Lemon Grove, California

Regular maintenance ensures effectiveness of drainage infrastructure

For decades, Federal Boulevard in San Diego County, California endured flooding that forced road closures and blocked access to homes and businesses during even moderately heavy rains. Following a record flood in 1995, the city secured a FEMA grant to build 1,700 ft of reinforced concrete pipes to draw water away from the road into storm drains. Now the road rarely floods, and adjacent homes and businesses are better protected from lingering floodwaters.

Photo by Dave Gatley - FEMA

Community facts

Population
26,709
Homes
8,868
Businesses
2,049
Source: US Census Bureau.

Mitigation actions

The infrastructure was designed to contain runoff from a 100-year rainfall event for up to 20 years. Although the road still floods occasionally, there are far fewer road closures and adjacent homes and businesses are rarely affected. Fewer road closures mean that businesses can continue to operate during heavy rains and fewer resources are spent rerouting traffic and rescuing stranded motorists.

While local funds covered 25% of the project's cost, FEMA's Hazard Mitigation Grant Program covered the remaining 75%, which made funding less of a challenge for the community. The road is a major thoroughfare in the city. By keeping it open during heavy rains, the city is able to ensure that local businesses and workers do not lose vital customers, revenue and wages. It is estimated that in 2007, the area avoided approximately $220,500 in lost business income and wages.

Benefits of mitigation

Economic benefits
$731,144
Total monetized benefits
Return on investment
17.6%
Estimated return on investment
Benefit-cost ratio
1.2
Benefit-cost ratio of the Lemon Grove project
Source: Federal Emergency Management Agency (2007). Loss Avoidance Study, Southern California Flood Control Mitigation.

Project challenges

Repeat flooding on the throughway remains a challenge

Federal Boulevard still has issues. The road floods one to three times per year, although businesses are rarely affected. And the city now posts warning signs and preemptively closes the road when heavy rain is expected.

“Making sure Federal Boulevard is a clear and safe route for folks to travel on is probably the biggest benefit of staying up to date on our maintenance plan”
Mike James, public works director, City of Lemon Grove

Future considerations

Flood victims Jim and Millie Lyberger lost their home, possessions and tools when the levee broke and flooded their house and surrounding homes.
Photo by flood mitigation staff - FEMA
Vegetation growth and debris can clog infrastructure, requiring regular maintenance to promote drainage

Although Federal Boulevard still floods, businesses are generally unaffected. To minimize the risk of floods, the public works team conducts regular assessments of the drainage infrastructure and schedules maintenance one to four times per year to clear debris and vegetation growth that could otherwise reduce drainage capacity.

They also educate nearby business owners about the importance of maintaining storm drains and doing pre-winter clean-outs so water can move freely off their properties. “Otherwise, it's 'out of sight, out of mind' until something goes wrong,” says Mike James, director of public works in Lemon Grove.

Flood mitigation resources

Below is a non-exhaustive list of other flood mitigation information resources.