Ventura County
Watershed Protection District

Flood Hazard Impact Report

Lower Conejo Creek (Monitor Id 375/376)

Lower Conejo Creek Highway 101 to Calleguas Creek

 GIS Hot Spot ID: 

375-2   Highway 101 at Conejo Creek

375-3   Agricultural Fields below Highway 101

375-4   Agricultural Fields below Ridge View Bridge

375-5   Camarillo Springs Golf Course and Ridge View Road

375-6   Lower Camarillo Springs Residences

375-7   Adohr Road and Camarillo Industrial area south of Adohr Road

376-1    Camarillo Sanitation Plant

376-2    Agricultural Fields adjacent to Conejo Creek below Sanitation Plant

376-3    Agricultural Fields and Howard Road

The major areas of concern are the residences in Camarillo Springs near Conejo Creek and the Camarillo Sanitation Plant.  Flooding away from the areas next to the creeks is widespread but shallow.  This can impact the roads leaving people stranded.

  

Historical Data

 Major flooding occurred along this stream of Conejo Creek in 1980 and 1983.  Images of the damages are shown below.  In 2005 minor flooding of the agricultural fields below Highway 101 at the Ridge View Bridge occurred.  The table below shows the observed peaks at the Conejo Creek above Highway 101 (800) stream gage and the damages that occurred.

Date

Flow at 800

Areas Affected

2/16/1980

11,840 cfs

Flooding of agricultural fields and Camarillo Springs Golf Course.

3/1/1983

13,300 cfs

Extensive flooding of the Camarillo Sanitation Plant, agricultural fields and the Camarillo Springs Golf Course and residential area.  It is unknown if Highway 101 was flooding.

1/9/2005

5,990 cfs

Flooding of the agricultural fields between Highway 101 and Ridge View Raod.

  

Aerial Photo and Map

 

Photos of Area


Camarillo Springs Golf Course and residential area, VCWPD photo 1983


Camarillo Sanitation Plant, VCWPD photo 1983


Flooding of agricultural fields below Highway 101 and above Ridge View Bridge, NWS 2005

Gages

There is one stream gage located upstream at Conejo Creek above Highway 101.  This stream gage is a float gage located just downstream of the confluence of Conejo Creek and the Arroyo Santa Rosa.  There are no large tributaries between the gage and the problem area.

 

Special Conditions/ Issues

Many residence of Camarillo Springs area are senior citizens and may need additional assistance evacuating.

 

Minimal Time for Implementation

2-4 hours to evacuate the Camarillo Springs and industrial areas.

  

Normal Conditions Procedure

Gages Used:  800

Criteria

Value

Issue

Area

Procedure

Flow

4,0000 cfs

Agricultural Fields below Highway 101

275-3

Watch flow for the potential of minor flooding of the agricultural fields between Highway 101 and Ridge View Road.

Flow

4,500 cfs

Agricultural Fields below Highway 101

275-3

Warning flow for minor flooding of the agricultural fields between Highway 101 and Ridge View Road.  Conejo Creek nearing channel capacity.

Flow

5,500 cfs

Agricultural Fields below 101, Camarillo Springs Golf Course

275-3, prep 375-5

Minor flooding of the agricultural fields should be occurring.  Watch for flow to approach the Camarillo Springs Golf Course.

Flow

6,000 cfs

Agricultural fields below Ridge View and below sanitation plant

375-4, 376-2

Watch flow for possible flooding of agricultural fields below Ridge View Road and the Camarillo Sanitation Plant and for the agricultural fields below the sanitation plant.

Flow

6,500 cfs

Camarillo Springs Golf Course

375-5

Warning flow for flooding of the Camarillo Springs Golf Course.

Flow

7,000 cfs

Camarillo Springs residences

375-5

Watch flow for possible flooding of the lower Camarillo Springs residences located closest to Conejo Creek next to the golf course.  Consider evacuation of elderly residences.

Flow

7,000 cfs

Camarillo Sanitation Plant

376-1

Watch for possible flooding of Camarillo Sanitation Plant.  If forecasted flows are expected to be several thousand cfs higher, plant personnel may need to start preparations for potential flooding.  Coordinate through OES

Flow

7,000 cfs

Agricultural fields below Ridge View and below sanitation plant

375-4

Warning of flooding of the agricultural fields.  Some minor flooding may be occurring along section of Conejo Creek.  Major roads should not be impacted at this flow.

Flow

7,000 cfs

Agricultural fields west of Conejo Creek, Adohr Road

375-4, prep 375-7, 376-3

Flooding of agricultural fields extending west of Conejo Creek.  Watch issued for impacts to Adohr Road and Camarillo Industrial area if flows are forecasted to be significantly higher.

Flow

7,500 cfs

Camarillo Springs Golf Course

375-5

Lower section of the golf course should be flooded.  Ridge Road may be impacted.

Flow

8,000 cfs

Camarillo Springs residences

375-5, prep 375-6

Flooding has already impacted the golf course and should be approaching the lower residences.  The lower residences (Margarita Ave) should be evacuated Ridge Road may be impacted so evacuations should be through Camarillo Springs exit of Highway 101

Flow

8,000 cfs

Lower Agricultural Fields below sanitation plant

376-2, 376-3

Flooding should be occurring on agricultural fields south of Howard Road.  Potential for flows to cross Howard Road if flows are forecasted to be higher.

Flow

9,000 cfs

Camarillo Springs residences

375-5, 375-6

Lower residences along Margarita Ave should be flooded.  Consider potential evacuations for residences further up Margarita Ave and Isabel Ave.

Flow

9,000 cfs

Highway 101

375-2

Potential exists for flooding of Highway 101 bridge if flows are forecasted to be over 10,000 cfs.  Notify CHP through OES of potential closure and the need for monitoring.

Flow

9,000 cfs

Adohr Road and industrial area

375-7

Flows may be impacting Adohr Road and the industrial area to the west should be evacuated if flows are expected to be higher.

Flow

9,500 cfs

Camarillo Sanitation Plant

376-1

Sanitation Plant should be prepared for flooding.  Worker may need rescuing due to roads in the area being flooded including Howard and Pancho.

Flow

10,000 cfs

Agricultural fields and industrial area

376-3

All roads east and south of the industrial area should be flooded.  The eastern and southern areas of the industrial area should be evacuated.

Flow

10,000 cfs

Highway 101

375-2

Flooding of Highway 101 Bridge may be occurring on westbound lanes.  CHP patrols should be occurring

Flow

10,000 cfs

Camarillo Springs residences

375-6

Evacuations of residences Isabel Ave should be underway.  Lower residences along Margarita Ave are under significant water.

Flow

11,000 cfs

Highway 101

375-2

Significant flooding should be occurring in the westbound lanes.  Flooding may be occurring on the eastbound lanes.  Potential hard closure of Highway 101 at Conejo Creek.

Flow

11,000 cfs

Camarillo Sanitation Plant

376-1

Sanitation plant should have flooding.  And may have extensive damage.

Flow

11,000 cfs

Industrial area

375-7, 376-3

Flooding may be occurring along the eastern and southern parts of the industrial area.

Flow

13,000 cfs

Area between Conejo Creek and Calleguas Creek south of Pleasant Valley Road

375-7, 376-3

Extensive flooding of area between Conejo and Calleguas Creeks.  Flooding occurring across industrial area.  All roads in this are may be impassible.

  

Data Source

 Original polygons were drafted from the January 2005 meeting with former County Hydrologist and experts.  The polygons were refined from known extent of flooding during the 1983 flood event.  Extent of flooding to the west of Conejo Creek is unknown.