Coastside County Water District

766 Main Street

Half Moon Bay, California  94019-1995

Phone: (650) 726-4405                               Fax: (650) 726-5245

Web: coastsidewater.org

 

Service Area

 

Coastside County Water District provides water to the City of Half Moon Bay and several unincorporated coastal communities in San Mateo County, including El Granada, Miramar, and Princeton by the Sea (Pillar Point Harbor).

 

System

 

Profile

 

Area Size

14 square miles

Service Population

18,789

Number of Accounts

7,604

Number of SF RWS Connections

2

Connections To SF RWS Mains

Upper Crystal Springs Intake and Pilarcitos Reservoir at Stone Dam

Avg. Day Demand (mgd)

1.82

Avg. Day Purchases From SF RWS (mgd)

1.45

%  Demand Met With SF RWS Supplies

79.63%

Maximum Local Water Production (mgd)

0.5

Alternative Supply Sources

During a drought, local production is extremely low due to dependency on surface stream flows and a small watershed.

Interties With Other Agencies

None

Local Storage (mg)

8.0

Days of Storage

Approximately 3 days

 

Summary

 

Coastside County Water District has four water sources; (1) Pilarcitos Lake at Stone Dam, (2) Crystal Springs Reservoir, (3) the Pilarcitos Creek Infiltration Well Field, and (4) the Denniston (groundwater and surface water) Project. Water purchased from the SF RWS is supplied from two different raw water sources: Pilarcitos Lake at Stone Dam and Upper Crystal Springs Reservoir.


Raw water from Upper Crystal Springs Reservoir, Pilarcitos Lake at Stone Dam and the Pilarcitos Creek Infiltration Wells terminate at the Nunes Water Treatment Plant. Raw water from Denniston Creek and the Denniston Well Field terminate at the Denniston Water Treatment Plant.

 

 

Water Supply and Demand

 

Supply by Source

Actual
FY 17-18
(ccf)

Actual
FY 18-19
(ccf)

Actual
FY 19-20
(ccf)

Actual
FY 20-21
(ccf)

San Francisco Water

464,037

547,861

496,627

705,680

Local Groundwater

29,278

10,508

12,272

12,099

Surface Water

408,890

314,412

382,259

168,436

Recycled Water

0

0

0

0

Total

902,206

872,781

891,158

886,215

mgd equivalent

1.85

1.79

1.83

1.82

 

 

 

 

 

Demand by Sector

 

 

 

 

Residential

464,899

446,167

486,477

499,242

Commercial/Industrial

46,566

48,065

46,340

41,741

Other

165,626

266,457

255,259

163,455

Dedicated Irrigation

136,865

41,335

48,645

144,202

Non-Revenue Water

88,250

70,757

54,437

37,575

Total

902,206

872,781

891,158

886,215

mgd equivalent

1.85

1.79

1.83

1.82

 

 

 

 

 

Per Capita Use

Actual
FY 17-18
(gpcpd)

Actual
FY 18-19
(gpcpd)

Actual
FY 19-20
(gpcpd)

Actual
FY 20-21
(gpcpd)

Residential

57

54

53

54

Gross

110

78

97

97

 

Facilities and Distribution

Treated Water Storage Reservoirs

 

Designation

Type

Capacity (mg)

Denniston

Steel

1.50

El Granada 1

Steel

0.20

El Granada 2

Steel

0.15

El Granada 3

Steel

0.25

Miramar

Steel

1.00

Carter Hill

Steel

0.40

Carter Hill

Steel

0.60

Carter Hill

Steel

1.50

Miramontes

Steel

0.40

Alves

Steel

2.00

 

 

 

Total

 

8.00

 

Surface Water Treatment Facilities

 

Designation

Capacity (mgd)

Nunes WTP

4.5

Denniston WTP

1.0

Total

5.5

 

Wells

 

Name

Capacity (gpm)*

Status

D1

25

Active

D2

 

Inactive

D3

37

Inactive

D4

35

Inactive

D5

35

Inactive

D9

45

Active

P1*

40

November 1-March 31

P2*

 

Inactive

P3**

 

Active

P3A*

 

Active

P4*

100

November 1-March 31
Standby

P4A*

200

November 1-March 31

P5*

65

November 1-March 31

Total

 

635


*Surface water infiltration wells