Water issues are on the rise

If you’ve been to Central Park recently, you’ve seen that water in Talbert Lake has risen nearly a foot over the past week. Rising groundwater may be the cause.

We talked to Jim Jones and Howard Johnson in the city’s Public Works Department, and they say that our groundwater basin is at capacity. Capacity is actually an arbitrary level set at negative 200,000 acre-feet, meaning that the groundwater basin can, in fact, hold an additional 200,000 acre-feet of water. As a comparison, before last year’s El Nino rains, the level was negative 500,000 acre-feet. Exactly why the lake level should be rising now in the absence of recent rain is unclear, especially since, according to Johnson, the groundwater level right now is 24 feet below Central Park.

Orange County has always been a land of water surplus and deficit. The first Mexican settlers found extensive spring-fed bogs in this area and streams that ran year-round. The Santa Ana River tumbled out of the San Bernardino Mountains through Santa Ana Canyon and meandered its way to the ocean through a naturally braided riverbed. But when it flooded, it was capable of covering the ground with a solid sheet of water from beach to foothills.

The flood of 1825 was so great that it changed the course of the river to near its present outfall between Huntington Beach and Newport Beach. During the flood of 1861-62, four weeks of rain created an inland sea with water 4 feet deep up to four miles away from the riverbed. A series of heavy rainstorms hit the coastal area again in 1938, causing extreme flooding. Ten inches of rain -- close to our annual rainfall -- fell in one day. An 8-foot-high wall of water roared out of Santa Ana Canyon and spread over the flood plain. The raging waters inundated an area 15 miles long and seven miles wide, claimed 19 lives, left 2,000 people homeless, washed out bridges and roads, and deposited a thick layer of alkaline silt and debris on thousands of acres of farmland.

There was either too much or too little water. Artesian wells were once common on the small, scattered ranches in Huntington Beach. The water table was so high during pioneer days that all a farmer needed to do was drive a pipe into the ground and water bubbled up. Cattle were replaced with water-demanding crops such as citrus, lima beans and celery. The population grew, people drilled more wells, and the ground water level dropped, drying up the artesian wells. The largely agricultural economy of the early 1900s siphoned off more than 200,000 acre-feet of groundwater annually, and the groundwater basin dropped by an average of 77 feet in some areas. Orange County was going dry.

The Santa Ana River was the main source for ground water replenishment, but it was carrying less water each year into Orange County due to upstream storage and development. The Orange County Water District formed in 1933 to regulate use of the groundwater basin.

Construction of Prado Dam in 1941 tamed the sometimesmighty river. Floodwater from the Santa Ana now is held temporarily behind Prado Dam in an extensive willow wetland and behind the newly constructed Seven Oaks dam east of San Bernardino. Water is released slowly so that it will percolate into the ground water basin to recharge it. That is what has been happening ever since the record-setting rainfall of last year.

Generally, the surface of the riverbed is dry downstream of Santa Ana and Anaheim until it comes under tidal influence. However, the water continues to flow underground, filling the vast underground reservoirs under Huntington Beach. Don’t picture an underground cavern filled with water. It’s more like a glass of sand with water poured into it.

Normally, the city of Huntington Beach pumps water out of its underground reservoirs to use for irrigation in Central Park. This year, it was more economically advantageous to use Metropolitan Water District water for irrigation, so the water tables remained high.

Presumably, when the water table is as high as it is now, the water percolates upward, filling Talbert and Sully Miller Lakes in Central Park and Blackbird Pond in Shipley Nature Center from below. These bodies of water are connected hydrologically. When one goes up, they all go up. The inner trails at Shipley Nature Center are now all flooded, including portions of the main outer trail. This has necessitated reworking the trails.

The days of disastrous flooding may not be all behind us. Low-lying areas of Central Park are designed as flood retention basins. If the water level in Talbert Lake gets too high, the water flows into the Slater Flood Control channel. If the water in the Slater Flood Control Channel gets too high, it spills over into Shipley Nature Center instead of flooding nearby homes. But that raises the level in Talbert Lake. There is only so much water that Central Park can hold.

Residents in low-lying areas would do well to keep their eyes on a tide chart and weather forecasts. Floodwater can’t flow against the force of a high tide. It moves up-channel with the tide. With the ground water basin full, flood-control channels will back up if storms and high tides coincide. If you live on a flood plain, you should be prepared for the worst.

* VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and environmentalists. They can be reached at vicleipzig@aol.com.

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