A full Lake Travis from the Iguana Grill

Anyone who knows the lakes understands the title of this post.  Last October, Lake Travis was just over 50 feet low.  The area that drains into the lake had been in an exceptional drought for a very long time.  Then the rain came.  It wasn't anything exceptional, but a lot of rain fell across a large geographic area and it fell often.  This filled creeks and rivers and also underground aquifers that forced water out of springs that also filled creeks and rivers.

The geography and geology of the area that drains into the Central Texas Highland Lakes  is pretty interesting.  If you look at the Lower Colorado River Authority’s (LCRA) Hydromet,  you will see the geographic area that drains into the Highland Lakes.  Rivers that drain into the lakes include the Colorado, Concho, Llano, San Saba and Pedernales.  Many creeks and springs flow into these rivers.

Out west toward and beyond Lake Buchanan, there is a lot of granite.  The geology closer to Lake Travis is comprised mainly of limestone, much of which is very porous.  If rain over the area falls very quickly, some of it penetrates the surface and goes into underground aquifers, but most of it runs off into creeks and rivers.  If it falls more slowly, it tends to fill the aquifers.

Heavy rain tends to fill the lakes.  Slow falling rain, especially over a large area, helps fill underground aquifers.  As the water moves slowly under the ground, it makes its way out via many springs.  These springs steadily fill creeks, which feed rivers and these rivers fill the lakes.  The rains we have had over the last 5 months have been over a large enough area and have been steady enough to fill area lakes.  At 681 feet above mean sea level, LCRA states is at its full level.

This is great news for anyone who uses Lake Travis for recreational purposes and anyone with waterfront or lake view homes, but the LCRA probably isn’t thrilled.  The LCRA, which manages the Highland Lakes, doesn’t’ like Lake Travis to be full as we come into spring.  That is because Lake Travis is the primary flood control lake among the Highland Lakes.  Spring is when our area tends to get heavy rain.  If Lake Travis is full this time of year and we get heavy rain, flooding is likely.

Having said that, I have a feeling that area residents and visitors would rather see Lake Travis at 681 than 630.