JULY 201930% DESIGN PHASE

IMPROVING OUR COMMUNITIESwith Natural Drainage Systems (NDS)

What are they & why do we need them?When it rains in the Delridge and Westwood neighborhoods, pollution from our streets runs into Longfellow Creek untreated. This is not healthy for the creek or for people. The good news is: there is something we can do.

Natural Drainage Systems consist of shallow depressions in the public right-of-way, or “planter strip,” filled with deep-rooted plants and spongy soils that temporarily hold and clean polluted stormwater from streets and sidewalks. These features capture and clean pollutants before they can reach the creek.

Seattle Public Utilities (SPU) is planning to build natural drainage systems in your neighborhood in 2020-2021.

Community benefitsNatural Drainage Systems offer multiple benefits to local neighborhoods and ecosystems, including:

Greener, more attractive neighborhoods

Lower risk of flooding

Creation of habitat along our streets

Healthier creek ecosystems

Calmer traffic patterns

More street trees

What is the NDS Partnering Program?The 2016-2025 Natural Drainage Systems Partnering Program is a Seattle Public Utilities multi-year capital improvement program focused on Longfellow, Piper’s, and Thornton Creek watersheds.

The program’s goal is to construct street-side natural drainage systems that filter and manage stormwater and improve neighborhoods with street trees, traffic calming, and, in some cases, a limited number of sidewalks.

We are partnering with Seattle Department of Transportation (SDOT), Office of Arts & Culture 1% for the arts, and King County Flood Control District.

LONGFELLOW CREEK NDS PROJECT

JULY 201930% DESIGN PHASE

ELLIOTT BAY

DUWAM

ISH RIVER

PUGET SOUND/SALISH SEA

ROXHILLPARK

LONGFELLOW CREEK WATERSHED BOUNDARY

NOTES:-ALL BLUE SHADED AREAS FLOW INTO LONGFELLOW CREEK.-THE DASHED LINE OF LONGFELLOW CREEK INDICATES WHERE THE CREEK IS IN A PIPE.

SW BARTON ST

SW HENDERSON ST

SW TRENTON ST

SW CLOVERDALE ST

SW THISTLE ST

SW ROXBURY ST

24TH

AVE

SW

SW HOLDEN ST

SW KENYON ST

SW BRANDON ST

WEST SEATTLE BRIDGE

SW GENESEE ST

SW MORGAN ST

PROJECT AREA

LONGFELLOW CREEKLONGFELLOW CREEK WATERSHED BOUNDARY

LONGFELLOW CREEKWatershed Boundary

NOTES• All blue-shaded areas flow

into Longfellow Creek• The dashed line of

Longfellow Creek indicates where the creek is in a pipe

N

JULY 201930% DESIGN PHASE

2019 2020

OUTREACH FOR 30% DESIGNMID 2019

OUTREACH FOR 60% DESIGNLATE 2019 / EARLY 2020

30%DESIGN

REFINE PROJEC

T SCOPE

AND DEVELOP DES

IGN

CONSTRUCTIO

N

PRE-CONSTRUCTIONOUTREACHMID 2020

DRAFT POTE

NTIAL D

ESIG

N

FINALIZ

E + OBTA

IN PERMITS

60%DESIGN

SITING, FIELD INVESTIGATIONSSURVEY + CONCEPT DEVELOPMENT2017 to 2018

FINALDESIGN

60% INPUTS• Neighborhood priori�es• Local ecosystem needs• Detailed u�lity loca�ons + impacts• Plan�ng pale�es & new street trees• NDS sizing adjustments• Refinements to design dimensions + details• City right-of-way impacts• Balance of costs with budget• Maintenance of NDS• Permi�ng• Community concerns

FINAL INPUTS• Accessibility impacts• Contruc�on costs + impacts• Ongoing maintenance costs + responsibility• Permi�ng requirements• Construc�on ques�ons

We Are Here

A Healthier & Safer Longfellow Creek!

The Longfellow Creek Natural Drainage System (NDS) Project has completed preliminary planning and field inves�ga�ons.

At the 30% Design Phase we present poten�al street and drainage improvements to the community, answer ques�ons, and gather community concerns as we work toward finalizing the project scope based on regulatory requirements and project funding.

30% INPUTS• Neighborhood priori�es• Current drainage condi�ons• Loca�on of u�li�es• Local topography + mature trees• Rainfall runoff pa�erns along the street• Soil tes�ng + analysis• Loca�on of homes + paths• Loca�on of driveways• On-street parking pa�erns• City right-of-way impacts• Zoning code• Projected construc�on costs• Maintenance of NDS• Permi�ng• Community concerns

2021

WHERE WE ARE NOW...and where we’re going

JULY 201930% DESIGN PHASE

WHAT WE HEARDyou’d like to incorporate in NDS and path design

55513725242418141010106

Fix the path so it’s not so muddy

Add more lighting

Clean up litter and garbage

Improve visibility along the path

Replace the bridge

Plant new trees along the path

Make the path and bridge better for bikes, strollers, wheelchairs

Add places to sit

Slow traffic down along 24th Ave SW and SW Kenyon St

Other change (descriptions at right)

Add educational signs that explain importance of watershed

Remove the parking at the street end

0No change is necessary

• More police patrol• Add a trash can• Add street lights on SW Kenyon St• Add covered seating to bench• Double the amount of plants• Concerned about fast turnout at

24th and Kenyon cul-de-sac

24TH

AVE

SW

for SW Kenyon St at 24th Ave SW

JULY 201930% DESIGN PHASE

LONGFELLOW CREEK PATHLO

NG

FELL

OW

VIE

W LO

OKI

NG

EAS

TLO

NG

FELL

OW

VIE

W LO

OKI

NG

WES

T

JULY 201930% DESIGN PHASE

new accessible curb ramps

natural drainage system (nds)

improved path with pedestrian lighting

new sidewalk raised walkway with pedestrian lighting

key

section a-a (1”=4’)

city right-of-waycity right-of-way

right-of-way dedication

city

rig

ht-

of-

way

lon

gfe

llo

w

cree

k

long

fell

ow

cree

k

24th

ave

sw

sw kenyon st

exist. water main

potential path lighting(dependent on budget)

improvedpath natural drainage

system

underdrain

bicycle ramp

existing longfellow creek legacy trail marker

a

a’

b

c

bridge to be replaced

natural drainage system

city

rig

ht-

of-

way

city

rig

ht-

of-

way

potential nds and pathway improvementssw kenyon street and 24th ave sw

planting strip/lawn restoration

LONGFELLOW CREEK PATHPotential NDS and Pathway Improvements SW Kenyon St and 24th Ave SW

new accessible curb ramps

natural drainage system (nds)

improved pathnew sidewalk raised walkway

key

section a-a (1”=4’)

city right-of-waycity right-of-way

right-of-way dedication

city

rig

ht-

of-

way

lon

gfe

llo

w

cree

k

long

fell

ow

cree

k

24th

ave

sw

sw kenyon st

exist. water main

potential path lighting(dependent on budget)

improvedpath natural drainage

system

underdrain

bicycle ramp

existing longfellow creek legacy trail marker

a

a’

b

c

bridge to be replaced

natural drainage system

city

rig

ht-

of-

way

city

rig

ht-

of-

way

potential nds and pathway improvementssw kenyon street and 24th ave sw

planting strip/lawn restoration

new accessible curb ramps

natural drainage system (nds)

improved pathnew sidewalk raised walkway

key

section a-a (1”=4’)

city right-of-waycity right-of-way

right-of-way dedication

city

rig

ht-

of-

way

lon

gfe

llo

w

cree

k

long

fell

ow

cree

k

24th

ave

sw

sw kenyon st

exist. water main

potential path lighting(dependent on budget)

improvedpath natural drainage

system

underdrain

bicycle ramp

existing longfellow creek legacy trail marker

a

a’

b

c

bridge to be replaced

natural drainage system

city

rig

ht-

of-

way

city

rig

ht-

of-

way

potential nds and pathway improvementssw kenyon street and 24th ave sw

planting strip/lawn restoration

KEY

SECTION A-A’