Browse
Search
Agenda - 04-22-1986
OrangeCountyNC
>
Board of County Commissioners
>
BOCC Agendas
>
1980's
>
1986
>
Agenda - 04-22-1986
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
10/10/2016 12:28:10 PM
Creation date
9/20/2016 4:46:57 PM
Metadata
Fields
Template:
BOCC
Date
4/22/1986
Meeting Type
Regular Meeting
Document Type
Agenda
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
150
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
View images
View plain text
05e <br /> Existing stormwater runoff into proposed detention structure is as <br /> follows: <br /> Existing Impervious Surface Area = 0.25 Acres <br /> Runoff Coeff. = 0.95 <br /> Intensity of Rain = 7.5 in./hr. <br /> 0 = 1.8 cfs <br /> Existing Grass and Woodland = 5.15 Acres <br /> Runoff Coeff. = 0.5 <br /> Intensity of Rain = 7.5 in./hr. <br /> G = 19.5 cfs <br /> Total stormwater runoff into proposed detention structure after <br /> development is as follows: <br /> Additional Impervious Surface = 0.42 Acres <br /> Total Impervious Surface <br /> Runoff Coeff. 0.67 Acres. <br /> 0.95 <br /> Intensity of Rain <br /> 7.5 in./hr. <br /> Q = 4.8 cfs <br /> Remaining Grass and Woodland = 4.73 Acres <br /> Runoff Coeff. = 0.5 <br /> Intensity of Rain = 7.5 in./hr. <br /> U = 17.9 cfs <br /> The total quantity of stormwater runoff flowing into the proposed <br /> detention structure before development is 21.3 cfs. After <br /> development the stormwater runoff into this area is 22.7 cfs. The <br /> difference in runoff ( Q) is 1.4 cfs. The storage for the <br /> detention structure is computed by using the formula: <br /> Storage = ( 0) 2 (Tc) (60 sec/min) <br /> ( Q) = 1.4 cfm <br /> Tc = 3.7 minutes <br /> Storage = 621.6 cubic feet <br /> A small stilling basin will be used as the stormwater detention <br /> structure (see Exhibit 1 and 2). This basin will have a 22' <br /> controlled discharge of the stormwater. The stilling basin, <br /> located as it is in an area which has almost no grade held several <br /> times the minimum storage (621.6 cubic feet) . The stilling basin <br /> will slow down and detain runoff from this site. This will allow <br /> the pollutants to settle. The stormwater passing through rock dem <br /> section (see Exhibit 2) will provide further cleansing of <br /> pollutants by filtration. <br /> 2 <br />
The URL can be used to link to this page
Your browser does not support the video tag.