A bridge on Spicewood Springs Road in Northwest Austin that, according to Travis County documents, floods after “relatively brief rainfall events” will likely begin reconstruction by summer 2020.

Three reconstruction plans—which differ in construction cost, timeline and added detours—are up for public review and comment through May 9.

The bridge up for reconstruction, identified as Spicewood Springs Road Low-Water Crossing No. 1 in county documents, is located on Spicewood Springs approximately 0.5 miles north of Loop 360. Construction will elevate the new bridge and add two 5-foot-wide shoulders as well as 1-foot-wide guardrails.

Flooding in 2012 caused damage to the bridge that necessitated repairs, but repairs done on the bridge did not mitigate the chances for the bridge to overtop, according to Travis County Project Manager Mo Mortazavi.

“The flood waters basically washed off the surface of the bridge. [Travis County] just went ahead and put a new concrete surface on it,” Mortazavi said. “We did not improve the conveyance of the bridge. … We never made it any larger, and it still is, of course, prone to flooding.”

The low-water crossing was included in the voter-approved 2017 Travis County bond packages, with $3.83 million earmarked for the project.

REPLACEMENT PLANS


County officials and engineers presented alternative plans for the bridge replacement at an April 29 public meeting at the Spicewood Springs Branch Public Library located in Northwest Austin.

Three different plans were presented for public review and comment in addition to a no-build, or “do nothing,” alternative.

The first of the three alternatives would close the bridge entirely during the construction of a new nearby bridge. This plan is the cheapest of the construction options, costing an estimated $3.2 million.

A second alternative would partially close the existing low-water crossing while construction continues on the new elevated bridge. One lane of the crossing would remain open with temporary traffic controls, according to county documents. Traffic would then be shifted to the new one-lane bridge while the second lane is under construction.

However, that plan is expected to cost the most and take the longest to construct. Estimates show a $4.1 million cost in construction funds and an 11-month construction timeline.

Both the first and second options would require an approximately 5-mile detour to motorists’ routes, according to the proposed detour map shown by county officials at the April 29 meeting.



The third bridge replacement alternative outlines the construction of a new bridge in a separate location from the existing low-water crossing on Spicewood Springs. This would allow the current crossing to stay open while the new bridge is under construction, eliminating the need for a detour.

This option would require Travis County to purchase an additional right of way for the project, according to county documents. County officials expect this option to cost $3.6 million and take eight months to construct.

A timeline presented at the meeting showed the project is expected to enter preliminary design in May with a second community meeting likely to be held in August. Documents show the project is ultimately expected to begin construction in summer 2020.

Northwest Austin residents can submit comments on the bridge replacement options by mailing in written comments to Huitt-Zollars Inc., 3701 Executive Center Drive, Ste. 101, Austin. Comments will also be accepted via email at [email protected].

View the full list of documents made available at the April 29 public meeting below.