipal golf course was built p p ' Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.1 1_ ' for sediment control but is inadequate to do the job. (Figure 1, Appendix A). The proposed action will expand this sedimentation basin to contain more upstream sediment and prevent its flow and clogging of the channel through the golf course, thereby reducing the potential for flooding during future storm events. f II. PROPOSED PROJECT The proposed project(Figs. 2. & 3., Appendix A)involves reconstructing and improving the existing sedimentation basin on Maplewood Creek near the golf course. This reconstruction will ' create a larger storage volume for sediment and debris, and will trap smaller particles. The new basin will have a sediment storage capacity nearly three times that of the existing facility. The existing access road running along the west side of the basin and creek will be improved by placing a gravel road surface. The upper concrete dam will be removed, along with the accumulated sediments, and the upper creek channel will be stabilized to reduce severe channel and bank erosion. The toe of the south bank at this dam is unstable and will be reinforced with riprap to prevent undermining after the dam is removed. A second section of the south bank, located just below the dam will also be reinforced with riprap. r A diversion structure would be installed in the sedimentation basin to direct water to a future low flow fish passage channel that will be constructed through the golf course, a separate project to be constructed later, using other funds. Morespecifically, this ro'ect includes the following elements(Fig. 4 : project g ( g ) * Reconstruction and expansion of the existing lower retention basin, with an outflow weir to provide for fish passage. ( The new basin will have a pool surface area of approximately 12,000 sq. ft. and a volume of 1,300 cubic yards. It is expected to capture a larger portion of fine sand, and trap efficiency should increase from an existing 25% to 50%, or 600 cubic yards.) The pond and channel construction may involve up to 4,000 cubic yards(cy) of excavation and recompacted fill. * Construction of a rectangular bathtub overflow spillway, a 24 ft. long by 12 ft. wide reinforced concrete structure. It is estimated that the frequency of water flowing over the main spillway will be approximately 7 days per year on average, primarily during the winter high flow months. A concrete outlet pipe, 30 ft. long and 72" in diameter will be connected to the spillway. Excessive hydraulic energy of the flows will be dissipated within the spillway, pipe and outlet structural system- * Construction of a fishway outlet on the west side of the sedimentation basin embankment. This will consist of two concrete weir structures connected by a 32 ft. long by 42" diameter concrete pipe buried under the dam embankment. This fish ladder weir will be built with a slight reduction in Environmental Assessment Maplewood Creek Sediment Basin Reconstruction r City of Renton,King County,WA FEMA-852-DR-WA Page No.2 ' hydraulic capacity to allow for excess water flow from the golf course during storm events. ' * Construction of a maintenance bypass pipe (300 ft. long x 12" diameter), including a small inlet and gate structure,will be buried along the west side of the sedimentation basin and access road. This bypass pipe will be used to temporarily divert water from the sedimentation basin which ' sediment is being removed from the basin for maintenance purposes. Sediment removal may take one to two weeks during the summer. ' * The existing access road along the west side of Maplewood Creek and the west embankment of the new sedimentation basin will be improved with a new surface of crushed rock. ' * Removal of a concrete dam that is part of an obsolete holding pond, 500 ft. upstream of the existing sedimentation basin, and removal of accumulated sediments upstream behind this dam. The banks along this stretch, 60 ft. from the dam, will be secured by rip-rap. These improvements will facilitate anadromous fish passage into the upper creek area. Fish passage is now prevented by the dam. At the sedimentation pond below, a new outlet will allow for fish passage, and will ultimately link up with a new fish channel flowing to a newly constructed fish ladder at the Cedar River. This new fishway is a project planned by the City of Renton,with an expected completion date of September, 1995. M. THE ALTERNATIVES Alterative 1: The No-Action Alternative Under this alternative, no project would be implemented. The upper pond would remain filled in and the concrete dam would continue to impede fish migration. The lower pond would stay the same size, with frequent dredging necessary. There would be no improvements to the outflow weir to the future fishway, so there would be no way to connect them, stopping the fish at this point. And the sides of the bank, especially around the upper pond would not be stabilized. On the nearby steep slope, the soil is bare in many places, and significant soil slippage would continue. s Alternative 2: The Upstream Alternative This alternative will provide for regional detention upstream, to control flows through the steep ravine. Two, 30-acre holding ponds would be constructed on the plateau, one on the west fork of Maplewood Creek and one on the east fork. (Fig. 5, Appendix A). t These two ponds would catch runoff and trap sedimentation from the surrounding plateau area. This alternative represents a solution at the source of the problem, and would help to reduce stormflows down the ravine. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.3 ' Alternative 3: The Downstream Alternative (Proposed) This is the proposed action. It represents a downstream solution to the problem of flooding on the valley floor during storm events. The existing sedimentation facility would be enlarged and upgraded to adequately accommodate stormwater flows down Maplewood Creek, and to trap and store sediments so that they do not flow downstream and clog the channel and concrete culverts causing flooding. This upgrade would allow for fish passage from the Cedar River up through Maplewood Creek. IV. DESCRIPTION OF THE PROJECT AREA Maplewood Creek begins with two tributaries on the Renton Plateau, which begin by collecting storm water from the residential areas on the plateau. The east fork and west fork drain an area on the plateau of approximately 1.72 square miles. They join and flow for about 1500 feet C- down a steep ravine, through an old holding pond and over an obsolete concrete weir, into a newer sediment basin,then across the Maplewood Golf Course, through a 100 foot long, 72 inch diameter ' culvert, and into the Cedar River. The drainage area for the proposed sedimentation basin is approximately 1.61 square miles. The project area has three natural p � tura divisions: the upland plateau, the ravine, and the valley and golf course below. ' On the Plateau The headwaters of the east fork of Maplewood Creek is a 11 acre Class 2 wetland. Substantial areas of this wetland have been incrementally filled. As a result, the creek that flows through the wetland has been reduced to a narrow ditch, and areas of the wetland are overgrown with ' weeds. Several small commercial uses appear to have encroached on the oldest portion of the fill; other areas are littered with refuse and old tires. All of this contributes to the reduction of natural water storage in this upland area. Frequent flooding occurs in the Puget Colony Homes plat downstream, and severe erosion has occurred where this fork and mainstem Maplewood Creek descend to the valley floor in the Maplewood Golf Course. If filling continues, the problems affecting this wetland and resources downstream could worsen. The west fork of Maplewood Creek is located mostly within the city limits of Renton, which is entirely sewered. Much development has occurred in the vicinity of this fork. Many of these developments have their own water detention ponds. t ' Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction • City of Renton,King County,WA FEMA-852-DR-WA Page No.4 ' The area where the west pond is shown is open and covered with dense bushes. There is a stream running through it; runoff from the drainage basin north of NE 4th St. flows to this area. ' There are homes along the west side, and some homes south east of the pond area at the end of a rough cul-de-sac. A major subdivision is located about 600 feet south of the pond area. ' The proposed east fork pond is located in an area of King County that is zoned suburban residential, with a minimum lot size of 15,000 square feet. The pond area is mostly wooded with second growth trees. There are several new homes on the north side of the pond area that are on ' larger, partially cleared lots. North of the proposed pond is a subdivision, and northeast is cleared pasture with several large homes. There are also clusters of smaller homes on smaller lots. In summary, overall on the plateau,residential development has significantly increased over ' the last few years. In both east and west forks, habitat is highly fragmented and degraded by development activities, including housing and strip mall development, in-stream ponds, localized filling of wetlands, and extensive networks of roads and culverts. t In the Ravine f From the top of the plateau,the creek drops about 300 feet through a steep, wooded ravine. ' The lower portion of this ravine contains some good habitat despite a riparian system that is still recovering from historic timber harvesting and effects of erosion, and high flows due to upsteam f_ development. Habitat in stream reaches in the upper part of the ravine is heavily affected by channel scour, naturally unstable geologic conditions, and lateral bank sliding. This latter problem is caused, in some instances, by stormwater discharge over the steep banks. ' With the increase in impervious surfaces upstream, stormwater runoff gathers more force and momentum, slicing its way through the canyon. Channels become wider and deeper, and the water undercuts the highly erodible soils along the canyon walls. These walls, looming at a 60%to ' 70%slope, slough off and the sediment washes downstream. Extensive landsliding has occurred and several culverts high on the ravine sides have eroded large gullies that release substantial amounts of sediment. In addition, a large amount of trash, including old tires and appliances, has been discarded in the upper ravine area of Maplewood Creek. The Valley Below 3. Sediments are carried downstream to the inadequate sediment pond at the Maplewood Golf Course. The result: flooding of the golf course and surrounding residential areas, and cementing of salmon spawning areas in the Cedar River. During the 1990 storm, two inactive water supply wells located on the golf course had floodwaters 6 to 7 inches deep at the wellhead casings. Fortunately at that time, these wells were '- inactive. Currently,there are four wells on the golf course, and a new water treatment building. As soon as testing is completed on the treatment building, the four wells will be placed in operation. c �~ Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.5 ' Then, this facility will supply a significant portion of the city of Renton's potable water supply. In the lower half-mile,the creek runs through a largely barren drainage ditch, then enters a culvert system, and flows 1.000 yards underneath SR 169 and the railroad tracks into the Cedar River. Although coho salmon have been reported to migrate through the culvert and into the golf course reach in recent years, the existing culvert system is not ideal for adult fish migration. The Washington State Department of Transportation has recently constructed a fish ladder immediately adjacent to the culvert outlet to the Cedar River. This will be connected to a future fishway channel through the golf course to the proposed reconstructed sedimentation basin. The King County Basin Reconnaissance Program report and the Maplewood Creek Basin study have identified sediment and erosion problems upstream of the project site and significant degradation of the stream channel due to sediment accretion downstream of the project site. Geological Characteristics The Maplewood Creek watershed encompasses 1,099 acres. Determination of sediment yield was based on 1,032 acres, or that portion of the watershed upstream of the proposed sedimentation basin. The geologic environment of the canyon consists of subhorizontally bedded, glacially- derived sediments. Exposures within the canyon display sandy gravel, sand and clay beds,varying in thickness from 1 foot to several feet. Most exposures of bedded sediments are covered by a steeply sloping mantle of gravelly sandy clay with an abundance of organic material. The upstream 0.2 miles of Maplewood Creek show evidence of recent, extensive incision and widening. In the downstream part of the west fork, extensive landsliding of ravine sidewalls and overlying outwash deposits is occurring as banks adjust to past incision. Landsliding probably occurred in the reach prior to development, but has likely worsened by recent downcutting. Near the creek,bank undercutting occurs on nearly every outside bend. Several rotational slope failures were identified. Soil creep is visible under the vegetation cover on nearly every slope. Approximately, 10 significant landslides were observed on the canyon slopes. These unstable areas include raveling slopes undercut by stream action, rotational failures, slope creep, and debris flows. There are two large landslides,but they are marginally stable and appear not to have moved in recent years. The banks around the upper concrete dam are steep and have been reinforced with rip-rap. A gravel/cobble bar is located upstream of the dam. Water depth averages approximately 1 foot. The upper obsolete holding pond is now entirely filled in with sediment, and small and large stones. Through this pond,the creek is shallow and wide,then drops 10 to 15 feet over the old concrete dam. The golf course maintenance supervisor reported that the existing sedimentation basin has been cleaned out every year except 2 during the last 9 years. It was also cleaned out after the Environmental Assessment- Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.6 ' November 1990 flood event. While 165 cy/sq mi/yr is an average suspended sediment for the lower Cedar River Basin,Harza, a consultant for the city of Renton, estimated that an average of 1200 cy ' per year of sediment is transported to the existing sediment basin on Maplewood Creek. The existing basin traps 250 to 300 cy per year, and the remaining 900 cy passes through the system and is deposited in Maplewood Creek on the golf course, or to the Cedar River. While the downstream sedimentation facility is being constantly loaded with sedimentation, the stream bed upstream in the area of the slides and unstable slopes is remarkably free of debris. The channel floor is covered by a thick blanket of sand and gravel possibly up to 10 feet thick. Organic debris, such as logs, bridge the creek but intermittent stream flows have been high enough to strip most fine organic debris from the channel. Aquatic & Terre strial estrial Characteristics While the Cedar River has a large run of sockeye salmon, steelhead and a moderately-sized run of river smelt, except for isolated sightings in the golf course stream channel, migratory fish do not use Maplewood Creek for spawning and rearing. Resident trout have been observed in the lower reaches of the creek, from the golf course area upstream into the steeper canyon reaches. This section of stream was restocked by citizens a number of years ago with trout provided by the State Department of Game. Erosion in the steep, lower reach of the east fork of Maplewood Creek has washed fine sediments into potential spawning gravels and significantly impacted fish habitat. In addition, the two ' ponds downstream at the golf course are a barrier to fish passage. The upper concrete dam is severely damaged and undermined severely eroding the channel bottom. The lower dam also lacks adequate fish passage. The continued presence of trout upstream of these ponds indicates that water quality within the creek is adequate. However, during high stream flows, turbidity levels significantly increase, and these levels may be limiting the population of resident trout. Duringsite visit,a Harza observed evidence of 10 significant landslides on the canyon slopes. Yet,the stream channel was remarkably free of organic debris. Some logs bridge the creek but intermittent stream flows must be sufficiently high to strip most fine organic fragments from the channel. Two minor canyon debris jams were found but these do not impede the normal stream flow. The channel floor is covered by a thick blanket of sand and gravel, up to 10 feet thick. A search of the Washington Department of Natural Resources Natural Heritage Information System indicates that no record of rare plants, high quality native wetlands, or high quality native plant communities exist in the project vicinity. The vegetation in the area is comprised of common species indigenous to western Washington. The forest canopy is fairly open, and a well-developed shrub and herbaceous layer is present. The tree species include western hemlock, western redcedar, Douglas fir,red alder, and bigleaf maple. Along the riparian zone, there is salmonberry, Himalayan blackberry, snowberry, red elderberry, vine maple, devil's club, and currant. Environmental Assessment-Maplewood p wood Creek Sediment Bann Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.7 Vegetation in the lower portion of the creek, near the sedimentation ponds, consists of ' smartweed,mixed grasses,Robert's geranium,horsetail, dandelion, plantain, hairy cat's ear, clovers, creeping. buttercup, western bittercress, reed canarygrass, snowberry, salmonberry, elderberry, blackberry, and vine maple. Residential development on the uplands above the ravine and recreational development below the project area restricts the diversity of wildlife in the project area. Because of limited amount of vacant land, forest and riparian-dwelling wildlife species, with moderate to small home range requirements may exist there. These include deer, birds, waterfowl, small mammals, reptiles, and amphibians. During a site visit, deer sign, a mallard pair, and rodent carcasses were observed. Although raccoon sign was not observed, its habitat is present. Cavities were evident in scattered snags and coniferous and deciduous trees. Cavity nesting species likely to occur in the area include common flicker,winter wren, squirrel,black-capped chickadee. Gravel substrate and sandbars, in the shallow waters of the lower sediment pond, likely provides foraging platforms for the great blue heron. It is possible, then, that this heron may be present in the general area. However, it is unlikely the heron would use the project area. Because the pond is isolated, partially hidden by trees, and is walled in by the sides of the ravine, it is more likely that the heron would use the shallow areas of the Cedar River that are much more easily accessible to them. The golf course supervisor has not seen any in the area. Floodplain ' A wide swath in the golf course along SR169 was a designated floodplain, Map No. 53033C0329, as shown on FEMA's Flood Insurance Rate Map. This area has now been deleted from this designation. Further study of this area revealed that the floodplain classification was not justified because overflow of the Cedar River does not occur here. The elevation of the natural berm between the River and the golf course is higher than the 100 year flood. Therefore, this area was removed from the Flood Insurance Rate Map (FIRM), by action of this office. Rare or Endangered Species A search of Washington Department of Fish&Wildlife(WDFW)records indicate that there are no species of concern within the project area. A search of the U.S. Fish and Wildlife Service database for threatened, endangered, and sensitive species indicated that bald eagles could be present in the project area during the winter. However, WDFW shows no record of bald eagle nesting, roosting, or concentrations in the vicinity. R Historical or Archeological Sites ' The City has reviewed the eligibility criteria of the Washington State Historic Preservation Office and City records to establish any historical significance of the old concrete dam, upstream of Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.8 ' the sedimentation basin,built in the 1920's for irrigation control. The conclusion is that this structure does not meet this criteria. It is a simple concrete structure with no distinguishing marks. It shows ' signs of age; parts have broken off It is not a unique engineering structure and is not one-of-a-kind. ' Coordination With Other Plans The proposed action intertwines with two other projects in the area: the construction of a fish ladder and fishway through the golf course, and the construction of a new golf course clubhouse. Moving the clubhouse to another site close to SR 169 will vacate space needed for the ' reconstruction and enlargement of the sediment basin, and connection to the future fishway. Now that the land to be used for the new clubhouse site is taken out of floodplain designation, the way is clear to proceed with the clubhouse construction. The new clubhouse is expected to be completed by December, 1995 or January, 1996. The improvements on the west side of the golf course, including the revised fairways, new greens, and new irrigation system will be completed by July, 1995. Design of the low flow fish passage channel should be completed this spring, 1995, with construction completed in the summer/fall of 1995. It will not be usable for fish migration until the fall of 1996, after the new sedimentation basin is completed and connected to it. Community Planning The proposed project is consistent with all comprehensive plans and zoning requirements. The project proponent will be required to apply to the U.S. Corps of Engineers for a Section 404 permit, a Washington Department of Fisheries and Wildlife Hydraulic Project Approval, a State Department of Ecology Short-term Water Quality Modification, and utility(grading) Permits. a Maplewood Creek has a mean flow of less than 20 cfs; therefore, a Shoreline Substantial ' Development Permit is not required. V. ENVIRONMENTAL IMPACTS OF ALL ALTERNATIVES The Impact Summary Matrix in Appendix C,provides a concise look at all possible impacts on all the alternatives for this project. Alternative 1: Impacts of the No-Action Alternative If no-action is taken, damage from high flows of stormwater runoff and heav y sedimentation would continue. B not enlarging the sedimentation basin at the golf course flooding of the Y g g g g valley would Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.9 continue unabated in the future. It is anticipated that a major storm and flooding event will occur p J g there every 10 years. But the impact of no action may contribute to a worsening situation in the ' future, because as development continues on the plateau, more impervious surfaces will be created with subsequent increase in non-point runoff. Because of the highly erosive soils in the ravine, any increase in runoff will result in increased erosion and siltation downstream. Already with no action, the upper holding pond has been completely filled in. In the lower basin, increasing sediment deposits will require more frequent dredging and expense to keep this pond functional. If this pond fails, then there is a greater probability that even lesser storm events will cause flooding of the golf course and surrounding areas. In this alternative, wildlife would not be displaced; however, it would be negatively impacted. The possibility of future salmon runs up Maplewood Creek would be eliminated. The dam at the obsolete upper pond would continue to be an insurmountable barrier to migratory fish. No action would not be consistent with other plans for the area. A fishway channel from the sedimentation basin to the Cedar River is in the planning stage;however a significant amount of money and effort has already been spent. Construction of a fish ladder at the confluence of the fishway and the Cedar River has recently been completed. In addition, construction is beginning on a new clubhouse at a new location. Relocating the clubhouse is freeing up land for the expansion of the sedimentation pond. This alternative would continue the existing flood hazard and potential damage to existing residential structures,public park and golf course,public water supply wells, commercial structures, and the Maple Valley Highway which have an estimated value of$2,871,000. In addition, a fishway would not be provided. Alternative 2: Impacts of the Upstream Alternative This alternative would help control stream flow at the source. Excess runoff would be detained in these ponds, and gradually released downstream to help prevent the rush of water through the ravine during storms. It would help maintain a more even flow down the canyon. Reducing the flow amount and velocity during heavy rains will have a beneficial impact of reducing the degree of erosion,undercutting, and sloughing of the sides of the ravine. However, erosion in the ravine would still continue because of the type of soil and steepness of the ravine sides. Even with source mitigation, downstream properties would be subjected to the adequacy of upstream detainment facilities. Should they fail or not prove to be adequate, the current, inadequate downstream facilities would not provide the necessary security from flooding. Though these ponds may capture significant runoff upstream, they cannot detain all non- F 11" point source runoff during a storm event. Significant amounts of runoff could still find its way into this steep ravine fi-om all sides, swelling the creek and still undercutting the sides of the ravine, releasing the sediment that causes the flooding downstream. t" Environmental Assessment-Maplewood M plewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.10 Construction of these ponds would have an impact on wildlife, since a certain amount of ' wildlife habitat would be displaced. In addition,handling this problem only from the plateau does not provide for fish passage upstream to the canyon reaches of Maplewood Creek. f ' ' Constructing detention ponds on the east fork and west fork of Maplewood Creek will have an impact on nearby property owners. Both forks of the river are surrounded by development. Therefore, it will be necessary to purchase private property to accommodate these facilities. This alternative is also complicated by the fact that the west fork of Maplewood Creek is located within the Renton city limits, and the east fork is located in King County. The area of the plateau within the city limits is sewered, and the area within King County is unsewered. The east fork pond would be located in and would serve the unsewered area of King County;however, the west ' fork pond would be located in the sewered area and would also accommodate runoff from unsewered areas in King County. This project would take an extensive amount of interjurisdictional coordination and cooperation. Some mitigation of the problem at its source is alreadyoccurring. Since June 1990 the City g F of Renton has required all new developments to comply with the design standards contained in the ' 1990 King County Surface Water Design Manual. These design standards require stricter on-site surface water controls than required prior to 1990, and will control future flows from new developments. Additional controls may still be required to regulate flows through the ravine to a level which will ensure protection of existing fisheries habitat. The entire plateau is undergoing extensive development. The developments on the west side of the West Maplewood Creek tributary have been built following surface runoff guidelines, and therefore have holding ponds to accommodate runoff from these plats. However, areas to the east of West Maplewood Creek tributary are older developments and many do not have water retention facilities. Alternative 3: Impacts of the Downstream Alternative(Proposed Action) This alternative would solve the continuing problem of flooding of the golf course,valley floor and residential areas, as a result of inadequate carrying capacity of the sedimentation pond, and overflow of sediment and blockage of downstream channel and culverts. The proposed new pond is expected to capture a larger portion of the fine sand than the existing pool. It's larger area and volume will allow a greater volume of sediment to be trapped before efficiencies are lowered, and will allow the water to slow and spread over a greater area, reducing turbulence. Environmental Assessment-Maplewood p d Creek Sediment Bann Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.11 ' No adverse impacts to fish and wildlife are anticipated, except the short-term disturbance P during construction and revegetation planting. No potential habitat would be removed, since the ' expansion of the sedimentation basin will encroach into an existing asphalt paved parking area. The only potential rare and endangered species in the area is the bald eagle. It could be a winter visitor to the area and would not be affected, since construction of this alternative is planned during the low- flow period in late summer. This alternative has a beneficial impact on aquatic habitat. The improved sediment pond and stabilized upstream banks would not only allow anadromous fish to pass to upstream reaches, it would reduce the frequency of sediment removal with its associated costs and its impacts to habitat. This project would significantly decrease the flow of sediment downstream. This proposed action would enhance the habitat for salmonids not only within the reach of the golf course, but also upstream and would encourage use of the relatively good habitat of the Maplewood ravine by anadromous salmonids. 4 Exposed soils will be revegetated creating new habitat that does not now exist. Overturned and piled dirt overgrown with grass and weeds now surround the sedimentation pond. Species selected will promote diversity in areas currently dominated by grasses and weedy forbs. New shrubs ' along the new pond margin will provide cover and increase forage opportunities for many species of reptiles, amphibians, small mammals, and birds. Planting of sedges, rushes and bulrushes in shallow water areas of the pond will add another element of habitat diversity. This project will help protect the potable water supply for the city of Renton, which comes ' from 4 wells located on the golf course. Without this project, future flooding can be expected. Flooding could damage these structures and may preclude the use of the wells and treatment building until they were inspected and tested for contamination. During the 1990 storm event, floodwaters were 6 to 7 inches deep at the wellhead casings of the two inactive wells. Y During construction, minor dust and exhaust emissions from construction vehicles may result for approximately 1 to 2 months. The impacts of construction-related emissions will be minor in comparison to the widening of State highway SR 169. Water trucks will be used to reduce dust during construction. No off-site emissions will occur. This project is consistent and coordinates with other plans for the area. It is one of the recommended projects outlined in the Preliminary Draft of Cedar River Basin and Nonpoint Action Plan by King County. It also integrates with two other projects: the relocation of the clubhouse and the creation of a fishway. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.12 VI. CONCLUSION The proposed action is consistent with the Watershed Management Committee Cedar River Preliminary Draft Basin and Nonpoint Action Plan prepared by the King County Department of Public Works, Surface Water Management Division, and the Cedar River Watershed Management Committee. This project also interfaces with local planning efforts. Channel improvements within the golf course area are a part of the long range plan for Maplewood Creek enhancement. New culverts and fish facilities are planned as part of the improvement to the Maple Valley highway. The proposed project would be a cost effective (Appendix B), hazard mitigation action having virtually no adverse impact upon the environment. It is concluded that the public welfare will be best served by this project, and that it will not have significant adverse impacts upon the natural or human environment. The site is no longer within a mapped flood plain nor any adjacent Wetland. Therefore, the issuance of a Finding of No Significant Impact under the provisions of the National Environmental Policy Act is recommended. t Environmental Assessment-Maplewood Creek Sediment Basin e P Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.13 VIII. APPENDICES Appendix A Maps. Appendix B. Project Costs. Appendix C. Environmental Impact Analysis Checklist &Impact Summary Matrix. Appendix D. Executive Orders 11988/11990, 12898 Checklists. ' Appendix E. Affidavit for Publication of Notices. Appendix F. Letter of Intent. Appendix G. List of Recipients of Letter of Intent. Appendix H. Comments Received and Our Responses. s - Appendix L Phone Log. Appendix J. DSR Report. t Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA FEMA-852-DR-WA Page No.14 BELLEVUE --�� ---- — ------, , . .. ram' iA _ . PIibC-- _ { KQE'10W 1`l < _ 1 _ - 9 _ r 1 -G)i:v"tiG - - 1 _ _ - _ WY PAFK 71 r - - t L E—, ti C` 1 S ^ - 111 yI r 1 1 1 1 9Q'MY \ `t- CEMETERY Ro � PARK _3 :Project Location i-1u rATH EXX t �(1� cty saa ` CEWR PAW UKWILA P/NC PAW F" VFIxY i i uAptE V�EEEY r� r— Ro 1 1 V I I 1 1 I \ 1 �1 1 1 1 1 1 A - I I 1 �� Ll Q ASSJRt _ 1 1 � _ I SPRING UA eoaFrum � - ?i F J � I Htt EXHIBIT A - VICINITY MAP W K . CITY OF RENTON KENT 1pc1,7BrR rasr Sc SCALE: 1" = 6,000 Ft t �.000 r. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton, King County,WA FIGURE 1. A-1 � _ _. a _ • `` ' 406 I , \ West Branch - 4 l: \ 111 \li - ;� , \� •. 1 _ East Branch fill Maplewood Creek ~•`••••'; Upper Dam �• ��••��•� Existing Sedimentation •.• •• •.•� ` �/• '•• / • Basin 0 II - LL • .II. G01f 'moo `� '�; • CO ON �i• Ile `lam/\ ■ • •1 `1� N SOURCE: U.S.G.S.RENTON SHEET, 1:24,000 N 1000' V4jAJZ7_A NORTHWEST, INC. T Environmental As sessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA �" A-2 FIGURE 2. 3 �JTREES� 2 ( 1 Z.Z: Repair and Stabilize Creek Channel - Remove Old Concrete Dam s ' \ z o Renovate Existing Access/Maintenance Road K Reconstruct Existing Sedimentation Pond, -.- '� �- rJ � Provide New Contrd Structure i t 11 Proposed Salmon Habitat Channel(Separate Project) TS � - ` . MAPLEWOOD GOLF COURSE l� \ GOLF COURSE \\ M. A P L'k W O O D �r t — > aySR�69 EXHIBIT B - SITE MAP X ` CITY OF RENTON }-� SCALE: t" = 200 Ft. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction W, City of Renton,King County,WA A-3 FIGURE 3. L.. _ 20" HEmL .` �� 1 T / I 30 MAPr` o\ �• �� 1 I 1 i ILPLE �U i /Ca / / \ ' Iff� � '• 4'0 FISHWAY .� . / / — I_ /h PIPE / In / 1i , J SPILLWAYCREST - EL 107 „-/ FISHWAY C HANNEL !/ (FUTURE) DAM CREST EL. 110 7� 6'0 PIPE OUTLET ! / I , I/8 EXMBTT 2 �` � i it i ';'�'fi j•L/,_; '/ i 0 15 30 6 to `v. SCALE 1N FEET 1 r� _ �•;��\\= ��`\` DATE: 25-94 .�` E: 5— 9 Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton, King County,WA A-4 FIGURE 4. ,A i IL MEIautS 41991 3S f .I ....I c 1"7S WM 3N . .r.....AiNnoo LJ FJ I i 4-)01>oAuotuaa ILJ tl wogs 41113N 1 �1 .�..� r....... V^1 �� 1 ( l lae�ls 419Zt 3S L � IRA o _ - WDc_i _ A_ _ a `g , I nE� afield PuZ 3S leans V18Ct pO FE U O Y Y • C �lllrl 3S — V U 3 c te loans 0 2 row /\v�yt` 11 "UZ 2 00U U .'1 l 111 � wa1S puZot 3S - .. 'Wnoo -. , •�os�»�to�Ila•,'`~'• •' _ 69 00 �•� ��\\ jay/,' r/ }}/` I b, t "•.t 4C���.�•/Vl ll).�!J F!/\�'7'' � peg �^ Environmental Assessment-Maplewood p ood Creek Sediment Basin Reconstruction City of Renton, King County,WA A-5 FIGURE 5. APPENDIX B Project Costs Clearing & Grubbing $4,000 F Basin/Dam Embankment $35,200 Overflow Spillway & Outlet $24,530 Fishway Outlet& Flow Bypass $17,820 Upper Dam/Sediment Removal $5,700 Bank Slopes Repair $8,810 Access Road Upgrade $3,000 Stream Habitat Improvements $3,500 Mobilization & Misc. $27,178 Engineering & Permitting $50,000 ' Administration $6,000 Sales Tax 8% $10,379 The total estimated direct construction cost is $129,738, with the total estimated cost at $196,117. e f Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA B-1 APPENDIX C ENVIRONMENTAL IMPACT ANALYSIS-Ma lewood Creek Sedimentation Basin ALT.1 ALT.2 ALT3 ISSUES No Action Upstream Downstream LAND USE AND SOCIOECONOMIC ISSUES BLANK=NO Inconsistent with land use? Conflict with zoning ord? Relocation of structures? F Effect on economic activities? YES Effect on parks or rec.areas? Coastal Zone Const.Determ.? Other: AIRJWATER QUALITY ISSUES Air Quality? YES YES Dred in /Dis oral in water? Modification of Waterway? YES YES Other: NATURAL RESOURCES Removal of vegetation? YES Const.in marshlands/wetlands? YES Endangered species? Wildlife refu a/conser.area? Other: ARCHEOLOGICAL AND HISTORIC? ArchJCult/Hist Sites? Other: Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA C-1 IMPACT SUMMARY MATRIX FOR MAPLEWOOD CREEK SEDIMENTATION BASIN DESCRIPTION NO-ACTION ALT. UPSTREAM ALT. DOWNSTREAM ALT. A. Description of Alternative No project would be implemented. Provides for regional detention This is the proposed action. The upper pond would remain filled upstream,by creating two holding Provides for expansion of the in and the concrete dam would ponds, one on the west fork and one retention basin at Maplewood'Golf continue to impede fish migration. on the east fork of Maplewood Course, to prevent sediment The lower pond would stay the same Creek. overflow and potential flooding of size, with no improvements to the the channel below. Construction of outflow weir, an outflow weir to a proposed fishway to the Cedar River. B. Potential Impacts Geological, Soils, Seismic Continued erosion & sediment flow, Reduces and controls stormwater Traps sediment so that it can be flow through the ravine, reducing removed. Significantly reduces erosion and sedimentation sediment flow in downstream reach downstream. of the creek, providing a direct reduction of valley flooding. Also, secures sides of lower ravine with riprap. Prime & Important No impact. No impact. No impact. Farmlands Wetlands No impact. No impact. No impact. Wildlife Resources No impact. Potential adverse impact of Beneficial impact os helping to displacing wildlife for siting of the establish anadromous fish runs up two retention ponds. the river. Revegetation around detention pond will create habitat for wildlife. Threatened & Endangered No impact. No impact. No impact. Species Air Quality No impact. Minor&temporary construction- Minor&temporary construction- related air quality impact. related air quality impacts. C-2 Water Resources Continued sedimentation of Some reduction of sedimentation by Sedimentation will be controlled by downstream reaches of river. controlling flow. rip rap and an enlarged holding pond, resulting in better water quality downstream. Floodplain Management No impact. No impact. No impact. Downstream of the project site is a floodplain area #53033C0329. This area is now being removed from floodplain status. The project favorably impacts this area by reducing the potential for flooding in this low lying area from the creek. Socioeconomics Future flooding could threaten Building these two ponds will Will have a beneficial impact by residential developments near the require the purchase of private directly protecting nearby low lying golf course. property. Could be costly. residential areas from flooding. Noise No impact. Minor, transient noise impacts Minor, transient noise impacts during construction. during construction. Visual Resources No impact. Would change the visual character of The expanded retention basin will be the upstream reach of the two forks, visually appealing, looking more like creating ponds which will,replace a lake surrounded by new plantings. trees and pastureland. Also visually appealing will be the projected new fish runs up the fishway, through the expanded pond, and up the ravine in the creek. Historic Structures No impact. No impact. No impact. Archaeological Resources No impact. No impact. No impact. Infrastructure Negative impact. Will not interface Negative impact. Will not interface Positive impact. Provides with two other projects that are with two other projects that are connection to fishway, and is already in process. Will not connect already in process. Will not connect consistent with official plans and Masplewood creek to d future Masplewood creek to a future policies for the area. Will help fishway;the fish ladder at the Cedar fishway;the fish ladder at the Cedar prevent flooding of SR 169. River is already built. River is already built. C-3 APPENDIX D 1 EO 11988/EO 11990 CHECKLIST EXECUTIVE ORDER NO. 11988- FLOODPLAIN MANAGEMENT EXECUTIVE ORDER NO. 11990 -WETLAND PROTECTION FEMA-852-DR-WA PROJECT NO. 0002 1 TITLE: MAPLEWOOD CREEK SEDIMENTATION BASIN at Maplewood Golf Course City of Renton,King County,Wa. STEP NO. 1 DETERMINE WHETHER THE PROPOSED ACTION IS LOCATED IN A WETLAND AND/OR THE 100-YEAR FLOODPLAIN(500-YEAR FLOODPLAIN FOR CRITICAL ACTIONS), OR WHETHER IT HAS THE POTENTIAL TO AFFECT OR BE AFFECTED BY A FLOODPLAIN OR A WETLAND. iThe project is not located in a floodplain. The project is located in a floodplain as mapped by FIRM No. X The project is not located in a Wetland. The project is located in a Wetland. STEP NO. 2 NOTIFY THE PUBLIC AT THE EARLIEST POSSIBLE TIME OF THE INTENT TO CARRY OUT AN ACTION IN A FLOODPLAIN OR WETLAND, AND INVOLVE THE AFFECTED AND INTERESTED PUBLIC IN THE DECISION- MAKING PROCESS. X Not applicable- Project is not located in a floodplain or in a Wetland. Applicable-Notice will be or has been provided by: Public notice was previously published in newspaper with circulation in Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA D-1 the area and letters to Resource Agencies t STEP NO. 3 IDENTIFY AND EV ALUATE PRACTICABLE ALTERNATIVES TO LOCATING THE PROPOSED ACTION IN A FLOODPLAIN OR WETLAND (INCLUDING ALTERNATIVES SITES, ACTIONS AND THE "NO ACTION" OPTION). ' IF A PRACTICABLE ALTERNATIVE EXISTS OUTSIDE THE FLOODPLAIN OR WETLAND, FEMA MUST LOCATE THE ' ACTION AT THE ALTERNATIVE SITE. X Not applicable- Project is not located in a floodplain or in a Wetland. Applicable- alternatives identified in the Environmental Assessment Document. STEP NO. 4 IDENTIFY THE FULL RANGE OR POTENTIAL DIRECT OR INDIRECT IMPACTS ASSOCIATED WITH THE OCCUPANCY OR MODIFICATION OF FLOODPLAINS AND WETLANDS AND THE POTENTIAL DIRECT AND INDIRECT SUPPORT OF FLOODPLAIN AND WETLAND DEVELOPMENT THAT COULD RESULT FROM THE PROPOSED ACTION. X Not applicable- Project is not located in a floodplain or in a Wetland. Applicable- associated impacts identified in Environmental Assessment Document. STEP NO. 5 MINIMIZE THE POTENTIAL ADVERSE IMPACTS AND SUPPORT TO OR WITHIN FLOODPLAINS AND WETLAND TO BE IDENTIFIED UNDER STEP 4,RESTORE AND PRESERVE THE NATURAL AND BENEFICIAL VALUES SERVED BY FLOODPLAINS, AND PRESERVE AND ENHANCE THE NATURAL AND BENEFICIAL VALUES SERVED BY WETLANDS. X Not applicable- Project is not located in a floodplain or in a Wetland. _Applicable-Mitigation measures identified in the Environmental Assessment Document. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA ' D-2 ' STEP NO. 6 REEVALUATE THE PROPOSED ACTION TO DETERMINE FIRST, IF IT IS STILL PRACTICABLE IN LIGHT OF ITS EXPOSURE TO FLOOD HAZARDS, THE EXTENT TO WHICH IT WILL AGGRAVATE THE HAZARDS TO OTHERS. AND ITS POTENTIAL TO DISRUPT FLOODPLAIN AND WETLAND VALUES AND SECOND, IF ALTERNATIVES PRELIMINARY REJECTED AT STEP 3 ARE PRACTICABLE IN LIGHT OF THE INFORMATION GAINED IN STEPS 4 AND 5. FEMA SHALL NOT ACT IN A FLOODPLAIN OR WETLAND UNLESS IT IS THE ONLY PRACTICABLE LOCATION. t X Not applicable- Project is not located in a ' floodplain or in a Wetland. _Applicable-Action proposed is located in the only practicable location. _Applicable-Action proposed is not located in the only practicable location. STEP NO. 7 PREPARE AND PROVIDE THE PUBLIC WITH A FINDING AND PUBLIC EXPLANATION OF ANY OF ANY FINAL DECISION THAT THE FLOODPLAIN OR WETLAND IS THE ONLY PRACTICABLE ALTERNATIVE. X Not applicable-Project is not located in a floodplain or in a Wetland. F ' _Applicable-Finding is or will be prepared. STEP NO. 8 REVIEW THE IMPLEMENTATION AND POST -. IMPLEMENTATION PHASES OF THE PROPOSED ACTION TO ENSURE THAT THE REQUIREMENTS OF THE ORDER ARE FULLY IMPLEMENTED. OVERSIGHT RESPONSIBILITY SHALL BE INTEGRATED INTO EXISTING PROCESSES. X Not applicable-Project is not located in a �. floodplain or in a Wetland. _Applicable- Approval conditioned on review of implementation and post-implementation phases to insure compliance of the order(s). Applicable- Oversight responsibility sp ty established. Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA D-3 EXECUTIVE ORDER 12898 Environmental Justice in Minority Populations & Low Income Peoples Maplewood Creed Sedimentation Basin Reconstruction City of Renton King County, Washington FEMA-852-DR-WA YES NO ■ 1. Are there concentrations of minority or low income populations in or near the project area? _x 2. Does the proposed project adversely impact the health or physical environment of minority or low income populations? X 3. Action, if impacted: 1) Change 2) Mitigate D-4 ' APPENDIX E AFFIDAVIT OF PUBLICATION Karen Tucker being first duly sworn on oath ' states that he/she is the Chief Clerk of the VALLEY DAILY NEWS 600 S.Washington Kent,W._98032 ;Daily newspapers published six(6)times a week.That said newspaper ,is a legal newspaper and is now and has been for more than six months prior to the date of publication referred to, printed and - '- I published in the English language continually as a daily newspaper in Kent, King County, Washington. The Valley Daily News has been approved as a legal newspaper by order of the Superior Court of the State of Washington for King County. The notice in the exact form attached, was published in the Valley Daily News(and not in supplement form)which was regularly distrib_• uted to the subscribers during the below stated period.The annexed notice a Public Notice �r i-was published on 7-30-92 The full amount of the fee charged for said foregoing publication is the sum of S 70.28 ,,{( Subscribed and sworn beforemethis 30th - dayof July 1992 -' PueucNoncE --•• -_ _ wificar-is he1ebi'1TKn that rt is the Ghent Of the FEDERAL EMERGENCY MANAGEMENT AGENCY(FE".based on the re—r—datitrs of#m state d Wasfunpt to mitbrssa dro City of P. Notary Pubic for the State of Washington 1on k'r eGpble costs k cured for the pro- Posed wrsbuaion d a good furyard muiga- residing at Kent wn W*cL The decsion•wid be,,.d. King County,Washington kd�*a an wwwmrxruat artaysis d 9ro •vow.a n..:w rrnr proiecrs etleu on the tloodpWnAbtlarids .... --_•-_--.._ -- - — - and A fwafaq 1lterofrom d no spn7frcant impact,Pursuad to re9uirertxms of ero . N�Pmied corn. I d debris' and so• rrxnWion Partd rewrsavdicn and itprove• nWA W is b001 d on the Maplewood Gott Course alorq Cedar Rw The project e tonP1bFe Worb Oe by City d Reif Fb the neat 15 dayi fea-*v dta ndim plars for ek proprsa(A map d the area and $=MOM of Project work may be irupeaed d*dwm dke hoes at City d Rmbn statace Water lh3ty,2W"Ave- nue Soutk Rxsort WA 99055 Tot p M T77-&547.Written owmtmro ma be a4 rrwW to Robert G rme'eag•bwiourtersal Review'Officer,Regcn X.r<i W Reg-w Ceder.130-229dt St-s.W_900eC.WA 9e021-9M (+- Pubrsled in Ow Vatfey Daily News.kdy REC:E 1t\ —.- 30.19W-7e29 AUG 4 10122 - - FEMA-F.-a!G.:x Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA E-1 APPENDIX F Federal Emergency Management Agency a Region X off° o a� 130 228th Street, Southwest Bothell, WA 98021-9796 ' January 13, 1995 Jacqueline Wyland, Division Chief Environmental and Technical Services Division National Marine Fisheries Service NOAA - Department of Commerce 525 N.E. Oregon Street, Suite 500 Portland, Oregon 97232 Dear Ms. Wyland: Extreme flooding of rivers and streams in western Washington in January 1990 resulted in a Presidentially declared disaster. Since then a number of local jurisdictions in the disaster area have developed proposed flood hazard mitigation projects and have applied to the State of Washington and the Federal Emergency Management Agency for funding assistance under the provisions of Section 404 Public Law 93-288, as amended. Among those is an application by the City of Renton. This application proposes: Reconstruction of the existing lower sedimentation pond, approximately 0.18 acres, at Maplewood Golf Course, 4000 Maple Valley Highway (SR 169) in Renton, SW 1/4 Section-15, Township 23N, Range 5E. Construction of a fish flow channel. * Removal of existing concrete dam. Stabilization of the upper creek channel to reduce bank and channel erosion. In September 1992, an Environmental Assessment was initiated b FEMA Region glon X, however, this document was never completed. We are in the process of incorporating new information in a revised Environmental Assessment. We would appreciate receiving your comments on this flood hazard mitigation proposal within the next 15 days. We intend to evaluate the effects of this proposal on the natural and human environment, as required by the National Environmental Policy Act, prior to participation in funding the work. We appreciate your response even if you agree entirely with this project. We are seeking as much feedback as possible to be able to offer a more complete document for review. Environmental Assess in en t-Ma p lewood Creek Sediment Basin Reconstruction City of Renton, King County,WA F-1 2. Enclosed are maps and description of the proposed action and alternatives. Thank you in advance for your comments. If you have any questions, please call me at (206) 487-4698. Sincerely, " Stan J. Eccles Hazard Mitigation Officer Enclosure F-2 ' Maplewood Creek Sedimentation Basin Reconstruction City of Renton King County, Washington January 1995 The following is a more detailed description of the proposed project. This project involves reconstructing and improving the existing sedimentation basin on Maplewood Creek near the golf course. This reconstruction will nearly triple the size of the existing basin, creating a larger storage volume for sediment and debris, and trapping smaller particles. The existing access road running along the west side of the basin and creek will be improved by placing a gravel road surface. The upper concrete dam will be removed, along with the accumulated sediments, and the upper creek channel will be stabilized to reduce severe channel and bank erosion. The toe of the south bank at this dam is unstable and will be reinforced with riprap to prevent undermining after the dam is removed. A second section of the south bank, located just below the dam will also be reinforced with riprap. A diversion structure would be installed in the sedimentation basin to direct water to a future low flow fish passage channel that will be constructed through the golf course. More specifically, this project includes the following: 9 * Reconstruction and expansion of the existing lower retention basin, with an outflow weir to provide for fish passage. (The new basin will have a pool surface area of approximately 12,000 square feet and a volume of 1,300 cubic yards. It is expected to capture a larger portion of fine sand, and trap efficiency should increase from an existing 25% to 40 or 50%, or 500 to 600 cubic yards.) The pond and channel construction may involve up to 4,000 cubic yards of excavation and recompacted fill. * A rectangular bathtub overflow spillway; a 24 foot long by 12 foot wide reinforced concrete structure. It is estimated that the frequency of water flowing over the main spillway will be approximately 7 days per year on average, primarily during the winter high flow months. A concrete outlet pipe, 30 feet long and 72" in diameter will be connected to the spillway. Excessive hydraulic energy of the flows will be dissipated within the spillway, pipe and outlet structural system. * A fishway outlet on the west side of the sedimentation basin embankment. This will consist of two concrete weir structures connected by a 32 foot long by 42" diameter concrete pipe buried under the dam embankment. This fish F-3 ' ladder weir will be built with a slight reduction in hydraulic capacity to allow for excess water flow from the golf course during storm events. * A maintenance bypass pipe (300 foot long x 12" diameter), including a small inlet and gate structure, will be buried along the west side of the sedimentation basin and access road. This structure will divert low flows during the summer for sediment removal. * The existing access road along the west side of Maplewood Creek and the west embankment of the new sedimentation basin will be improved with a new surface of crushed rock. * Removal of a concrete dam that is part of an old obsolete holding pond, 500 feet upstream of the existing sedimentation basin and removal of accumulated sediments upstream behind this dam. The banks along this stretch, 60 feet from the dam, will be secured by rip-rap. These improvements will facilitate fish passage into the upper creek area. ,_ F-4 APPENDIX VII STATE OF WASHINGTON DEPARTMENT OF ECOLOGY ' Ms. Barbara Ritchie TEL: 206 ( ) 407-6922 WA Dept. of Ecology Environmental Review Section P.O. Box 47600 Lacey, WA 98504 M ,r. Tim D Acci TEL. (206) 407-6796 WA Dept. of Ecology Floodplain Management Section P.O. Box 47600 Lacey, WA 98504 Ms. Bernice Santee TEL: (206) 407-6923 EA Tracking Officer WA Dept. of Ecology P.O. Box 47703 Lacey, WA 98504-7703 OFFICE OF ARCHAEOLOGY AND HISTORIC PRESERVATION Dr. Robert G. Whitlam TEL: (206) 753-4405 WA Office of Archaeology and r; Historic Preservation 111 W. 21 Avenue Mail Stop: KL-11 Olympia, WA 98504 DEPARTMENT OF FISHERIES AND WILDLIFE Mr. Don Haring TEL: (206) 902-2528 Assistant Chief WA Dept. of Fisheries Habitat Management Division P.O. Box 43155 Olympia, WA 98504-3155 Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton, King County,WA G-1 Ms. Connie Iten TEL: (206) 753-3318 WA Dept. of Fish and Wildlife Habitat Division 600 Capitol Way N. Olympia, WA 98501-1091 DEPARTMENT OF NATURAL RESOURCES Mr. Dave Dietzman TEL: (206) 902-1634 WA Dept. of Natural Resources SEPA CENTER P.O. Box 47025 Olympia, WA 98504-7015 DEPARTMENT OF COMMUNITY DEVELOPMENT ' State Hazard Mitigation Officer TEL: (206) 923-4985 Attention: Marty Best WA Dept. of Community Development tEmergency Management Division P.O. Box 48346 Olympia, WA 98504-8346 DEPARTMENT OF TRANSPORTATION Ron Anderson, District Administrator WSDOT District 1 15325 S.E. 30th Place Bellevue, WA 98007 UNITED STATES GOVERNMENT U.S. ARMY CORPS OF ENGINEERS Karen Northrup, Chief TEL: (206) 764-3624 Environmental Resources FAX: (206) 764-3796 U.S. Army Corps of Engineers P.O. Box C-3755 Seattle, WA 98124-2255 Mr. Robert Newbill, P.E. TEL: (206) 764-3406 Emergency Management Branch FAX: (206) 764-3319 U.S. Army Corps of Engineers P.O. Box C-3755 Seattle, WA 98124-2255 ,A G2 Regulatory Branch U.S. Army Corps of Engineers P.O. Box C-3755 Seattle, WA 98124-2255 U.S. FISH AND WILDLIFE SERVICE Ms. Nancy G. Gloman TEL: (206) 753-9440 U.S. Department of Interior FAX: (206) 753-9008 Fish and Wildlife Service 3704 Griffin Lane S.E., Suite 102 Olympia, WA 98501 U.S. ENVIRONMENTAL PROTECTION AGENCY Jerold Opatz, Chief TEL: (206) 553-8505 Environmental Review Section FAX: (206) 553-1775 U.S. Environmental Protection Agency 1200 - 6th Avenue ' Mail Stop: WD 126 Seattle, WA 98101 DEPARTMENT OF COMMERCE ' Jacqueline Wyland, Division Chief Environmental and Technical Services National Marine Fisheries Service .. NOAA, Department of Commerce 525 N.E. Oregon Street, Suite 500 Portland, OR 97232 U.S. SOIL CONSERVATION SERVICE Mr. Lynn Brown TEL: -(509) 353 2337 State Conservationist FAX: (509) 353-2354 ' Soil Conservation Service West 316 Boone, Suite 450 Spokane, WA 99201-2348 ' G3 FEDERALLY RECOGNIZED TRIBES IN THE STATE OF WASHINGTON Chantal Stevens, Manager TEL: (206) 931-0652 Environmental Division Muckleshoot Indian Tribe 39015 - 172nd S.E. Auburn, WA 98002 ' KING COUNTY SURFACE WATER MANAGEMENT DIVISION Mr. Jim Cramer King County Surface Water Management 700 - 5th Avenue, Suite 2200 Seattle, WA 98104 CITY OF RENTON Renton Planning Department 200 Mill Street South Renton, WA 98055 Ronald Straka, Engineering Supervisor ' Public Works Department City of Renton 200 Mill Avenue South Renton, WA 98055 Daniel Carey, Civil Engineer Public Works Department City of Renton 200 Mill Avenue South Renton, WA 98055 �y G4 APPENDIX H COMMENTS RECEIVED AND OUR RESPONSES Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA A-1 2C67644470 CENPS-EN-PL Page 1 /2 Job 293 Feb-01 Wed 16:06 1995 ..�,,,. '. DEPARTMENT OF THE ARMY SFATTLE. OIS'IRIGT. CORPS OF ENGINEERS r.o. oox 375s .' SEATTLC. WASHINGTON 08124-2256 •roe ne.r.::r Planning Branch FEB I � r Stan Eccles ' Hazard Mitigation Officer, Region 10 130 - 228th Street Southwest Bothell, Washington 98021-9796 Dear Mr. Eccles: We have reviewed your letter of January 13, 1995 concerning _ work on Maplewood creek with respect to the U.S. Army Corps of Engineers' areas of special expertise and jurisdiction by law as designated by the President's council on Environmental Quality on December 21, 1984 . Pursuant to the Clean Water Act, a Section 404 permit may be required for this work. Section 404 applies to the placement of dredged or fill material in waters of the U.S. , including wetlands. To clarify jurisdiction and permitting requirements, a written inquiry should be made to the Seattle District, Regulatory Branch. iIn the future, we suggest better diagrams and a contour map be provided to facilitate review of fish passage conditions for projects of this type. We believe the project proposal would be improved if the following were considered: o Define project life and describe sediment removal, if any, during that life. Alternatively, will wetland plants be placed or encouraged to grow? �- o Describe species of fish and their seasonal , life stage, and use of the basin. ' o Ts there potential for wetland filtration of stormwater? o It isn't clear how close the road is to the creek, but it is best that it be out of the flood plain or more that 100 feet from the creek. . OPTIONAL CORM ny v :xl) FAX TRANSMITTAL •wp,y,;. io Hnm Dapl.i y J Plw�w/ d rug Far A------- NSN 7540 01 317 /U:H 56n i0i i;/NFHAL SEH\9CES ADNI•NKTnATI(IN S H_2 20t;Zb44470 GEN;PS-EN-PL Page 212 Job 293 Feb-01 Wed 16:o8 1995 —2— o Describe the amount of existing riparian vegetation or "buffer" and plans for planting mixtures of native woody species within 100 feet of the channel and any engineered portions of the ' project. The riparian zone has a number of biological functions Mat would improve the stream system. o Rather than just "hardening" the channel with riprap, use of bioengineering techniques would further improve the habitat. Please contact Fred Goetz or Jeff Laufle at (206) 764-3624 if you have questions or desire further information. Thank you for the opportunity to review this project. Sincerely, i Ka en S. Northup Chief, Environmental Resources section H-3 RESPONSES TO COMMENT LETTERS Response to letter from U.S. Corps of Engineers Environmental Resources Section ' * Define project life and describe sediment removal,if any, during that life? ' This project is designed to have a useful life of 50 to 100 years. Sediment accumulated in the basin will be removed every 1 to 2 years by the City, as now occurs with the existing basin. Normal maintenance of the basin will be done between June 15 and Sept. 15 to avoid potential ' impacts to fisheries resources. Sediment will be removed by construction equipment using an access ramp into the new basin. During sediment removal,water in the creek will be diverted around the basin in a pipe and will be discharged to the low flow fish bypass channel below the basin. Sedimentation basin efficiency is defined as the ratio of the quantity of deposited sediment ' to the total sediment inflow. This efficiency is dependent primarily on the sediment settling velocity and the flow velocity through the reservoir. Presently,the basin has an estimated trap efficiency of 25%(300 cubic yards). It is estimated that the expanded basin will have a trap efficiency of 40%to 50% or 500 to 600 cubic yards annually. In addition,the reconstructed basin is predicted to capture a larger portion of fine sand, with particles larger than about 0.1 mm captured during a 2-year flood event. *Will wetland plants be placed or encouraged to grow? Native shrubs and herbaceous species will be used to revegetate the construction area after construction of the new basin. The revegetation plan includes shrubs, sedges, and rushes adjacent to the new basin. See the body of the environmental assessment and Appendix B of the Harza Design Report for more detail on existing plant species within 100 feet of the channel and basin. * Describe species of fish and their seasonal,life stage, and use of the basin. There is a small population of resident trout in Maplewood Creek above the upper concrete dam and existing sedimentation basin. They may use the basin as part of their habitat but probably prefer the upper sections of the creek. It is difficult for migratory fish(salmon)to reach Maplewood Creek since they would have to travel up the 1,000 foot long 72-inch diameter culvert owned by the Washington State Department of Transportation. In addition, the upper concrete dam creates a barrier to fish passage into the upper reaches of Maplewood Creek. Resident trout have been observed in the creek, from the existing sediment pond upstream into the steeper canyon reaches. This section of the stream has been restocked by citizens a number of years ago with trout provided by the State Department of Game. See Appendix B of the Harza Report for more details. H-4 ' * Is there potential for wetland filtration of stormwater? There are no wetlands in the existing sedimentation basin to provide wetland filtration of stormwater. The proposed new basin is not designed to provide wetland filtration of stormwater. * How close is the road to the creek; is it out of the flood lain or more tha n an 100 feet from the creek? The existingaccess road is located ocated 10 to 20 feet west of the creek. It is located at the bottom of the ravine,which has steep slopes with medium to dense trees and bushes. The road must remain at this location for construction and long-term maintenance access. It is not located in a floodplain. Maple Valley Highway (SR 169)is a major arterial that run perpendicular to the lower reach of Maplewood Creek The creek passes under the Highway through a culvert just before it reaches the Cedar River. * Describe existing riparian vegetation or "buffer" and plans for planting mixtures of native woody species within 100 feet of the channel and any engineered portions of the project? Revegetation in the area of the sedimentation basin is planned. A variety of species will be placed to enhance the natural environment. For example, a selection of native shrub and herbaceous species will promote diversity in areas that are currently dominated by grasses and weedy forbs. Most existing vegetation along the lower reach of the creek, downstream of the sedimentation basin,will not be disturbed by the project. * Rather than just hardening the channel with riprap,use bioengineering techniques to further improve the habitat. Riprap is currently in place along the west bank of the creek upstream and downstream of the upper dam After the dam is removed, the riprap will be needed in those areas to keep the bank stable. The other areas where riprap will be placed involve eroding slopes that are currently at 1 to 1 or greater(horizontal to vertical). During final design, the City will review the use of riprap with the consulting engineer and consider using other biostabilization techniques where applicable. r-_ ' �wOIC UNITED STATES QEPARTNIEN7 OF COAAMERCE National Oceanic and Atmospheric Administration ' a NATIONAL MARINE•FISHERIES SERVICE ENVIRONMENTAL S TECHNICAL SERVICES DIVISION rr�res of�� 525 NE Oregon Street PORTLAND,OREGON 97232.2737 $03/230.5400 EAX 503/2305435 FEB 71995 FINW03 Mr. Stan Eccles ' Federal Emergency Management Agency Region X 130 228th Street,. Southwest Bothell, Washington 98021-9796 RE: Environmental Assessment for the -Maplewood Creek Sedimentation Basin Reconstruction Project -in Renton, Washington. Dear Mr. Eccles : Thank you for your January 13, 1995, letter requesting comments on a revised Environmental Assessment (EA) for the City of Renton' s Maplewood Creek sedimentation basin- reconstruction project. Our comments are based on the National Marine Fisheries Service' s (NMFS) responsibility for the protection and enhancement of anadromous fishery resources and their habitats. Maplewood Creek, a tributary of the 'Cedar River,' provides habitat for coho salmon (Oncorhynchus kisutch) 'and steelhead trout rI ) (Oncorhynchus mykiss) which are currently 'candidate species for U listing under the Endangered Species Act . Effects on these species may include inadequate :flows for spawning and rearing, cessation of •spawning if the fish reject the fish ladder, -delays in juvenile outmigration and adult upstream migration. The Cedar River also provides habitat for chinook salmon (Oncorhynchus tshawytscha) , sockeye salmon (Oncorhynchus nexka) and sea-run cutthroat trout (Oncorhynchus clarki clarki) which 2 are also candidate species. Downstream effects on these species may include decreased flows (until the low flow bypass channel is - constructed) , potential rapid increase of sediment and turbidity as a result of a failure of the sedimentation basin during a high flow event, a decrease in nutrients (overall productivity) , an increase in levels of pesticides and herbicides in the water (resulting from the low flow channel routing through the golf course) and changes in invertebrate populations due to changes in- the quantity and type of substrate... The information provided regarding the design details- was insufficient for our engineers to adequately address potential impacts from installation of the• sedimentation basin: Improper construction of fish ladders and low flow channels may result in H-G 2 . delaying upstream migration, the fish rejecting the ladder and ' either spawning below the structure or not .spawning if there is insufficient gravel, or stranding of juveniles. Identification of hydrologic. •and•.hydraulic parameters (such as range of flow, depths and velocities across the channel) are also necessitated.' This is critical, in that there- is proposed (ID armoring (riprap) of upstream areas that may divert the thalweg, resulting in .further erosion downstream. Riprap areas may also provide habitat fpr salmonid predators. NMFS recommends that a bioengineering solution be examined as an• alternative to riprap. ' These are issues that NMFS 'recommends be included in the RA for the project. NMFS remains willing to work• with the applicant to develop a system that will serve as a flood control structure yet provide for continued and improved salmonid usage of Maplewood Creek. • Quest•ions regarding this letter should be addressed to Ben Meyer of my staff at. (503) .230-5425. Sincerely, Tf->> �`; '► • ',-Jacqueline V. Wyland Division Chief H-7 ' Response to comment letter from National Marine Fisheries Service Environmental &Technical Services Division 1. Currently, it is difficult for migratory fish(salmon)to reach Maplewood Creek since they would have to travel up the approximately 1000 ft. long 72-inch diameter WSDOT culvert from the Cedar River. The outfall from this culvert is approximately 2 to 3 feet higher than the summer water levels in the river, and would only be accessible to fish during higher water levels in the ' river. Most of the Fisheries Service comments regarding possible impacts on current spawning in Maplewood Creek are not applicable since spawning currently does not, or very rarely, occur in Maplewood Creek due to the existing fish passage barriers. 2. Reconstruction of the existing sedimentation basin is not expected to have a negative effect on the Cedar River. The amount of flow from Maplewood Creek to the Cedar River will not decrease as a result of this project or the low flow fish passage channel project. The Fisheries Service comment suggesting that the new sedimentation basin would fail during high flows, causing increases in sediment and turbidity, is more applicable to the existing basin. The new sedimentation basin is designed with two times the sediment storage volume and three times the surface area of the existing basin. The new sedimentation basin will be more efficient at removing sediment and will trap smaller soil particles than the existing basin,which will reduce the sediment flow and turbidity in the Cedar River. The amount of beneficial nutrients reaching the Cedar River will not be decreased by the sedimentation basin project, and should be increased by the habitat improvements that result from removing the upper concrete dam and construction of the low flow fish passage channel. The existing channel through the golf course is relatively straight with predominantly short grass along the banks. The low flow fish passage channel will include new vegetation along the channel banks and will provide fish habitat on the golf course,where possible. The City will consider comments relating to the fishway during the environmental review of that project. The City does not expect that there will be an increase in the level of herbicides and pesticides reaching the Cedar River due to the construction of the low flow fish passage channel. The entire golf course is part of the Maplewood Drainage Basin and eventually drains to the Cedar River. The existing channel for Maplewood Creek already travels through the golf course and collects runoff from it. Runoff that would be collected by the low flow fish passage is already being collected by the existing channel and on-site drainage ditches, and eventually reaches the Cedar River. The golf course personnel follow the applicable state and federal regulations and manufacturer's instructions for applying herbicides and pesticides. The City utilizes best management practices when applying fertilizer, herbicides, and pesticides on the golf course to protect surface water and ground water quality. 3. The enlargement of the sedimentation basin will have no adverse impact on the immediate environment, since the existing pond will be expanded into a parking lot. The whole purpose of the separate fishway project is to encourage anadromous fish to begin to migrate up Maplewood i3-8 Creek. The Cityis i continual n ual coordination with WDFW to design a fishway that will meet this goal. The fishway is not a secondary goal of this project,but rather a separate project to create a successful new fishery in the creek. The design of the fish ladder from the Cedar River under SR 169 was reviewed and approved by the Washington State Department of Fish and Wildlife. It was constructed in the summer of 1994 by the Washington State Department of Transportation. The City's consultant discussed the sedimentation basin project with the Department of Fish and Wildlife (Ken Bates) and used a design similar to the fish ladder for the fishway outlet weir in the sedimentation basin. The City will review the proposed low flow fish passage channel with the Department of Fish and Wildlife to develop a design that will allow the best potential for fish passage. 4. Since the fishwayi of s not part this project, flows of the fishway are not detailed in the environmental assessment. As planning proceeds on the fishway,hydrologic parameters will be worked out. The fishway and now existing fish ladder are designed for a maximum now of 45 cfs, as approved by WDFW. A summary of the hydrologic analysis of the Maplewood Drainage basin is included in Section II-D of the Harza report. The distribution of design flows into the fishway outlet and main spillway is given in Section III, B and C. Riprap will be needed to retain parts of the bank upstream from the sedimentation basin, and to stabilize the eroding slope of the ravine adjacent to the concrete dam. Other more natural retention methods will be explored, such as logs and wood debris;however,there will probably be a need for riprap in some places where the bank is especially steep. The City will use enough riprap to ensure the stability of the slope. During final design,the City will review the use of riprap with the consulting engineer and consider using other biostabii ization techniques, where applicable. H-9 • �,ji,ITA7f j < x �yd IR?9 anY State of Washington DEPARTMENT OF FISH AND WILDLIFE Mailing Address: 600 Capitol Way N, Olympia, WA 98501-1091 -(206)902-2200;TDD(206) 902-2207 Main Office Location: Natural Resources Building, 1111 Washington Street SE,Olympia, WA - January 30, 1995 Stan Eccles Hazards Mitigation Officer Federal Emergency Management Agency 130 - 228th Street Southwest Bothell, Washington. 98021-9796 SUBJECT: Review and Comment - City of Renton Maplewood Creek Sedimentation Basin Reconstruction,. Maplewood Creek, Tributary to Cedar River, SW 1/4 of Section 15, -Township 23N, Range 05E, King -County, WRIA 08 . 0302 Dear Mr , Eccles : The Washington Department of Fish and Wildlife (WDFW) has- reviewed the above-referenced proposal and submits the following comments . Based on the limited plans which were reviewed, it appears that the project will provide improved protection for fish life compared to the present pond design. WDFW has been working with the City of Renton and the Washington Department of Transportation (WDOT) on a plan to resolve the current undesirable status of Maplewood Creek• on the golf course . �- The effects of urban development there have heavily impacted habitat in Maplewood Creek and severely reduced its fish production capacity. WDFW strongly supports the City of Renton in its efforts to improve the malfunctioning sedimentation pond and remove the associated fish passage barriers . WDFW hopes that an inclusive project will be constructed to acheive restoration of habitat in Maplewood Creek and connection of a new stream channel between the sedimentation pond and the fishway which the WDOT recently constructed under State Route 169 . The document reviewed was unclear as to the intent of the project, which indicated construction of a fish low flow channel in the cover letter and a "future fish passage low flow channel" in the project description. WDFW is very ( r uncomfortable with the labeling of this a "low flow channel" and with idea that this channel will be only for fish passage . The intent of this channel should be to provide the principle spawning and rearing habitat for salmon and steelhead in Maplewood Creek . Due to its location in the R E C EIV E E: basin and placement and impact of the sedimentation pond on F E B 1 1995 H-10 rr%tn n­n — ' Stan Eccles, FEMA Page 2 January 30, 1995 the creek (alteration of hydrology, hydraulics and sediment movement ) , fish production in Maplewood Creek could remain severely impaired by the impact of the golf course on the creek if this project is not carefully administered . Specific engineering comments concerning the project are : The high flow bypass channel should be converted to a closed pipe system so any juvenile or adult fish that enter it 2 during a flood are not trapped anywhere within the system when the flood recedes . WDFW has not reviewed the size or the capacity of the spillway ( Its design must be integrated with the design and capacity of the normal flow channel . ) . WDFW has not reviewed the fishway outlet design, dimensions, location, or capacity which are all referred to in the project description . These details will affect the success of fish passage_ It was mentioned that the fishway will be built with a reduction in capacity to allow surface runoff to enter the ^ channel . A design capacity of that channel has not been �i finally selected, however . A design flow of 40 cfs has been discussed . WDFW considers this to be a "target" flow, not a never-to-exceed flow. The effect of making it a never-to- exceed flow is that it may increase the diversion into the flood channel to an excessive frequency. WDFW could evaluate a never-to-exceed flow with additional data . Part of the issue in selection of the design flow is the capacity of the culverts under the highway downstream of the golf course . It is WDFW' s position that ponding of water on the golf course could occur during an extreme rainfall event . Removal of the concrete dam must include restoration of habitat in the area of the dam and resevoir as well as fish passage through the area . It must also preclude the risk of log jams forming on a narrow slot left by dam removal or of downstream channel degradation occurring that will result in a fish passage barrier at any remnant of the remaining structure . S i Stan Eccles, FEMA Page 3 January 30, 1995 WDFW expects to Continue discussions regarding this design with the City of Renton. These specific issues will Lr addressed further in that discussion, prior to issuance of a Hydraulic Project Approval for this project, which includes the sedimentation pond, the habitat channel, and the bypass flow pipe . Thank you for the opportunity to comment. If you have any questions or need additional information, please contact me ' at ( 206) 392-9159 . We appreciate your cooperation in our efforts to protect, perpetuate, and manage the fish resources of the state of Washington . Sincerely, i- &J, Larry Fisher Area Habitat Biologist Habitat Management Program if cc: Ted Mullet: Connie Iten Ken Bates Bruce Heiner �- H-12 Response to letter from State of Washington Department of Fish &Wildlife Habitat Management Program 1. The proposed project involves reconstruction of the existing sedimentation basin, the associated concrete structures in the basin, and removal of the upper concrete dam The low flow fish passage channel is separate from the FEMA Hazard Mitigation Grant for the sedimentation basin reconstruction. The City has started design work on the low flow fish passage channel to develop detailed plans and environmental information for that project. The City intends that the future flow fish passage channel project provide a way for migratory fish to gain access to the upper sections of Maplewood Creek and ravine for habitat and spawning purposes. The space on the golf course for the low flow fish passage channel is limited, and should not be considered as the principal spawning and rearing habitat in Maplewood Creek A balance between fish habitat and golf course space limitations will be established as part of the design of the fish passage channel. The City will review the low flow fish channel project with the Department of Fish and Wildlife and will apply for the required permits. The proposed flow distribution to the main spillway for Maplewood Creek and the low flow fish passage channel is limited by the capacity of the WSDOT fish ladder,the space available on the golf course for the low flow channel, and the range of flows that can be controlled by the proposed outlets in the sedimentation basin. WDFW has already approved the WDOT fish ladder which has a maximum flow of 45 �^ cfs;this ladder is already constructed and in place. A channel will be designed to allow for fish passage from the Cedar River to the ravine under a variety of flow conditions. More detailed study will be undertaken as the city approaches the design phase for the low flow fish passage channel. During this process,the city will continue to work closely with WDFW. The intent of the fishway project is not to build an elaborate fish habitat in the golf course proper,but to provide a passageway for fish to reach a more favorable,natural upstream habitat. However,the city intends to augment the habitat of the fishway as much as possible without undermining-the use of the golf course. This will involve planting appropriate riparian vegetation along portions of the channel. The weir to the fishway is 1 1/2 feet lower than the weir to the main channel. This differential will allow for the natural flow of the creek to pass through to the fish channel. The WDOT fish ladder is not sized for flows greater than 45 cfs and the height design of the weir to the fishway is consistent with this flow requirement. A flood flow is estimated to be 350 cfs and would be accommodated by the main channel. H-13 2. Converting the main channel to a closed pipe system is beyond the scope and funding of this project. The FEMA grant covers reconstruction of the sedimentation basin. No funding is available for this additional project. Also, it is uncertain whether, and to what extent, the presently designed system would actually cause fish entrapment. Therefore, the City has no plans or funding to replace the main channel of Maplewood Creek with a closed pipe system. The sedimentation basin reconstruction project and the low flow fish passage channel project do not require a pipe for the min channel. The proposed spillway for the sedimentation basin was designed to convey the peak flow from the 100-year design storm for future conditions(347 cfs). See Section HI of the design report. 3. The 45 cfs design flow of the fishway and the WDOT fish ladder was determined at as a result of close cooperation between the City,WDFW, and the consultant. Ken Bates of WDFW has been involved with this project since spring of 1992. 4. According to the City, log jams at the proposed opening of the upper concrete dam are not likely. This opening will be 10 feet wide at an elevation of 1-foot below stream grade. From the bottom of the opening,the sides will slope outward at a 45 degree angle, enlarging the opening by 2 feet for every vertical rise of 1 foot. If the concrete dam does not extend beyond the proposed opening, or is unstable, the entire dam may be removed. Regular City maintenance of the sedimentation basin can include checking the upper dam area for debris blockages and channel damage that could preclude fish passage. Habitat restoration includes stabilizing areas of potential soil failure around the upper dam with riprap, or other acceptable biostabilization methods. Boulders can be placed in the stream for habitat enhancement, as suggested by the Washington State Department of Fish and Wildlife. Areas affected by construction will be revegetated with native plant species. 5. The city will continue to work with the WDFW and the consultant throughout this project and into the fishway project. The city plans to start the permitting process for both projects in late spring of this year. H-14 �.^•. United States Natural Rode Pointe Tower 11,Suite 450 Department of Resources W.316 Boone Avenue Agriculture Conservation Spokane,WA99201-2348 Service February 21, 1995 Stan Eccles, Hazard Mitigation Officer Federal Emergency Management Agency 130 228th Street Southwest Bothell, WA 98021-9796 Dear Mr. Eccles: We appreciate the opportunity to review the Maplewood Golf Course Project for the City of Renton. This project will not impact any planned or existing work by the Natural Resources Conservation Service (formerly the SCS) . The King Conservation District and/or the Urban Resources Assistance Team of the Natural Resources Conservation Service can assist the City of Renton for the development of an erosion control plan to control sedimentation during construction. Their addrLsss is: Technical Center Building #19 35 Powell Avenue S.W. Renton, WA 98055-4262 Sincerely, ail. ,. LYNN A. BROWN State Conservationist cc: `Joe Henry, NRCS, Renton, WA. RECEIVED F E B 2 4 1995 FEMA-REGION X The Nawral Resources Conservator,service. formerly the soa Conservation Service, Is an agency of the United States DepannentofAgriaduxe AN EQUAL OPPORTUNITY EMPLOYER 1"" H-15 King Countv Surface'Water Management Division Department of Public Works 700 Fifth Avenue Suite 2200 Seattle,WA 98104 (206)296-6519 (206)296-0192 FAX February 6, 1995 Stan J. Eccles, Hazard Mitigation Officer Federal Emergency Management Agercy-(FEMA) . Region X 130 - 228th Street Southwest Bothell, WA 98021-9796 Dear Mr. Eccles: This letter is in response to your January 13, 1995, letter regarding the City of Renton's proposal to enhance the sedimentation basins located in Maplewood Creek. As your letter notes, this proposal is similar to one submitted for our review in August of 1992. ' The City of Renton and the King County Surface Water Management (SWM) Division are active members of the Watershed Management Committee for the Cedar River Basin and Nonpoint Pollution Action Plan (Basin Plan). The public draft of the Basin Plan is due for release in the next few weeks. It makes the following recommendation regarding the Maplewood sedimentation basins: �- The City of Renton should replace the two existing sediment ponds on Tributary 0302 with one designed to allow upstream fish passage at RM 0.35 and stabilize the eroding banks of the stream above the pond with large woody debris. In addition, the City should consider enhancement of habitat in the reach that passes through the golf course to facilitate upstream fish passage and provide rearing and spawning habitat." ' SWM Division and Cityof Renton staff have discussed scussed the proposed action during the preparation.of the Basin Plan. As we stated in our August 11, 1992 letter to FEMA commenting on Renton's earlier application, the SWM Division basically supports the City's proposal. However, we would like to make some suggestions that we believe would improve the project. First the SWM Division has fo und that sediment balms such as the structure proposed in © this summary have a limited ability to remove medium to fine sediment from streams, and that they require constant maintenance. It is preferable to control sediment by reducing upstream erosion rather than by intercepting the material downstream. To the extent possible, upstream flow reduction should be encouraged in addition to the proposed project. RECEIVED FEB 10 1995 H-1 G FEMA-REGt0N X Stan J. Eccles February 6, 1995 Page 2 Second, any design requiring excavation in the highly erodible soils of the Maplewood Creek ravine should include careful attention to bed stabilization. Some form of gradient control treatment should be included at the upstream end of the proposed sediment pond to prevent the formation of a knickpoint and progressive incision of the stream bed. Third, the proposal summary states that after the dam and its impounded sediment are removed the upper creek channel will be stabilized and two areas of the bank will be reinforced with riprap. The SWM Division recommends the use of "bioengineering" 33 techniques incorporating vegetation, timbers, and natural fabrics in place of riprap alone wherever possible. These methods, many of which are presented in King County's Guidelines for Bank Stabilization Projects, can help control erosion for relatively low cost while preserving a riparian environment that meets the spawning and rearing needs of fish and is more suitable for human recreation. Our final and most serious concern centers on the proposed low flow diversion structure. Our experience in nearby Madsen Creek has shown that this kind of device can have the effect of sorting the sediment entering the pond, impounding coarse sediment while allowing the finer materials into the low flow channel. When large, flushing flows are prevented from entering the low flow channel, the fine sediment tends to settle and form a tight matrix with the larger material on the channel bottom. This cemented condition can _ seriously hinder fish spawning activity and egg survival. We suggest designing the flow diversion structure so that the high flow channel becomes active only during relatively large events, beginning at about the 10-year discharge, for example. Thank you for the opportunity to comment on this document. If you have questions, please call Keith Hinman, Basin Planning Program Manager, at 296-8053 or Glenn Evans, Cedar River Basin Plan Senior Engineer, at 296-8386. g Sincerely, Jim Kramer IL Manager �..;' JK:gmc7 cc: Ken Guy, Assistant Manager, Surface Water Management Division Dave Clark, Manager, River Management Section Keith Hinman, Manager, Basin Planning Program ATTN: Roz Glasser, Project Manager, Cedar River Basin Plan Glenn Evans, P.E., Senior Engineer H-17 Response to Comment Letter by King County Surface Water Management 1. Upstream flow control and erosion reduction would involve additional projects by the City and/or the County to detain flow from already developed areas above the Maplewood Creek ravine and release it at a lower flow rate. These types of projects could help reduce the erosion occurring in the ravine. However, they would require more land, design and construction costs, and would take more time to implement than the sedimentation basin project. In addition, the soils in the ravine are highly erodible (as stated in the design report) and the reconstructed sediment basin would still be needed to capture sediment and debris from the ravine, even with the implementation of upstream projects. 2. The City and it's consultant were aware of the August 11 1992 letter from Kin gu g County Surface Water Management, and addressed those concerns in the project design. The project will minimise the disturbance of the creek bed near the upper concrete dam, provide slope stabilization where potential slope failure may occur, and will allow the stream bed to stabilize at its' existing slope after the upper dam is removed. Gradient control was provided by setting the water level in the pond to the elevation of the upper end of the pond during flow through the fishway weir. Additional protection could be provided by lowering the elevation of the upper end of the pond, or by stabilizing the upper end with larger cobbles and rocks. The City and it's consultant will review these features during the final design and make any revisions necessary to address possible erosion of the streambed upstream of the sedimentation basin. 3. During final design, the City will review the use of riprap with the consulting engineer and consider using other bio stabilization techniques,where feasible. 4. The design of the proposed low flow fish passage channel and control structure is different �- from the project on Madsen Creek. The weir for the fish channel is 1.5 feet lower than passage the weir for the main channel, and will allow flows from 0 to 17 cfs into the fish passage channel before flow goes into the main channel. Flow into the fish passage channel will continue to increase up to 45 cfs for the 100-year design storm The range of flow will provide some flushing action for the fish passage channeL During the fish passage channel design,the City's consultant will analyze the potential for sediment transport and deposition and can minimise the potential for sediment deposition in the fish passage channel. The 10-year flow for Maplewood Creek, using the HEC-1 model results, is 200 cfs for existing conditions. The WSDOT fish ladder has a hydraulic capacity of approximately 45 cfs, and was not designed for a 10-year flow. Also, the golf course would not be able to dedicate the space needed for a channel that could accommodate the 10-year flow. H-18 STATt. o � n s 02 O �y'� 1a89 a STATE OF WASHINGTON DEPARTMENT OF COMMUNITY, TRADE AND ECONOMIC DEVELOPMENT OFFICE OF ARCHAEOLOGY AND HISTORIC PRESERVATION 111 21st Avenue S.W. P.O.Box 48343 Olympia, Washington 98504-8343 (206)753-4011 SCAN 234-4011 January 26, 1995 Mr. Stan J. Eccles Hazard Mitigation Officer Federal Emergency Management Agency Region X 130 228th Street Southwest Bothell, Washington 98021-9796 Log: 011995-08-FENIA Re: Renton Flood Hazard Mitigation Dear Mr. Eccles: Thank you for contacting the Washington State Office of Archaeology and Historic Preservation (OAHP) regarding the above referenced action. From your letter, I understand that the Federal Emergency Management Agency (FEMA) proposes to undertake flood hazard mitigation measures proposed by the City of Renton. In response, it is my opinion that the proposed action will have no effect upon properties• presently listed in the National Register of Historic Places. However, we do recommend that the revised Environmental Assessment assess the eligibility of the existing concrete dam for listing in the National Register. The dam should be evaluated for eligibility as part of the assessment as the proposal is for removal of this structure. Thank you for the opportunity to comment. Should you have any questions, please feel free to contact me at (360) 753-9116. Sincerely, Grego riffith Compr ensive Planning Specialist GG:ts RCI'lE€� J A N 2 7 1995 H-19 FLMA-RE0!0;;G;( It-10 Response to the Washington State Historic Preservation Office The City has reviewed the eligibility criteria of the Washington State Historic Preservation Office and City records to establish any historical significance of the old concrete dam, upstream of the sedimentation basin, built in the 1920's for irrigation control. The conclusion is that this structure does not meet this criteria. It is a simple concrete structure with no distinguishing marks. It shows signs of age; parts have broken off. According to Dan Carey, Civil Engineer with the City of Renton, this structure is not a unique engineering structure and is not one-of-a-kind. i t.. I . 1 �. H-20 c: 1: CITY OF I2ENTON Planning/Building/Public Works Department Earl Clymer,Mayor Gregg Zimmerman P.E.,Administrator February 3, 1995 Stan Eccles, Hazard Mitigation Officer Federal Emergency Management Agency - Region X 130 228th Street SW Bothell, WA 98021-9796 SUBJECT: COMMENTS ON THE MAPLEWOOD CREEK SEDIMENTATION BASIN RECONSTRUCTION FLOOD HAZARD MITIGATION PROPOSAL Dear Mr. Eccles: �i The City of Renton Surface Water Utility strongly supports the proposed Maplewood Creek Sedimentation Basin Reconstruction project. We developed the project to address the flooding that occurred on the. Maplewood Golf Course in January 1990, and have included other factors that give the project multiple benefits. The primary purpose of the project is to enlarge the existing sedimentation basin and increase its sediment and debris trapping efficiency. This will reduce the amount of sediment that is deposited in the channel on the golf course, and the potential for flooding during high flow events. By reducing the potential for flooding, the project �- protects the golf course, the City water supply wells and treatment building.on the golf course, and the private residences on the south side of SR-169. A secondary benefit of the project includes the reduction of the amount of sediment transported to the Cedar River. This will help reduce the effect of sedimentation of spawning gravels in the Cedar River and will improve surface water quality by reducing turbidity. The old concrete dam and accumulated sediments upstream of the existing ' sedimentation basin will be removed. This will have a potential benefit b allowing 9 fish passage into the upper reaches of Maplewood Creek. Two areas of unstable slopes near the old dam will be stabilized. This will help to reduce the erosion in the canyon and the amount of sediment being deposited in Maplewood Creek. The plans for the reconstructed sedimentation basin include a fishway outlet on the west side of the basin. The fishway outlet will be connected with a low flow fish passage channel that the City will construct across the golf course. The low flow fish passage channel and fishway outlet Will allow salmon to migrate from the Cedar River into the upper reaches of Maplewood Creek. This is a separately funded project that is being constructed by the City as part of an agreement between the State Department of Fisheries, the State Department of Transportation, and the City. T H-21 FE B 6 1005 200 Mill Avenue South - Renton, Washington 98055 FEMA-P,EGI6FJ X Stan Eccles, FEMA Maplewood Creek Sedimentation Basin Reconstruction Flood Hazard Mitigation Proposal Page 2 Department of Transportation has completed construction of the fish ladder from the Cedar River to the Maplewood golf course. We are currently working with the King County Surface Water Management Division to develop the Cedar River Basin Plan. The Preliminary Draft Cedar River Basin Plan recommends the construction of this project and identifies other upstream improvements intended to reduce erosion within the Maplewood Creek ravine over time. The Maplewood Creek Sedimentation Basin Reconstruction Project is a much needed improvement, since the erosion problem will continue indefinitely even .with the upstream improvements. We feel that the project will have a positive effect on the human and natural environment and are hopeful that the remaining.-grant.funding-for the project will be. approved by FEMA. We are proceeding with design plans for the low flow fish passage channel, and have appropriated the necessary matching funds for the reconstruction of the sedimentation basin. If you have any questions, please call me at (206) 277-5548 or Daniel Carey at (206) 277-6193. Sincerely, Aw) 464a- Ronald J. Straka, P.E., Utility Engineering Supervisor Surface Water Utility H:DOCS:95-1O9:DWC:ps CC: Gregg Zimmerman Sam Chastain Ron Olsen ' Dan Carey IL H-22 1 APPENDIX I-PHONE LOG Maplewood Creek Sedimentation Basin Reconstruction iNAME DATE PHONE FEMA COMMENT Glen Evans 8/25/92 CF Information on systems. Dan Carey 12/28/94 (206) JM Further information. 277-6193 Ron Straka 1/5/95 (206) JM Site visit at Maplewood Creek. Dan Carey 277-5548 HH Dan Carey 1/13/95 (206) JM Further information. 277-6193 Dennis Carlson 1/31/95 (206) JM Request response to LOI. USFWS 753-9440 Robt.Whitlam 1/31/95 (206) JM Request response to LOI. Do HP 753-4405 avid Van Vijn 2/1/95 (206) JM Request response to LOI. USACE 764-3624 Dan Carey 2/21/95 (206) JM Further information for LOI comments. 277-6193 i s Environmental Assessment-Maplewood Creek Sediment Basin Reconstruction City of Renton,King County,WA I-1 APPENDIX J ATE: 03/13/90 TtME: 12:50PM FEDERAL EMERGENCY MANAGEMENT AGENCY P.2 - PROJECT APPLICATION SUMMARY DISASTER #: 0852 ID: 033-57745 APPLICANT: RENTON PLEMENT NO.: 1 PROJECT APPROVED # CAT COMPL DATE OSR AMOUNT ----- PROJECT DESCRIPTION '5 15 A 02/07/90 $41,519.00 ---_--__ PROJECT TITLE: DEBRIS REMOVAL DAMAGE FACILITY: CITY STREETS AND GOLF COURSE - KING COUNTY PUBLIC DAMAGE LOCATION: CITY WIDE LOCATIONS WORKS ! DAMAGE DESC: CLEARANCE OF WRECKAGE AND DEBRIS f OTHER PROPERTIES. FROM PUBLICALLY OWNED STREETS AND f CLEANOUT OF CATCH BASINS AND DRAINAGE FACILITIES AT: A DSRS) THAT CONSTITUTES A THREAT TO LIFE AND PUBLIC SAFETY. ( 1 ---- $41,519.00 ELIGIBLE $31,139.00 75 % FEDERAL SHARE !`' a 02/07/90 $25,921.00 PROJECT TITLE: EMERGENCY PROTECTIVE MEASURES DAMAGE FACILITY: CITY OWNED STREETS AND OTHER PUBLIC PROPERTY DAMAGE LOCATION: VARIOUS LOCATIONS - CITY WIDE DAMAGE DESC: EMERGENCY PROTECTIVE MEASURES TO PREVENT DAMAGE TO IMPROVED PROPERTY ! IN THE PUBLIC INTEREST. y REMOVAL OF HEALTH AND SAFETY HAZARDS WAS OF PRIMARY CONCERN. WORK CONSISTED OF AIDING AND PROTECTING CITIZENS, SANDBAGGING, EMERGENCY REPAIRS OF ROAD SHOULDERS, BRIDGE AND DRAINAGE FACILITIES. B ( 1 DSRS) $25,921.00 ELIGIBLE ! $19,441.00 75 % FEDERAL SHARE ! Environmental Assessment-Maplewood Cre ek Sediment Basin Reconstruction City of Renton, King County, WA J-1