Construction in the Floodplain Spring 2011 NMFS/FEMA WorkshopsDeeAnn Kirkpatrick 3 Case Studies 1. New Development (outside Protected Area)2. Redevelopment (outside Protected Area)3. Redevelopment with greater than 10% increase in footprint (inside Protected Area) General Steps in Making Effects Determinations 1. Review Background/Project Description 2. Analyze Effects (direct, indirect, cumulative) 3. Evaluate BMPs/Mitigation 4. Make Effects Determination General Effects Analysis Determine what habitat features and functions will be affected by the project compared to the environmental baselineConsider duration, timing, severity, proximity, etc. of effects Evaluate BMPS/Mitigation Measures Consider available options to avoid, rectify, compensate the loss and evaluate the effectiveness of each Case Study 1 Background Information • Project Area –upper floodplain of large river • Habitat Conditions –(environmental baseline) disturbed pioneer vegetation species on site, forested off site • Presence of listed species (including timing and life stage) -steelhead and Chinook Case Study 1 -Project Location Legend:CZM –Orange100-year Floodplain-light blueParcel Boundary –BeigeStreams –dark blueHouse location -* * Case Study 1 Project Description • Infrastructure -house, yard, driveway, patio, 2,700 ft2 • Pin construction • Grading 700 ft2 (driveway, patio) • Clearing –3000ft2of grasses & blackberry,aldersgrasses Case Study 1 -Analyze Effects, Evaluate BMPs Flood Storage and Fish Habitat • No flood storage removed • Project removed 3,000ft2fish habitat • Project created greater area of fish habitat, planting 6,000 ft2 of diverse vegetation on site Case Study 1 -Analyze Effects, Evaluate BMPs Stormwater–LID • Pin construction • Rain Garden Case Study 1 -Analyze Effects, Evaluate BMPS O:\MyFiles\Pictures\MVC-005F.JPG Stormwater-Collecting and dispersing roof-top runoff to rain barrel and rain gardenDispersing runoff from driveway and patio to porous pavers Analyze Effects and Evaluate BMPs (cont.) Vegetation – Replaced function by providing 2x cleared area, Added plant diversity E:\skagit habitat.JPG Analyze Effects and Evaluate BMPs (cont.) Bank Stability –No bank stabilization needed to protect house located away from river channel and direct flow path Analyze Effects and Evaluate BMPs (cont.) Channel Migration –house sited outside of identified CMZ skagit.jpg Analyze Effects and Evaluate BMPs (cont.) Hyporheic Zone –Surface, groundwater and hyporheic zone flow exchange main-tained due to pin construction and sw infiltration measures http://www.nap.edu/books/0309082951/xhtml/images/p2000a440g34001.jpg Analyze Effects and Evaluate BMPs (cont.) Wetlands–No wetlands affected on site B1 Analyze Effects and Evaluate BMPs (cont.) Large Wood –5 pieces of wood removed from buildingsiteReplaced on site in lower floodplain O:\MyFiles\Pictures\wood in floodplain.jpg Case Study 1 Summary Effects:Clearing 3000 ft2Rooftop runoff 2000 ft2Grading 700 ft2(driveway, patio) Hyporheic ZoneLarge wood –5 piecesBank stability, CMZ, WL BMPs/Mitigation:6000 ft2planted fish habitat all infiltratedall infiltratedinfiltrated under house Replaced on siteNo change Case Study 1 -Effects Determination NE –No Effect NLAA –Not Likely to Adversely Affect LAA –Likely to Adversely Affect Your choice??? Case Study 1 Effects Determination Coho resize 1 NLAA –Not Likely to Adversely Affect Case Study 2 : Redevelopment Outside the protected area, in the floodplain Case Study 2Project Location Legend:CZM –Orange100-year Floodplain-light blueParcel Boundary –BeigeStreams –dark blueHouse location -* * Case Study 2 Background Information • Project Area –upper floodplain of small river • Habitat Conditions –cleared except for 300 ft2wetland, disturbed vegetation off site • Fish presence –steelhead and Chinook Case Study 2 Project Description • House addition -1,350 ft2 in upper floodplain on fill • Clearing -already cleared except 300 ft2wetland • Fill –150 yds3placed to elevate addition and fill 300 ft2wetland • Grading 1,400 ft2 • No BMPs or mitigation measures Case Study 2 Analyze Effects • Flood Storage and Fish Habitat –lost 1700 ft2/150 yd3 • Stormwater –untreated/uncontrolled from 1350 ft2 • Vegetation –removed 300 ft2 • Wetlands –filled 300 ft2 • Hyporheic zone –no infiltration provided • Bank Stability –no change • Channel Migration –no change • Large Wood –no change Case Study 2 Effects and BMP Summary Effects: Wetland & House fill 150 yd3 C &G (300 ft2 +1400 ft2) Roof runoff Hyporheic Zone Bank stability CMZ LW BMPs/Mitigation:NoneNone NoneNoneNo ChangeNo ChangeNo Change Case Study 2 Effects Determination NE –No EffectNLAA –Not Likely to Adversely AffectLAA –Likely to Adversely Affect Case Study 2 Effects Determination Coho resize 1 LAA –Likely to Adversely Affect Case Study 2A Analyze Effects, Evaluate BMPs Flood Storage and Fish Habitat • Project created 1,700 ft2(150 yds3) of combined floodplain storage and created wetland on site (lower floodplain) • Project created enhanced area of fish habitat by planting 1,700ft2in the floodplain/wetland storage area Case Study 2A -Analyze Effects, Evaluate BMPs Stormwater–Used LID Collecting and dispersing roof-top runoff to rain garden and new wetland area Analyze Effects and Evaluate BMPs (cont.) Vegetation –Enhanced function by planting largergraded area, increasing plant diversity E:\skagit habitat.JPG Analyze Effects and Evaluate BMPs (cont.) Bank Stability –No bank stabilization needed as structure was sited away from channeland flow path Analyze Effects and Evaluate BMPs (cont.) Channel Migration –house sited outside identified CMZ skagit.jpg Analyze Effects and Evaluate BMPs (cont.) Hyporheic Zone –Surface, groundwater, and hyporheic zone exchange maintaineddue to rain garden, wetland & vegetated flood storage area http://www.nap.edu/books/0309082951/xhtml/images/p2000a440g34001.jpg Analyze Effects and Evaluate BMPs (cont.) Wetlands–300 ft2disturbed reed canary grass wetland replaced with 1,700 ft2shrub/meadow wetland/storage area upper_beaver_dam6 Analyze Effects and Evaluate BMPs (cont.) Large Wood –No large wood in floodplain. What WD should look like Case Study 2A Summary Effects:WL/house fill 150 yd3 C &G (300 ft2 +1400 ft2) Roof runoffHyporheic ZoneBank stability, CMZ, LW BMPs/Mitigation:Excavated 150 yd3 1700 ft2planted fish habitat floodplainstorage/wetland fish habitat (lower FP)Infiltrated via RG/wetlandInfiltration maintainedNo change Case Study 2 Effects Determination NE –No EffectNLAA –Not Likely to Adversely AffectLAA –Likely to Adversely Affect Case Study 2A Effects Determination Coho resize 1 NLAA –Not Likely to Adversely Affect Case Study 3: Redevelopment > 10% increase in footprint Inside the Protected Area, in the lower floodplain, in the Riparian Buffer Case Study 3 -Project Location Legend:CZM –Orange100-year Floodplain-light blueParcel Boundary –BeigeStreams –dark blueHouse location -*Riparian buffer -green * Case Study 3 Background Information • Project Area –lower floodplain of large river • Habitat Conditions –non-native landscaping. Developed conditions off site. • Fish presence –Chinook and steelhead Case Study 3Project Description • Infrastructure –350ft2addition • Clearing -400 ft2 grass and landscaping • No fill –structure elevated on pilings. Case Study 3 -Analyze Effects, Evaluate BMPs Flood Storage and Fish Habitat • No flood storage removed (350 ft2addition on pilings) • Project removed 400 ft2 of potential floodplain fish habitat • 400 ft2enhanced floodplain habitat provided Case Study 3 -Analyze Effects, Evaluate BMPs Stormwater–Used LID Collecting and dispersing roof runoff to rain garden Analyze Effects and Evaluate BMPs (cont.) Vegetation –Provided 400 ft2improved vegetation function in riparian buffer E:\skagit habitat.JPG Analyze Effects and Evaluate BMPs (cont.) Bank Stability –No bank stabilization needed Analyze Effects and Evaluate BMPs (cont.) Channel Migration –house sited in riparian buffer portion of the Protected Area but outside of identified CMZ skagit.jpg Analyze Effects and Evaluate BMPs (cont.) Hyporheic Zone –Maintain flow between surface, groundwater and hyporheic zone dueto rain garden, planted area, and infiltration under house. http://www.nap.edu/books/0309082951/xhtml/images/p2000a440g34001.jpg Analyze Effects and Evaluate BMPs (cont.) Wetlands–No wetlands affected on site upper_beaver_dam6 Analyze Effects and Evaluate BMPs (cont.) Large Wood –no wood in or removed from flood-plain slide0087_image034 Case Study 3 Summary Effects:House expansion -350 ft2 Clearing -400 ft2Roof runoffHyporheic ZoneBank stability, CMZ, LW,WL BMPs/Mitigation:350 ft2 on pilings400 ft2 planted fish habitat, flood storage in bufferinfiltrated via rain gardenrain garden, planted area, infiltration under house no change Case Study 2 Effects Determination NE –No EffectNLAA –Not Likely to Adversely AffectLAA –Likely to Adversely Affect Case Study 3 Effects Determination Coho resize 1 NLAA –Not Likely to Adversely Affect Case Study 4: Redevelopment > 10% increase in footprint In the Riparian Bufferof the Puget Sound marine shoreline Case Study 4 Background Information • Project Area –marine shoreline of Puget Sound • Habitat Conditions –non-native landscaping. Mixed native vegetation and developed conditions off site. • Fish presence –Chinook, steelhead summer chum, and forage fish Case Study 4Project Description • Infrastructure –350ft2addition • Clearing -400 ft2 grass and landscaping • No fill –structure elevated on pilings. Case Study 4 -Analyze Effects, Evaluate BMPs Flood Storage and Fish Habitat • 350 ft2addition on pilings, no effect on flood storage • No aquatic fish habitat in floodplain e.g., saltwater lagoons Case Study 4 -Analyze Effects, Evaluate BMPs Stormwater–Used LID Collecting and dispersing roof runoff to created native vegetation area Analyze Effects and Evaluate BMPs (cont.) Vegetation –Provided 400 ft2improved vegetation function in riparian buffer Analyze Effects and Evaluate BMPs (cont.) Shoreline Armoring – None needed Analyze Effects and Evaluate BMPs (cont.) Longshoresedimenttransport –house sited in riparian buffer of shore-line but above beach sediment processes Sediment transport Analyze Effects and Evaluate BMPs (cont.) Groundwater –Maintain flow between surface and ground-water due to created native vegetation planted area, and infiltration under house. Analyze Effects and Evaluate BMPs (cont.) Wetlands–No wetlands affected on site upper_beaver_dam6 Analyze Effects and Evaluate BMPs (cont.) Large Wood –no wood in or removed from shoreline/riparian buffer Case Study 4 Summary Effects:House expansion -350 ft2 Clearing -400 ft2Roof runoffGroundwater RechargeBank stability, LST, LW,WL BMPs/Mitigation:350 ft2 on pilings400 ft2 planted native vegetation in bufferinfiltrated in vegetated areaplanted area, infiltration under house no change Case Study 4 Effects Determination NE –No EffectNLAA –Not Likely to Adversely AffectLAA –Likely to Adversely Affect Case Study 4 Effects Determination Coho resize 1 NLAA –Not Likely to Adversely Affect Questions? skagit.jpg