§ 158.08 REQUIRED SUPPORTING MATERIAL FOR CONSTRUCTION PLANS.

   (A)   Materials. The following materials are required:

      (1)   Surface runoff flow patterns for all lots;

      (2)   All gutter flow patterns and depths at the design flow;

      (3)   Inlet capacities for all grates and curb inlets; summation in tabular form, for the minor system, the flow quantities intercepted by inlets and the flow quantities bypassed to the next inlet;

      (4)   Hydrographs for predevelopment and postdevelopment states. Both hydrographs are necessary for each subcatchment, at all collection points on the major system and at the outlet on major system;

      (5)   Hydraulic grade on the minor system;

      (6)   Critical depth and normal depth shall be reported for all channels and conduits;

      (7)   All areas where erosion may be a problem shall be noted on the plans;

      (8)   Inflow and outflow - hydrographs shall be furnished for all detention points in the subdivision; and

      (9)   A division location map showing the topography and ridge lines is required for predevelopment and postdevelopment. Hydrograph calculations shall correspond to this map.

   (B)   Additional information. Additional Information: Figures IV through VII outlining specifications for canals and dredge channels shall be on file and available for inspection in the office of the City Clerk.

   Figure VIII

   General Specifications:

      (1)   Construction of concrete lining shall conform to city specifications.

      (2)   Sloping walls shall have slope ratio of 1 horizontal to 1 vertical, or flatter.

      (3)   Sodded slope ratio shall be 2.5 horizontal to 1 vertical or flatter.

      (4)   Concrete liners shall be structurally designed for calculated hydraulic load to be minimum four inches - maximum six inches of 3,500 lb. concrete.

      (5)   This figure shall only be constructed in the major system.

   Figure IX

 

   General Specifications:

      (1)   Slopes back of curb shall have a ratio of 2.5 horizontal to 1 vertical, or flatter.

      (2)   Slopes shall be sodded uniformly to permit mowing.

      (3)   Concrete construction shall conform to city specifications.

      (4)   This figure shall be constructed only in the major system.

      (5)   Concrete liners shall be structurally designed for calculated hydraulic load to be minimum four inches - maximum six inches of 3,500 lb. concrete.

Figure X

   General Specifications:

      (1)   Construction of concrete lining shall conform to city specifications.

      (2)   Sloping walls shall have slope ratio of 1 horizontal to 1 vertical, or flatter.

      (3)   Sodded slope ratio shall be 2.5 horizontal to 1 vertical, or flatter.

      (4)   Concrete liners shall be structurally designed for calculated hydraulic load to be minimum four inches - maximum six inches of 3,500 lb. concrete.

      (5)   This figure shall only be constructed in the major system.

Figure XI
Runoff Coefficients for Various Land Uses
Typical Values**
Rational Method
Slope	Land Use	Sandy Soils		Clay Soils
		Min.	Max.	Min.	Max.
Flat (0—2%)	Woodlands	0.10	0.15	0.15	0.20
	*Pasture, grass and farmland	0.15	0.20	0.20	0.25
	Rooftops and pavement	0.95		0.95
	Single-family residential:
	1/2 acre lots and larger	0.30	0.35	0.35	0.45
	Smaller lots	0.35	0.45	0.40	0.50
	Multi-family residential:
	Duplexes	0.35	0.45	0.40	0.50
	Apts., townhouses and condos	0.45	0.60	0.50	0.70
	Commercial and industrial	0.50	0.95	0.50	0.95
Rolling (2—7%)	Woodlands	0.15	0.20	0.20	0.25
	*Pasture, grass and farmland	0.20	0.25	0.25	0.30
	Rooftops and pavement	0.95		0.95
	Single-family residential:
	1/2 acre lots and larger	0.35	0.50	0.40	0.55
	Smaller lots	0.40	0.55	0.45	0.60
	Multi-family residential:
	Duplexes	0.40	0.55	0.45	0.60
	Apts., townhouses and condos	0.50	0.70	0.60	0.80
	Commercial and industrial	0.50	0.95	0.60	0.95
Steep (7%+)	Woodlands	0.20	0.25	0.25	0.30
	Pasture, grass and farmland	0.25	0.35	0.30	0.40
	Rooftops and pavement	0.95		0.95
	Single-family residential:
	1/2 acre lots and larger	0.40	0.55	0.50	0.65
	Smaller lots	0.45	0.60	0.55	0.70
	Multi-family residential:
	Duplexes	0.45	0.60	0.55	0.70
	Apts., townhouses and condos	0.60	0.75	0.65	0.85
	Commercial and industrial	0.60	0.95	0.65	0.95
*Coefficients assume good ground cover and conservation treatment.
**Weighted coefficient based on percentage of impervious surfaces and green areas must be selected for each site.

 

 

Return Period (yrs.)	Multiply C by
25	1.1
50	1.2
100	1.25

 

(Prior Code, § 11-8-8) (Ord. 594, passed 8-5-1997)