Making Effects Determinationsfor development in the floodplain What Standard is Required? What Effects Standard is required depends on where your project is located In the Protected Area the standard is: “No Adverse Effect -No Mitigation except Avoidance” In the remainder of the floodplain, the standard is: “Mitigate the Adverse Effects of Floodplain Development” The protected area, and the rest of the floodplain HellFarSideIcon_300.gif The “Effects Spectrum” No Effect . Not Likely To Adversely Affect entirely beneficial effects (eg, levee setback when original levee is not at OHWM) insignificant effects (effects ephemeral, e.g. removing a blocking culvert when fish are not present in the stream) discountable effects (effects extremely unlikely, e.g. removing blocking culvert when the stream is completely dry) . The “Effects Spectrum” cont. Likely To Adversely Affect adverse effects with significant intensity (e.g.impactpile driving noise that injures juveniles) or duration (e.g. riprap bank armoring harms juveniles the entire time it is there) . Jeopardy when an action harms, injures, or kills individual fish, there may be sufficient numbers affected(at one time, or over time), to change the population’s demographics–which we call viability parameters (abundance, productivity, spatial structure, or diversity). If a Population is weakened to the point that it may be extirpated, it increases the likelihood of jeopardy to the species (ESU or DPS) because that loss alters the viability parameters of the species. • The effects determination is heavily influenced by conditions present in the environmental baseline • Habitat features must exist before they can be adversely affected • The same action conducted in different landscape conditions can have different effects determinations The “Effects Spectrum” cont. Multiple factors influence where on the Effects Spectrum a given project will land 1) What features of habitat are there? What features of habitat are there? tolt floodplain.jpg Riparian vegetation, floodplain access/refugia, suitable gravels for spawning, forage, hyphoreicrecharge/base flows, channel forming process/establishment of channel complexity, large woody debris ToltRiver & Floodplain What features of habitat are there? chehalis-flood-12607-003.jpg Flood storage, some low quality refuge, some groundwater recharge. Chehalis River & Floodplain What features of habitat are there? Multiple factors influence where on the Effects Spectrum a given project will land 1) What features of habitat are there? 2) What purposes/functions do they serve? What purposes/functions do they serve? Fortson-Re-connect-sidechannel.jpg Side channel spawning and rearing, forage, cover ForstonCr. floodplain refuge.jpg Flood refuge for freshwater-rearing juveniles, and forage What purposes/functions do they serve? Multiple factors influence where on the Effects Spectrum a given project will land 1) What features of habitat are there? 2) What purposes/functions do they serve? 3) How well and how often ? How well are the functions served? skagit-river-95-flood_med.jpg Skagit River 1995 flood seattle flood.jpg Flooding in Seattle How well are the functions served? How often are the functions utilized? magfreq.jpg The 5-year floodplain has a 20% chance of being inundated /accessed by fish) in any given year. The 100-year floodplain has a 1% chance of being inundated/accessed by fish in any given year. 1) What features of habitat are there? 2) What purposes/functions do they serve? 3) How well and how often ? 4) What habitat features will the project impact? Multiple factors influence where on the Effects Spectrum a given project will land Floodplain development on Yakima River 2_Page_10_Image_0001.jpg Development proposed for floodwayand floodplainareas. Impacts to: floodplain refuge, forage, riparian vegetation, cover, water quality, groundwater recharge, stream velocity, side channel formation, floodplain connectivity. (Yakima River). What habitat features will the project impact? 1) What features of habitat are there? 2) What purposes/functions do they serve? 3) How well and how often ? 4) What habitat features will the project impact? 5) Will the impacts coincide with fish presence? Multiple factors influence where on the Effects Spectrum a given project will land Will impacts coincide with fish presence? fish seining.jpg Work in the dry. Construction impacts will not overlap with fish presence. naches OpeningChannel510op.jpg Naches River bank repair. Construction impacts (noise, turbidity, placement of rock in aquatic habitat) overlap with fish presence. Also riparian vegetation /cover impacts, forage reduction, hydrology and channel process impacts. Will impacts coincide with fish presence? emergencyKatrina6.jpg Katrina Response –this is so obviously wrong -we’d neverdo this here…. Will the impacts coincide with fish presence? Floodplain development on Yakima River 2_Page_02_Image_0002.jpg Construction impacts will not, but impacts to flood refugia, water quality, floodplain connectivity, natural bank conditions and groundwater recharge, and channel complexity will coincide with fish presence, when the water rises. Will the impacts coincide with fish presence? Impacts and Fish Presence Steps that keep habitat impacts from overlapping with fish presence are “avoidance measures” e.g: working when fish aren’t present avoids construction-related impacts Avoidance Measures for Intermediate-to Long-term habitat effects • What duration are the effects? • What frequency of fish presence? • Get your “offsetting+” measures in place and make sure they are effective before fish are reasonably expected to experience the impacts -(it must be equivalent or better habitat) Whydo we have to do this? • Juvenile salmonids need floodplain habitat for refuge, to feed, and to grow. • Bigger juvenile salmonids are less vulnerable to predation. • Bigger juvenile salmonids survive better when they reach the estuary and move into the ocean. Fish without flood plain rearing Fish with flood plain rearing