We drove from Portland to Nevada, and we stopped to check out Pyramid Lake. This is one of two piluvial lakes in the country. There is only input, no surface output. Water only leaves through evaporation. It was formed by glaciation, and it used to be at a much higher level. Pyramid Lake is considered a paleolake, meaning it was not formed under the current hydrological conditions. There are springs beneath the lake that deposit calcium, which form "tufas" that look like little islands in the lake. (They used to be underwater!) Pyramid lake was really cool looking, especially on such a foggy weird day outside.
Next we drove to Lake Tahoe. It's raining! Apparently this is very unusual. I think we must have brought the rain with us. Too bad, I was looking forward to checking out the scenery. (We're sitting at an outside bar, by the way, to have a class lol.)
Lake Tahoe is extremely large and extremely deep, which is very unique and makes it a great opportunity for research. It is 1700 ft deep, and it is the deepest crater lake in the Sierras. Lake Tahoe is known for its remarkable clarity; it measured roughly 100 ft in the 1960's. During the 1960's to 1970's, development in Tahoe and it became very popular. The water quality at the lake started to go down and tension started because the wealthier people who lived here kept it clean and the working class people didn't.
The state line between California and Nevada rests in the center of Lake Tahoe, which makes it hard to manage. The Tahoe Regional Planning Authority (TRPA) managed the Tahoe basin in 1969, and they started to notice excess nutrients and an alarming decline in clarity. California was also concerned because they had lots of houses on their side of the lake. Nevada didn't seem to care are much because they were more focused on casinos and offroading. The TRPA made restrictions on development to preserve space so that water could percolate down into the ground instead of running off into the lake. This caused uproar because it significantly reduces property values and some were even restricted to 1% of their property. The TRPA also started a moratory of no development in the basin for two years (1990s) to do research and find solutions.The TRPA stepped in about jetskis and compromised on only allowing jetskis in certain places and certain times, and they have to be a 4-stroke.
The Lake Tahoe watershed management plan identified sources of impairments, what you need to reduce them and a timeline for reduction. The watershed management plan also has an educational component as well as milestones and a monitoring plan. This watershed management plan cost $10 million, which is extraordinary. Through the watershed management plan, they came up with a maximum amount of each impairment that is allowed in the waterbody. This is called a total daily maximum load (TMDL). There are 4000 TMDLs, and the biggest impairment is clarity. Lake Tahoe has the highest standard for clarity, at 97 feet. Currently, the clarity depth is about 67 ft. One of the biggest contributors is actually sediment deposited from the air, which was surprising to me. I really wish that it wasn't raining because I was really looking forward to seeing Lake Tahoe. I hope I get to come back some day! After our talk, we drove up to the town square and had a couple hours to do what we wanted. We did a little shopping and then had an appetizer at the Fire and Ice Bar. Then a few of us went to Harrah's to go gamble. I learned (kind of) how to play craps with Lucia and I won $10! It was a good day. Tonight we are staying in the Grand Sierra Resort in Reno, NV. The hotel was absolutely beautiful. It had a casino, too. We went in the pool and the hot tub first, of course. It was a great night. (Pictures coming soon)
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