The scour evaluation guidance for new bridges with known foundation also applies to existing bridges with known foundations.

In certain cases, existing bridges with known foundations may be evaluated for potential scour using the following:

Texas Secondary Evaluation and Analysis for Scour
(TSEAS, 1993)

The TSEAS Manual includes two parts: a) Secondary Screening Method; and b) Concise Analysis Method. The Secondary Screening Method is only applicable to low volume Off-System bridges with known foundations. The Concise Analysis Method is applicable to both On-System and Off-System bridges that are not on the interstate system or are otherwise high priority bridges. Bridges that would be considered high priority are:

Bridges on principal arterials;Bridges on evacuation routes;
Bridges that provide access to local emergency services such as hospitals; and
Bridges that are defined as critical in a local emergency plan (i.e., bridges that enable immediate emergency response to disasters).

Upon completion of a scour evaluation for an existing bridge, the (Form 2605) is required to be completed and entered into the bridge inspection system, along with scour evaluation documentation. In addition, the results of the scour evaluation are to be used to determine the Bridge Inspection Coding for Item 113 – Scour. The results of the coding need to be entered into the BIMS.