Month, Day, Year

Alameda County Water District

Stormwater as a Resource:

Opportunities and Challenges

ACWA 2016 Fall Conference & Exhibition

December 1, 2016

Overview of ACWD

2

Founded in 1914

ACWD serves Fremont, Newark, and Union

City

~105 sq. mi. Service area

~344,000 Population

~83,000 Customer connections

ACWD Water Supply Sources – Typical

40%

40%

20%

Alameda Creek WatershedRunoff (includes brackishGW desal)

State Water Project

San Francisco PUC

3

ACWD’s Local Water Supply

4

• Alameda Creek drains a 633 sq. mi. watershed

• Urban & Rural Areas

Alameda Creek

Flood Control Channel

Legend

Diversion

Rubber

Dam

Drop Structure

(“BART Weir”)

Middle Rubber Dam

5

Lowest Inflatable Rubber Dam: Removed from

service in 2009

Upper Rubber Dam

Sea Level

SAN FRANCISCO BAY

100

-100

-200

-300

-400

-500

-600

-700

-800

FREMONT AQUIFER

CENTERVILLE AQUIFER

NEWARK AQUIFER

DEEP AQUIFERS

HA

YW

AR

D

FA

UL

T

DE

PT

H I

N F

EE

T

QUARRY LAKES

Niles Cone Groundwater Basin:

Seawater Intrusion

6

BEDROCK

Sea Level

SAN FRANCISCO BAY 100

-100

-200

-300

-400

-500

-600

-700

-800

FREMONT AQUIFER

CENTERVILLE AQUIFER

NEWARK AQUIFER

DEEP AQUIFERS

HA

YW

AR

D

FA

UL

T

DE

PT

H I

N F

EE

T

ABANDONED WELLS

Niles Cone Groundwater Basin:

Seawater Intrusion

7

Sea Level

SAN FRANCISCO BAY 100

-100

-200

-300

-400

-500

-600

-700

-800

FREMONT AQUIFER

NEWARK AQUIFER

DEEP AQUIFERS

HA

YW

AR

D

FA

UL

T

DE

PT

H I

N F

EE

T

ARP WELLS

Niles Cone Groundwater Basin:

Aquifer Reclamation Program

8

ABANDONED WELLS

Newark Desalination Facility

9

Niles Cone Groundwater Basin

Alameda Creek

PT Wellfield Mowry Wellfield

“Active” annual stormwater diverted under water

rights: 19,000 AF/year (typ.) – urban and rural

watershed

“Passive” deep percolation: 9,000 AF/year (average) –

urban

Direct stormwater runoff to Quarry Lakes: between

200 to 2,000 AF/year – urban

Groundwater basin capacity is limited in wet years

Existing Stormwater Capture

Protecting and Restoring

Groundwater Quality

Niles Cone Groundwater Mgm’t and Protection

Treated similar to a pristine watershed

ACWD Operational Protocols for Diversions from

Alameda Creek

Water Quality

Fish Passage (future)

Actively monitor watershed activities

Secured ban of hazardous material truck transport in

Niles Canyon

Cooperative Agreement with RWQCB

ACWD lead agency for management of LUFT and SCP sites

SB 133 – ACWD Groundwater Protection Act

Stormwater Recharge

Direct stormwater runoff to Quarry Lakes

Protecting and Restoring

Groundwater Quality

Work with Land Use planning agencies to

established standards and prohibitions on direct

infiltration

Balance NPDES’ Low Impact Development (LID)

approaches with protecting groundwater quality

Sensitive recharge areas, “high risk” situations-such as high

traffic & industrial areas, automotive repair shops, active

cleanup sites

Strategies to reduce the amount of runoff, e.g, on-site reuse,

Treatment Measures, eg., bioswales vs. infiltration devices

Public education program to curb illegal

dumping, especially into storm drains

Redirect Drainage into Quarry Lakes

Theoretical Quantity = 2,000 to 6,000 AF/year

Groundwater basin capacity limitations limits yield

Detention and pollution mitigation issues (hydrocarbons and other

vehicle related chemicals, pesticides)

High cost

Decentralized run-off detention systems, cisterns and rain-

barrels

Slow release after storm events in shoulder seasons

Modest yield = 200 acre-feet

Rain barrel rebate program

Great for public education!

Future Stormwater Capture

Opportunities

Regional and local urban and rural stormwater capture is

already part of ACWD’s water supply portfolio

Limited groundwater storage capacity and business case

challenges limit expansion potential

Protecting groundwater quality remains an important

objective for ACWD

ACWD is working with local cities and individual

customers to maximize on-site capture, as appropriate

Final Thoughts