Draft Flood Management Facilities Inventory
Otay River Watershed Management Plan
Flood Management Facilities Inventory
Background
The Otay River watershed lies in the southeastern portion of San Diego County, California.
Development in the watershed is largely concentrated downstream of the Lower Otay Reservoir
within the Cities of San Diego and Chula Vista. Upstream of the reservoir, development in the
County of San Diego is considerably less dense, with large areas remaining completely
undeveloped. Vehicular access to tributaries becomes more limited as one gets farther upstream
from the reservoir. This inventory is limited to the following stream reaches: Otay River, Poggi
Canyon Creek, O’Neal Canyon Creek, Dulzura Creek, Proctor Valley Creek, Hollenbeck
Canyon Creek, and Jamul Creek.
Field Reconnaissance
The field reconnaissance was comprised of a combination of foot and vehicle over a multi-day
period. The most significant flood control structure observed was the Lower Otay Reservoir
Dam, which effectively splits the watershed into two pieces. The following discussion is broken
down into two major sections corresponding to areas upstream and downstream of the Lower
Otay Reservoir.
The attached map displays the observed flood management facilities, major stream reaches,
roads, and municipal boundaries. Incorporating the information into a GIS database allows it to
be viewed using ArcView. Pictures of some of the facilities are accessible within the GIS theme
enabling the user to view the pictures simply by clicking on the facility.
Otay River – Upstream of Lower Otay Reservoir
Dulzura Creek
Dulzura creek extends upstream from the Lower Otay Reservoir generally paralleling Otay
Lakes Road until reaching State Route 94 (SR-94). The creek then bends southeast to follow SR94, passing through the communities of Engineer Springs and Dulzura. This creek has few flood
control facilities and little adjacent development.
Immediately upstream of the reservoir, the creek passes under Otay Lakes Road in a triple box
culvert. Based on field observations it appears that this culvert may overtop and flood the road
during storm events. However, because the crossing occurs at a dip section of the road, flooding
appears localized. Upstream of this crossing, the creek parallels the road on the north side with
hilly terrain on both sides.
Approximately two miles upstream of the reservoir the creek passes through an RV Park. The
RV Park has constructed a culvert road crossing of the creek to facilitate access to the north side
of the creek. An abandoned crossing was observed approximately 50 yards downstream of the
existing crossing. The existing culvert consisted of four reinforced concrete pipes laid in the
creek. Upstream of the RV Park, the hilly terrain on the north side of the creek flattens out and
the creek passes through large areas of open, flat land before reaching State Route 94.
State Route 94 passes over the creek on an older 3-pier bridge. The creek then parallels SR 94
through the communities of Dulzura and Engineer Springs. During this reach, the creek crosses
under the highway once. A single pier bridge carries traffic from the south to north bank of the
creek near the Dulzura Post Office. While this section of the creek was more heavily developed
than the downstream reaches, development was sparse with limited impervious improvements.
While some small culvert crossings may exist in this area to facilitate access for private property
owners, no additional significant flood management facilities were observed.
Hollenbeck Canyon Creek
The Hollenbeck Canyon Creek headwaters exist near the intersection of Honey Springs Road
and Lyons Valley Road. Flows proceed downstream in a southwesterly direction towards a
junction with Dulzura Creek. The upstream creek reach runs alongside Lyons Valley Road with
only one visible flood management facility; a culvert crossing under Lyons Valley Road.
Development in the area consists of single-family homes on large lots interspaced with natural
open space. After a steep drop in elevation and another culvert crossing, the creek leaves the
rural residential area behind. There are no further flood control facilities until the creek reaches
SR 94.
The creek crosses under SR-94 in a culvert. After the crossing, flows return to a natural creek
channel and continue downstream until reaching a junction with Dulzura Creek. Other then the
three road crossings, no flood management facilities were visible.
Jamul Creek
Jamul Creek is a natural stream interrupted only by the SR 94 crossing. Similar to the
Hollenbeck Canyon Creek, Jamul Creek has its headwaters northeast of SR 94. Flows proceed
downstream in the natural creek until reaching SR 94. After passing through a culvert crossing,
flows continue downstream until eventually confluencing with Dulzura Creek. The area
adjoining this creek is largely undeveloped without improvements of any kind.
Proctor Valley Creek
Proctor Valley Creek represents the last tributary upstream of the reservoir examined as part of
this report. The creek has its headwaters in the Indian Springs area of San Diego County and
ultimately discharges into Upper Otay Reservoir. While some residences dot the area
surrounding the headwaters, the creek quickly draws away from the homes. A dirt road
paralleling the creek nearly all the way to reservoir allows access to the remaining creek reach
length. No facilities were visible.
An old spillway connects the Upper and Lower Otay Reservoirs. In the event the upper reservoir
overtops, flows will pass through the spillway and into the lower reservoir. The Lower Otay
Reservoir has a concrete manmade dam at its southern end and supplies potable water to the San
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Diego area. The western and southern shores of the lower reservoir encompass the ARCO
Olympic Training Center, two local parks, an open space preserve, and a water treatment plant.
Otay River – Downstream of Lower Otay Reservoir
O’Neal Canyon Creek
O’Neal Canyon Creek confluences with the Otay River immediately downstream of the Lower
Otay Reservoir dam. A short distance upstream of this confluence, O’Neal Canyon Creek passes
between the East and West Mesa Detention Facility (R.J. Donovan Correctional Facility). The
creek utilizes a culvert to pass through a significant embankment supporting the access road
connecting the East and West Detention Facilities. Given the steep bank slopes adjoining the
creek and the greater than 20-foot high road embankment, this culvert acts as a significant flood
management facility for this creek. Unfortunately, due to the presence of the Detention Facility
stopping along the road was illegal. Therefore, pictures of this culvert are unavailable.
Upstream of this culvert and the detention facility the creek runs through undeveloped land
inaccessible via automobile. No further flood management facilities were observed along this
reach.
Poggi Canyon Creek
Poggi Canyon Creek’s headwaters lie just south of Olympic Parkway and east of the proposed
State Route 125; the creek confluences with the Otay River immediately downstream of the
Interstate 805 bridge crossing. Existing development along the lower reaches of this creek
combined with new residential development along the creek’s upper reaches will completely
transform this stream to an urban creek over the next couple of years.
No facilities were visible along the upper reaches of this creek. However, the significant
residential development along Olympic Parkway in this area will include improvements to the
creek.
As the creek nears Highway 805, it enters a previously developed area of Chula Vista and
contains a number of flood control improvements. Near Valley Lindo Elementary, the creek uses
a large circular culvert to cross under streets and other improvements. Downstream of this
culvert, the creek is sometimes confined to a concrete channel extending under the Highway 805
Bridge crossing towards Main Street. At Main Street, the creek crosses under the road in a box
culvert and discharges into a creek channel lined with rock gabions to protect the side slopes.
Finally, the creek crosses under Rancho Drive via a 3-cell box culvert before confluencing with
Otay River.
Otay River
The Otay River flows from the Lower Otay Reservoir downstream through the cities of Chula
Vista, San Diego, and Imperial in addition to the County of San Diego. Between the Lower Otay
Reservoir dam and Heritage Road, the river passes through largely undeveloped terrain. No
facilities were observed in this area. Immediately downstream of the Heritage Road Bridge
crossing, lies the Coors Amphitheater. From this point on, the river runs through a developed
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corridor with a mix of residential, commercial, and industrial development. However, the river
retains a natural channel in this area and there are no visible flood control improvements. Upon
crossing under Highway 805, the river enters the Otay Valley Regional Park. This park acts as a
buffer between the river and adjoining development. The river retains a natural channel along
this reach with a number of bridge crossings. The channel is highly vegetated with sections of
riprap along the channel banks. After crossing under Highway 5, the river meanders through an
open field passing through a drop structure and under a pedestrian bridge. Downstream of the
pedestrian bridge, the river parallels the salt flats for a brief distance before discharging into the
southern portion of San Diego Bay.
Floodplain Compatible Uses Inventory
An inventory of land uses potential compatible with floodplain areas was completed for the Otay
watershed. Recreational uses is often a compatible use with few structures and residences.
Existing and proposed recreational land uses were mapped within the watershed and shown
relative to the FEMA 100-year floodplain boundaries. Recreational land uses included
neighborhood parks, regional parks, campgrounds, and open space preserves.
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