[quote author="bkshopr" date=1249446688]On a piece of unimproved land rainfall percolate through the soil. When new suburbs are built up to 80% of the soil is covered by concrete and other improvements. The run off is captured by catch basin and temporarily stored in dedicated retention basins allowing the water to slowly drain to the flood channels such as the San Diego Creek and other tributaries that drain to the ocean.
The major flood channels are between West Irvine and Northpark, San Diego Creek adjacent to Oakcreek and the channel that lead to the Back Bay. The flood channels are the lifeline of a master planned community and this infrastructure is mandatory.
The path adjacent to the channel is required for service vehicle as well as emergency fire and rescue vehicles in case of drowning victim during the heavy rain and other accidents that might occur year round. These existing mandatory paths represent a majority of the Mountain to the Sea trail in the city sector. They have been there for years before the concept.
Missing links were paved to create full continuity. The trail at the wilderness portion of the Ranch is a gravel path not opened to the public without an appointment with a docent. Very little land was given up for this wonderful amenity.</blockquote>
Agua Chinon is a stream that flows down Limestone Canyon and into the San Diego Creek and finally to the Santa Ana River to the back bay. Since the 1940s, the Agua Chinon has been buried in a concrete pipe under the El Toro runways. The Great Park plan calls for the Agua Chinon to be brought to the surface following the demo of the runways. The restored Agua Chinon creek will be part of a wildlife corridor / nature area that will be a major feature of the Great Park. Now if only Lennar can get the funds to start work.