20051457 Ver 1_Emails_20071126

[Fwd: First Broad River Reservoir Study]
Subject: [Fwd: First Broad River Reservoir Study]
From: Alan Johnson <[e-mail]>
Date: Mon, 26 Nov 2007 09:52:24 -0500
To: Cyndi Karoly <[e-mail]>
FYI
Alan Johnson - Alan.JohnsonCncmail.net
North Carolina Dept. of Environment & Natural Resources
Div. of Water Quality
610 E. Center Ave., Suite 301
Mooresville, NC 28115
Ph: [phone] Fax: [phone]
Subject: First Broad River Reservoir Study
From: "Keith Webb" <[e-mail]>
Date: Wed, 21 Nov 2007 16:56:02 -0500
To: <[e-mail]>
CC: "Henry Wicker " <[e-mail]>, <[e-mail]>,
<[e-mail]>, <[e-mail]>, <[e-mail]>,
<[e-mail]>, <[e-mail]>
Brian:
The following is a summary of my conclusions from the web conference on Monday and action items that need to
be addresses from the modeling stand point.
Action Item #1
Flow Gauge
The question was raised why we used the stream flow information from the First Broad River USGS gauge near
Casar for the model. Why not use the information from the now abandon gauge on the First Broad River USGS
gauge near Lawndale.
The following is the information I could find on these two gauges:
First Broad River USGS gauge near Casar
Latitude 35°29'35", Longitude 81°40'56" NAD83
Cleveland County, North Carolina , Hydrologic Unit 03050105
USGS 02152100 FIRST BROAD RIVER NEAR CASAR, NC
Drainage area: 60.5 square miles
Data Type Begin Date End Date
Annual Statistics
Discharge, cubic feet per second 1959 2006
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[Fwd: First Broad River Reservoir Study]
First Broad River USGS gauge near Lawndale
USGS 02152500 FIRST BROAD RIVER NEAR LAWNDALE, NC
Latitude 35°22'50", Longitude 81°32'40" NAD27
Cleveland County, North Carolina , Hydrologic Unit 03050105
Drainage area: 200.00 square miles
AVAILABLE DATA:
Data Type' Begin Date End Date
Annual Statistics
Discharge, cubic feet per second 1940 1972
It is my understanding that we used the Casar gauge since it provided up to date stream flow information for the
past 47 years.
Can we compare our ratio flow at the dam site to historical flow numbers from the Lawndale gauge to compare
the two flows?
Will this resolve the issue of stream flows used for the model?
Action Item #2
Minimum In-stream flows
The model runs to date have been run assuming a minimum in-stream flow of 25 cfs below the proposed dam
location. During our web conference Jim Mead (DWR) pointed out that the DWR in-stream flow study
completed in the early 1990's for the First Broad River for by the Cleveland County Sanitary District (CCSD)
and the City of Shelby recommended a minimum in-stream flow of 70 cfs below the CCSD intake. It was my
understand from the discussions that the in-stream flow needs where much higher at the CCSD intake site than
those at the City of Shelby intake site due to stream habitat and selected species.
With this in mind it would seem appropriate to re-run the model scenarios using the 70 cfs at this time.
There was discussion about DWR performing new modeling to determine the exact minimum in-stream flow. I
understood that this could take a number of months to complete?
For the point we are in the process it would seem that modeling the various scenarios for a minimum in-stream
flow of 70 cfs would be appropriate?
What are your thoughts?
Using the 70 cfs would provide a good understanding if the various alternatives are feasible.
Action Item #3
Historical flow records and number of days when adequate water was not available to meet potable water
demands
We discussed the model scenario previously prepared in which we model the First Broad River with no
impoundments. The model if I understand the parameters, will indicate the total number of days when demand
would not have been met based upon historical records.
It would seem to be appropriate to run this model and if possible expand the input flows to include the data set
for the Lawndale gauge so that the modeling period extends back to 1940.
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[Fwd: First Broad River Reservoir Study]
I would recommend running the model for the following criteria:
In-stream flow demand 70 cfs at CCSD site
CCSD demand one run at 5.0 MGD (current peak demand) and 8.8 MGD projected future demand
City of Shelby demand 12.0 MGD
Will this model run not give us the number of days when based upon historical flow records demands were not
met at CCSD?
Can it also indicate the number of days when demands were not available at the Shelby intake?
Action Item #4
New modeling results
We have three (3) alternatives at the current time as follows:
First Broad River Reservoir
Knob Creek Reservoir
Crooked Run Creek Reservoir
With the new higher in-stream flow number I think we should re-run the model for these three alternatives using
the 70 cfs minimum in-stream flow for the First Broad River below the proposed dam site or the existing CCSD
intake. The alternatives and assumptions are:
1. First Broad Reservoir
CCSD demand 8.80 MGD
City of Shelby demand 12.0 MGD
Minimum in-stream flow below dam for First Broad River 70 cfs.
Water released from reservoir to meet in-stream demands and Shelby demands first, then meet
CCSD demands.
Using this set of criteria run the model to determine the safe yield of the reservoir with full pool at
860 and low pool at 840.
2. Knob Creek Reservoir
CCSD demand 8.80 MGD
City of Shelby demand 12.0 MGD
Minimum in-stream flow below existing CCSD intake for First Broad River 70 cfs.
Minimum in-stream flow below existing proposed Knob Creek Reservoir of 11 cfs.
Water released from reservoir plus natural in-stream flow in the First Broad River to meet
in-stream demands and Shelby demands first, then meet CCSD demands.
Utilize the existing CCSD intake and pump station (10 MGD capacity) to pump water from the
First Broad River to the Knob Creek Reservoir when excess flow conditions exist in the First
Broad River.
Using this set of criteria run the model to determine the safe yield of the reservoir with full pool at
860 and low pool at 840.
3. Crooked Run Creek Reservoir
CCSD demand 8.80 MGD
City of Shelby demand 12.0 MGD
Minimum in-stream flow below existing CCSD intake for First Broad River 70 cfs.
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[Fwd: First Broad River Reservoir Study]
Minimum in-stream flow below existing proposed Crooked Run Creek Reservoir of 3 cfs.
Water released from Crooked Run Creek Reservoir to meet the in-stream demands and CCSD
demands. only
Utilize the existing CCSD intake and pump station with upgrade in capacity to 15 MGD, to pump
water from the First Broad River to the Crooked Run Creek Reservoir when excess flow conditions
exist in the First Broad River.
Using this set of criteria run the model to determine the safe yield of the reservoir with full pool at
960 and low pool at 940.
rr?
mGf
"Building Partnerships by Providing Superior Service with Professional Integrity"
M. Keith Webb, P.E.
Vice President
McGill Associates, P.A.
55 Broad Street
Asheville, North Carolina 28801
[phone]
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