Enchanted Hills Dam maintenance

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This project was complete the beginning of January 2017.

Northeast corner looking south at the outlet pre-construction-showing ponding where invasive species took over limiting infiltration

Enchanted Hills Dam was constructed in 2002, for the protection of NM528 to reduce the flow of stormwater coming off of the upstream area. The area above the dam has 3 ponds and 2 channels that discharge to the dam. An invasive plant species inhibited water infiltration into the flood pool area which allowed the sediment to remain in a liquefied state. Once the plant barrier was established, the subsequent water flows pushed the liquefied sediment up the northern slope reducing the design capacity of the dam. Bringing the dam back to design capacity required removing almost 15,000 cubic yards of sediment. 15,000 cubic yards is the equivalent of nearly 10,000 tons or 10,000 full grown polar bears or 1,430 full grown African elephants or almost 70 full grown Blue whales (which is quite a bit of sediment). The sediment was transported to the Waste Management landfill to be used as cover as required by federal regulations to protect the community. This joint cooperation between local government and big business resulted in a mutually beneficial project which reduced the cost of hauling and disposing of the excavated sediment by SSCAFCA while Waste Management repurposed the sediment.

 

Looking Northeast from outlet-showing staking for sediment removal


Looking south along the dam berm

 

 

Post construction showing North slope returned to design

Looking east along the low flow channel to the ported riser outlet

Looking north along the eastern toe showing the removal of invasive plant species

Looking west along the low flow showing the removed berm

Looking west along the low flow showing the removed berm