introduction project overview - arroyo seco workshop... · 4 24,000 afy 14,000 afy existing supply...

April 29, 2013

Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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24,000 AFY

14,000 AFY

Existing Supply Mix

(Groundwater & canyon water)

22,800 AFY

14,000 AFY

1,200 AFY

Future Supply Mix with Arroyo Seco Canyon Project

(Groundwater & canyon water)

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Reduce dependence on imported water

Drought-tolerant water supply through groundwater recharge

Cost Savings◦ Imported Water: $1,000/AF◦ Groundwater: $130/AF

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Groundwater

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Sediment and debris deposits:◦ Damaged Headworks area◦ Reduced flow diversion◦ Compromised recharge capacity

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Feb 2010

Average

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Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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Headworks

JPL Parking Lot

Arroyo Intake Structure

Existing Spreading Basins

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Area 1 – Headworks

Area 2 – Diversion Dam & Intake

Area 3 – Spreading Grounds & JPL parking lot

Remove Headworks dam

Naturalize area and restore riparian habitat

Install new restroom

Install recreational & educational facilities

Remove portion of fence

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Construct a new diversion dam

Replace intake trash rack

Install a fine screen to improve aquatic protection

Install educational signage

Remove K-rail & improve road

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Remove JPL Parking Lot (~1000 spaces)

Construct smaller parking lot (~100-150 spaces)

Construct a new access road for JPL employees

Expand spreading basins (from ~13 to 21 acres)

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Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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Headworks Dam5-yr Flood Plain

Water Fountain

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10-yr Flood Plain

50-yr Flood Plain

Ranger Station

Trail

Demolish Headworks Dam Naturalize stream Restroom and drinking

fountain Horse trough Picnic tables Garbage cans Signage Trail

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Picnic Tables

Headworks

Garbage Cans

Islands

Willow Posts

Horse trough

Restroom

Signage

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Nature Trail

Picnic Area

Main Channel (low flow)

High Flow Channel

Planting Islands

Restroom

Naturalization Area

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After 3 yearsAfter 3 months

Las Virgenes Creek, Calabasas

Dec 2007

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Building type◦ Prefabricated◦ Custom build on-site

Size◦ 1 Male/Female stall◦ 2 Male/Female stalls

Disposal method◦ Septic Tank System◦ Composting Toilet

Restroom

Ranger Station

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At restroom:Style: 1 large signTopic: Water quality benefits

In naturalized area:Style: multiple small plates and/or rocksTopics: stream restoration, native vegetation,

dynamic riparian ecosystem

Headworks demolition Stream Restoration Restroom and fountain Horse trough Picnic tables Garbage cans Signage Trail

Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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Bridge No. 3

IntakeDiversion Dam

Former Chlorination

Station

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Diversion Dam Intake Temporary

bridge Road repair Signage

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Signage

New Intake

Temporary Bridge

Road repair

New Diversion Dam

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Bascule gate

Flash Board diversion weir

Obermeyer spillway gate

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Pros Cons

Obermeyerspillway gate

High reliability High capital cost

Ease of operation Sole source availabilityLow Headwater during flood eventsCaptures most water

Bascule gate High reliability High capital cost

Ease of operation

Extreme durability

Low Headwater during flood events

Captures most water

Flash Boards weir

Low capital cost Dangerous to operate during stormLow reliabilityPoor aestheticsPoor control of HeadwaterNo automation

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Abutment Plate

Intake

Sediment deposits

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New Trash Rack

New Fine Screen

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At new dam & intake:Style: small plateTopics: diversion dam operations

aquatic habitat protection

Signage

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New diversion dam New intake Road improvement/

K-rail removal Temporary bridge Signage

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Introduction

Project Overview

Conceptual Design – Area 1

Conceptual Design – Area 2

Conceptual Design – Area 3

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Pipeline from Intake

County Storm Drain

Utilities

Behner WTP

Spreading Basins

JPL Parking Lot

yEquestrian

Pathway

JPL

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New basins with pre-sedimentation

Small recreational parking lot

Access Road Utility relocation New pipes JPL Well Signage

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Signage + Pet Waste StationRoundabout

Equestrian Pathway(existing)

Stairway

Walkway

New Linear Parking

New Access Road

Roundabout

New Spreading Basins

JPL Well

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Linear Parking Lot 10 New Basins:◦ 2 Pre-sedimentation◦ 8 Spreading/Recharge

Pre-sedimentationBasins

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Roundabout

Equestrian Pathway(existing)

Stairway

WalkwayNew

Parking

New Access Road

New Parking

New Spreading Basins

JPL Well

Signage + Pet Waste Station

Parking Lot North End 9 New Basins:◦ 2 Pre-sedimentation◦ 7 Spreading/Recharge

Pre-sedimentationBasins

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66 ft

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ADA Parking

Interpretative Signage

Stairway (Trail Access)

Walkway

New Parking

North Side

Parking for Hahamongna

Watershed Park Visitors

Access via Explorer

Road

New Basins New Access

Rd

South Side

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At the trail head:Style: small plateTopics: spreading basins and groundwater recharge operations, local supply benefits

Signage

Annual saving ~ 1,200 afy x $870/af ~ $1 M/yr Payback Period ~ 5 years

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AreaAnnual

Recharge (af/yr)Existing 2,000

New 1,200Total 3,200

Area Estimate CostArea 1 $900,000Area 2 $1,100,000Area 3 $2,700,000Total $4,700,000

ESTIMATED PROJECT COST ESTIMATED PROJECT YIELD

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New basins with pre-sedimentation

New recreational parking lot Access road Walkway/Stairway Equestrian Trail Pet waste station Signage

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Roundabout

Equestrian Pathway(existing)

Stairway

WalkwayNew

Parking

New Access Road

New Parking

New Spreading Basins

JPL Well

Signage + Pet Waste Station

Pre-sedimentationBasins

E-mail Natalie Ouwersloot by Monday May 6nouwersloot@cityofpasadena.net

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