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

• we 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

• oms, e tc .

Tonight’s Agenda

• 1. Intr
• duc tions
• 2. Me e ting Goals
• 3. Pr
• gr

am Ove r vie w

• 4. Data Ove r

vie w

• 5. Online Re sour

c e s

• 6. T
• 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!)

• f the r

e ma pping pr

• c e ss
• 2. Pr
• vide 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

• n 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?

www.c olor adohazar dmapping.c om

www.c olor adohazar dmapping.c om

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

L e ft Hand Cr e e k (@ Ho ve r Rd)

• Upda te d– 5,810 c fs (26% inc re a se )
• E

ffe c tive F E MA – 4,610 c fs

L e ft Hand Cr e e k (@ Hwy 119)

• Upda te d – 6,037 c fs (31% inc re a se )
• E

ffe c tive F E MA – 4,610 c fs

L e ft Hand Cr e e k (@ N 73rd St)

• Upda te d – 6,037 c fs (5% de c re a se )
• E

ffe c tive F E MA – 6,330 c fs

L e ft Hand Cr e e k(@ N 63rd St)

• Upda te d – 5,994 c fs (5% de c re a se )
• E

ffe c tive F E MA – 6,330 c fs

L e ft Hand Cr e e k (@ Hwy 36)

• Upda te d – 5,794 c fs (14% de c re a se )
• 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

L e ft Hand Cr e e k (@ Hwy 119)

8,700 c fs (100-500 yr e ve nt)

L e ft Hand Cr e e k (@ N 63rd St)

7,000 c fs (100-500 yr e ve nt)

L e ft Hand Cr e e k (@ Old Sta g e Rd)

3,520 c fs (50-100 yr e ve nt)

Why & how are the maps changing?

• Cur

r e nt maps fr

• m 1981
• Impr
• ve d te c hnologie s

in mode l de ve lopme nt

• Mor

e data available

1981 study: 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

• c al Role (Boulde r

County)

• Adoption of floodplain mapping and c ode
• F

lood r isk mapping par tic ipation

Ultimate Go al – Pr

• te c t L

ife , He alth, & Safe ty

Timeline revisited

Now Boulde r County is r e vie wing the CHAMP hydr aulic s and floodplain mapping Summe r 2018

• F

E MA will r e vie w the CHAMP hydr aulic s and floodplain mapping

• 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

Early 2018 Mid 2018 Late 2018 Early 2019 2019 2021+

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 F loodplain

Solid c olor ar e as =

c urre nt re g ula to ry flo o dpla ins

L e tte r s = Ma p Zo ne s

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

• m your

r e vie w:

• Struc ture loc a tions – a c c ura te ?
• Pla nne d work?
• T
• pog 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

DE ADL INE for c omme nts for this ar e a: MAY 6th

Re ma pping Point of Conta c t: E rin Coope r floodpla inma psc omme nt@boulde rc ounty.org