🔍 Key Concepts

• Low Water Reference Plane (LWRP) on Western Rivers bridge clearances • How published vertical clearances are referenced to a specific river stage or datum • Difference between eastbound/westbound spans and making sure you read the correct line in the bridge table

💭 Think About

• On the river chart or reference table, find the Natchez-Vidalia Highway Bridge and identify how the vertical clearance is defined relative to the Low Water Reference Plane (LWRP). What does it say about the clearance "at" LWRP? • Since the river level is stated to be the same as the LWRP (6.5 ft), do you need to add or subtract anything from the published clearance, or do you use the listed value directly? • Make sure you are looking at the westbound span data only. How does that number compare to the multiple‑choice options?

✅ Before You Answer

• Verify you are using the correct bridge name and location (Natchez-Vidalia Highway Bridge, westbound). • Confirm from the table how vertical clearance is stated: "X feet above LWRP" or at a specific stage. At LWRP, you should match that stated value directly. • Double-check you are not mixing horizontal clearance with vertical clearance, and that you are reading the correct column for the westbound span before matching to the answer choices.