Fish Movement Flow Requirements Study

Project Name: Saluda Hydroelectric Project

Summary: Determining minimum flow requirements for zone of passage

Client: South Carolina Electric & Gas Company

Project Location: Columbia, SC

Project Size: 203 MW

Services Provided:
•  IFIM
•  GIS Database Design and
    Management
•  Hydraulic and Hydrologic Analysis
•  Stakeholder Facilitation


Project Timeframe:
2007 - 2009

Relationship with Client: Since 1988

Client Needs:
South Carolina Electric & Gas Company (SCE&G) required determination of minimum flow requirements for fish passage at the Millrace Rapids on the lower Saluda River as part of the relicensing their Saluda Hydroelectric Project in Columbia, SC. These rapids were formed from steep ledges and featured complex channel hydraulics that could not be modeled using conventional methods.
 
Kleinschmidt Solution:
Kleinschmidt constructed a digital three-dimensional model using GIS that combined empirically collected geomorphologic and hydraulic data. Baseline data collection included spatially referenced elevation stations covering the entire “zones of passage” using sub-meter accurate GPS. The zones of passage represent the portions of the river available for fish to travel upstream at a given flow. These stations were then used to create a three-dimensional river bed profile using GIS. Working closely with SCE&G and relicensing stakeholders, a series of river flows were released and the water surface elevation was surveyed for each flow. These water surface measurements were then used to create a second three-dimensional surface representing the water cascading over the rapids. Utilizing these two features, Kleinschmidt was able to calculate and identify areas suitable for fish passage at differing flows based on bathymetery, water depths, and species.
 
Client Benefits:
Kleinschmidt’s unique approach allowed the client to successfully address fish passage concerns by demonstrating that lower minimum flows provided the necessary zone of passage criterion established in the South Carolina In-stream Flow Policy. By demonstrating compliance with the Legislative policy, SCE&G retained operational flexibility and secured the project mission as a reserve generating facility.