Public Review of Draft Boulder County Floodplain Maps Apr il 12, - PowerPoint PPT Presentation

Public Review of Draft Boulder County Floodplain Maps Apr il 12, 2018 Boulde r County Par ks & Ope n Spac e Middle & L owe r L e ft Hand Cr e e k

HOUSEKEEPING Sign- in she e t • Ne wsle tte r s & • F lye r s Snac ks, • r e str ooms, e tc .

Tonight’s Agenda 1. Intr oduc tions 2. Me e ting Goals 3. Pr ogr am Ove r vie w 4. Data Ove r vie w 5. Online Re sour c e s 6. T o the T able s!

Introductions E rin Coope r, Boulde r County • Va rda Blum, Boulde r County • Ge off Uhle ma nn, AE COM (CWCB) • Ke vin Doyle , Mic ha e l Ba ke r Intl. • E rin Ma y, F E MA • Additiona l Boulde r County Support Sta ff •

Meeting goals: 1. Infor m r e side nts & la ndowne r s (you!) of the r e ma pping pr oc e ss 2. Pr ovide oppor tunity for public c omme nt be for e the F E MA a ppe a l pe r iod 3. Ha ve a fa ir & ope n disc ussion

Colorado Hazard Mapping Program (CHAMP) Why is this study be ing c onduc te d? Ha za rds c ha ng e • F loodpla in de line a tions a re ofte n outda te d • Ma ps re g ula rly upda te d a c ross the c ountry by F E MA, Sta te s, Communitie s • T he Sta te of CO initia te d CHAMP a fte r the F lood of 2013 • Cha ng e s to flooding c ha ra c te ristic s • Cha ng e s to unde rsta nding of ra infa ll • Why doe s it impac t you? Know if you a re a t risk for flood ha za rds • Will re vise F lood Insura nc e Ra te Ma ps tha t impa c t insura nc e ra te s (ba se d • on risk) Re g ula tion is re la te d to flood zone / floodwa y • Whe r e will the r e be c hange s?

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Colorado Hazard Mapping Program What happe ns ne xt? T he re a re still multiple re vie ws tha t will oc c ur, so da ta is subje c t to c ha ng e • Boulde r County be ing proa c tive to bring this informa tion to you in dra ft • form T his is a first look for you to g e t your input we ll in a dva nc e of da ta • fina liza tion Whe n will c hange s go into e ffe c t? CHAMP te a m will re vie w c omme nts • F E MA will re vie w da ta in spring / summe r 2018 • Da ta will be put onto pre limina ry F lood insura nc e Ra te Ma ps la te • 2018/ e a rly 2019 A forma l 90 da y a ppe a l pe riod will c omme nc e whe re a nyone c a n • a ppe a l ma ps with te c hnic a l da ta Onc e re solve d, ma ps will be re le a se d a s fina l (e ffe c tive ), like ly 2021 •

Modeled Flows Upda te d vs. E ffe c tive Disc ha rg e s of the 100- yr F lood E ve nt • Upda te d– 5,810 c fs (26% inc re a se ) L e ft Hand Cr e e k (@ Ho ve r Rd) • E ffe c tive F E MA – 4,610 c fs • Upda te d – 6,037 c fs (31% inc re a se ) L e ft Hand Cr e e k (@ Hwy 119) • E ffe c tive F E MA – 4,610 c fs • Upda te d – 6,037 c fs (5% de c re a se ) L e ft Hand Cr e e k (@ N 73 rd St) • E ffe c tive F E MA – 6,330 c fs • Upda te d – 5,994 c fs (5% de c re a se ) L e ft Hand Cr e e k (@ N 63 rd St) • E ffe c tive F E MA – 6,330 c fs • Upda te d – 5,794 c fs (14% de c re a se ) L e ft Hand Cr e e k (@ Hwy 36) • E ffe c tive F E MA – 6,700 c fs

Experienced Flows E stimate d Pe ak Disc har ge s E xpe r ie nc e d in 2013 F lood 8,700 c fs (100-500 yr e ve nt) L e ft Hand Cr e e k (@ Hwy 119) 7,000 c fs (100-500 yr e ve nt) L e ft Hand Cr e e k (@ N 63 rd St) 3,520 c fs (50-100 yr e ve nt) L e ft Hand Cr e e k (@ Old Sta g e Rd)

Why & how are the maps changing? Cur r e nt maps fr om 1981 • 1981 study: Impr ove d te c hnologie s • in mode l de ve lopme nt Mor e data available • CHAMP: What’s not in the maps? • De b ris • Ditc he s

Left Hand Creek Projects CDOT Hwy 36 bridge

Roles and Responsibilities F e de r al Role (F E MA) F lood Risk Mapping • F lood Risk Manage me nt • F lood Insur anc e – available to anyone in Boulde r County • State Role (CWCB) Community assistanc e • F lood Risk Mapping • L oc al Role (Boulde r County) Adoption of floodplain mapping and c ode • F lood r isk mapping par tic ipation • Ultimate Go al – Pr o te c t L ife , He alth, & Safe ty

Timeline revisited Early 2018 Mid 2018 Late 2018 Early 2019 2019 2021+ Boulde r County is r e vie wing the CHAMP hydr aulic s and Now floodplain mapping F E MA will r e vie w the CHAMP hydr aulic s and floodplain • mapping Summe r 2018 Boulde r County to adopt CHAMP floodplain as “be st • available data” E ar ly 2019 CHAMP Pr e liminar y F lood Insur anc e Rate Maps issue d 2019 F E MA Appe als Pe r iod for CHAMP mapping 2021 F E MA F lood Insur anc e Rate Maps be c ome e ffe c tive all date s sub je c t to c hang e

Hatc he d laye r s ar e same laye r type s as online ; pr inte d in c olor for e ase of vie wing Blue = F loodway Gr e e n = F lood F r inge Or ange = 500- ye ar loodplain F

Solid c olor ar e as = c urre nt re g ula to ry flo o dpla ins s = Ma p Zo ne s L e tte r

County Floodplain Remapping http:/ / BoCoF loodpla inRe ma pping .c om

Using the Map Review Website

Draft Maps at the Tables What we ’d like to le ar n fr om your r e vie w: • Struc ture loc a tions – a c c ura te ? • Pla nne d work? • T opog ra phic de ta ils • Impa c ts to wa te r flow Comme nts! • Ple a se inc lude name & c o ntac t info on ma ps • Use c omme nt forms • If you think the ma p ne e ds re vision, te ll us WHY e a: MAY 6 th DE ADL INE for c omme nts for this ar Re ma pping Point of Conta c t: E rin Coope r floodpla inma psc omme nt@boulde rc ounty.org