Talk:Upper Newport Bay

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The Upper Newport Bay is thought to have formed 300,000 years ago when sea levels were lower than they are now due to a glacial period. At that time, geologists estimate that this area received about 80 inches of rain a year. This likely produced year-round flow in the ancient Santa Ana River that flowed through the channel below you and southward beneath Upper Newport Bay.

At that time, the river would have flowed though a flat flood plain. Had any of the hills you see around you today existed, the river would have taken a different course. After the river had eroded out a stable course, the Newport Mesa and San Joaquin Hills began to slowly uplift as a result of movement along the Newport-Inglewood fault zone. Flow in ancient Santa Ana River was able to maintain its course throughout the uplift by eroding the land faster than it was uplifted. This resulted in the steep cliffs you see surrounding the bay, such as the 100 foot cliffs across the bay to the east.

Rising sea levels completely submerged the bay until about 15,000 to 25,000 years ago. This submersion effectively stopped the continued erosion of the river channel as the Newport Mesa continued to rise. While the bay was submerged, the ancient Santa Ana River also found a new path emptying into the ocean at Alamitos Bay.

Recent lining of the creeks that continue to drain into the Upper Newport Bay has resulted in the filling in of the bay with more sediment than would be expected in a natural system. As a result the bay has been dredged to maintain its current configuration.

Filling in of bays is a natural process, but not at the rate that had been observed in the years since the area was urbanized. Natural processes would eventually fill in the bay, turning it into a marsh, then open grass land if allowed to continue.

http://www.geocaching.com/seek/cache_details.aspx?guid=93f775aa-17ed-4a89-bb67-284f82cda44d

Additional History

Both the Upper Bay (locally referred to as the "Back Bay") and Newport Bay proper were originally formed by the Santa Ana River. The river's natural course was diverted to where it now flows between the city boundaries of Newport Beach and Huntington Beach. When the river was diverted (year???), the "Back Bay" began to silt up to a backwater estuary.

At one point, there was a salt works there, until the great flood (30's?) wiped it out, although the dikes and some cement fixtures can still be seen. As late as the 60's, cow carcasses from the Irvine ranch, and oranges from groves, would wash down the upper bay into Newport Bay.

Different approaches to the process of silting have been implemented over the decades. In the 60's, the back bay was kept dredged to allow for water skiing. In the '70's, it was recognized as a significant element of the migratory pathway for birds along the West Coast, and a laissez faire approach was implemented, allowing a "natural" process. However, as there was no longer a river to keep the channel free, the silt stopped the "breathing" of Newport Bay, the flow of fresh sea water, oxygen and nutrients into that environment, and the outflow of pollutants, and the once diverse ecosystem of Newport Bay largely collapsed. Over the later years of the 70's and the 80's, with eco-conscious groups like SPON (Stop Polluting Our Newport), dredging was re-established, and a balance was attained. Today, life forms such as octopus are begining to reappear in the bay, signaling a return to a more healthy ecosystem.

(Sorry, no documentation/citations for this, but if someone wants, I know it's not hard to find. I did my "book reports" long ago, and don't have the time currently to redo them, sorry.) (Cuchulainshound (talk) 01:32, 25 November 2007 (UTC))