Ann W. Richards Congress Avenue Bridge

Ann W. Richards Congress Avenue Bridge
Official name	Ann W. Richards Congress Avenue Bridge
Other name(s)	Congress Avenue Bridge South Congress Avenue Bridge
Carries	Motor vehicles, pedestrians, and bicycles
Crosses	Lady Bird Lake
Locale	Austin, Texas
Maintained by	City of Austin
ID number	TXNBI 142270B00425007
Design	Arch bridge
Material	concrete
Total length	945.9 feet (288.3 m)
Width	60 feet (18 m)
Longest span	119.1 feet (36.3 m)
Opened	April 4, 1910
Toll	Free both ways
Coordinates	30°15′41″N 97°44′43″W / 30.26126°N 97.74531°W / 30.26126; -97.74531Coordinates: 30°15′41″N 97°44′43″W / 30.26126°N 97.74531°W / 30.26126; -97.74531

The Ann W. Richards Congress Avenue Bridge (formerly known simply as the Congress Avenue Bridge) crosses over Lady Bird Lake in Austin, Texas. Before the construction of Longhorn Dam was completed in 1960, the bridge crossed the Colorado River from which Lady Bird Lake is impounded. The bridge was known as the Congress Avenue Bridge from the construction of the first span across the Colorado River at that location in the late 19th century until November 16, 2006, when the Austin City Council renamed the current bridge in honor of the late Ann W. Richards, the 45th Governor of Texas and Austin resident. The bridge is a concrete arch bridge, with three southbound and three northbound vehicle lanes and sidewalks on both sides of the bridge.

The bridge is currently home to the world's largest urban bat colony.

History

The bridge at dusk.

The first bridge across the Colorado River in this location was constructed in 1869 or 1871. The original structure was a pontoon toll bridge. In 1875, a new wooden toll bridge was constructed across the river. The bridge’s construction was finished at a cost of $80,000.00; an additional $20,000.00 was used to macadamize dykes across lowlands and a culvert over Bouldin Branch. On one occasion, a herd of cattle caused a span fifty feet above the water to give way. Only a few cattle were rescued.

On January 22, 1884, a modern iron bridge funded by private interests was opened at a cost of $74,000.00. There were sufficient spans to allow for the highest stage of over-flow when the river flooded. The bridge was designed and built by engineer C.Q. Horton. The bridge was purchased by the Travis County Road and Bridge Co. and the City of Austin on June 18, 1886. By 1891, the Travis County Road and Bridge Co. refused to care for the bridge, and Travis County Commissioners negotiated an agreement whereby the City of Austin assumed complete control of the bridge's operation. The city was forced to repair the bridge in 1892 and again in 1897, when the city paid half the cost for re-flooring, a task that took until 1901 to complete. The bridge was repainted in 1902.

By 1908, traffic across the bridge had increased to the point where a new bridge was needed. Plans for a new concrete arch bridge were drawn as follows: "New Bridge: 910 FT Long iron bridge; 6 spans { 5-150FT Long, 1-160, 27 FT. Tall, 18 FT. Roadway, Bridge Piers are 45 FT. above ground. Will be built by King Bridge Co. of Cleveland, Ohio. Strength: 2,000 LBS per FT. – But was built four times as strong".^{[citation needed]} The new bridge was opened on April 4, 1910, at a final cost of $208,950.10. Sections of the old iron bridge were later used in 1915 and 1922 to rebuild the bridge at nearby Moore's Crossing.

The bridge was rehabilitated in 1980.^[1]

On November 16, 2006, the Austin City Council renamed the bridge the Ann W. Richards Congress Avenue Bridge at its weekly meeting.^[2] The late Governor of Texas was also a part-time Austin resident and former Travis County Commissioner.

Bats

Bridge Bats from Below

Tourists waiting for the bats.

The emergence of the bats.

The bridge bats have become an integral part of Austin's cultural identity.

Ann W. Richards Congress Avenue Bridge is home to the world's largest urban bat colony, which is composed of Mexican Free-tailed Bats. The bats reside beneath the road deck in gaps between the concrete component structures. They are migratory, spending their summers in Austin and the winters in Mexico. According to Bat Conservation International,^[3] between 750,000 and 1.5 million bats reside underneath the bridge each summer. Since Austin's human population is about 750,000, there are more bats than people in Austin during the summer.

The nightly emergence of the bats from underneath the bridge at dusk, and their flight across Lady Bird Lake primarily to the east, to feed themselves, attracts as many as 100,000 tourists annually.^[3] Tourists can see the bats from the bridge, from the sides of the river and even from special boats.

A study made in 1999 by Dr Gail R. Ryser and Roxana Popovici concludes that the economic impact of the bats to Austin city is $7.9 million each year. Today, businesses are using the bats as a symbol for Austin.

A project, called "Bats and Bridges", has been put in place by the Texas Department of Transportation, in cooperation with BCI, to study the best way to make bridges habitable for bats.

See also

Austin portal

• List of crossings of the Colorado River

References

1. ^ "Bridgehunter.com - South Congress Avenue Bridge". http://bridgehunter.com/tx/travis/142270B00425007/. Retrieved June 14, 2011. 
2. ^ "20061116-040, Agenda Late Backup". November 16, 2006. http://www.ci.austin.tx.us/edims/document.cfm?id=99219. Retrieved June 14, 2011. 
3. ^ ^{a b} Bat Conservation International, History of the Congress Avenue Bridge bats

External links

• ARKive - images and movies of the Brazilian free-tailed bat (Tadarida brasiliensis)
• Bat Conservation International website
• Mexican Bats Find Cross-Border Benefactors (Washington Post)
• Bat Conservation International webpage about Mexican free-tailed bats
• BatCon Webpage about Congress Avenue Bridge and its bats.