As we look at our creeks and waterways we see exotic weeds clogging the channels, replacing attractive trees such as sycamore and willow. We see rusty abandoned shopping carts and trash to highlight their lack of care. Yet the small streams and rivers that flow through San Diego are critical for storm water drainage. If we repaired and restored them, we could enhance the quality of urban life, save money, reduce the cost of public health problems, reduce flood risk and damage, and maximize the economic and ecological benefits of the services they provide. If they remain ignored and unloved, we can expect extremely costly damage will occur.

s we watch the strongest hurricane ever seen by scientists in the eastern Pacific dissipate, we should pause and reflect on the flood history of San Diego. It hasn't happened recently or often, but floods do occur and some are big. This information may be surprising for the homeowners and businessmen who have recently moved to the city and live and work in the flood plains. If flood damage does occur, who pays? The taxpayers of San Diego and the nation not the people who made it happen.

The San Diego River only reached a third this size, but at 94,500 cfs (which would completely fill Qualcomm stadium every couple of minutes) it was an awesome flood. The smaller flood of 1916 was also impressive and did considerable damage. Even the 1927 flood was significant, and it is worth noting that the last long dry spell like the current one occurred in 1927.

The San Diego River watershed covers a large area. In the past, when it was less urbanized than today, the San Diego River experienced several very large floods and many minor ones. Mission Valley was often full, bank to bank, and cut off all travel for several days at a time. The heavy rains of 1862 inundated most of California and filled much of the Central Valley. The heavy rains and overgrazed hills led to massive floods that flushed out the creeks and rivers of Southern California. The Santa Ana River peaked at 317,000 cfs (cubic feet per second; a cubic foot is about 8 gallons). This is more than 7 times the volume of the recent flood generated on the Colorado River to scour the river and create new sand bars.