§152.36 LAND USE.

   The rainfall loss characteristics of future condition developed land within the town and the contributing watersheds have been prepared as a part of the PDMP. The results are summarized in Tables 3.3 and 3.4. This information is to be used for all existing and proposed condition unit hydrograph models prepared for studies within the town. The engineer may use more detailed information specific to a site with written approval of the Public Works Engineer. Land-use rainfall loss characteristics for developed land for use with the Rational Method ("C" coefficients) are to be derived from Table 3.5.

(Res. 1637, passed 2-28-02)

   Table 3.3: Rainfall Loss Characteristics for Developed Land

Land-Use Class (1)	Developed
	RTIMP % (2)	Veg. Cover % (3)	IA In (4)
VLDR	20	50	0.20
LDR	25	45	0.20
MDR	45	25	0.20
MFR	65	20	0.20
C	90	5	0.05
GC	0	98	0.20
GC/N	2	85	0.20
P	100	0	0.05
RW	75	12	0.08
N	---	---	---
NC	---	---	---
L	100	0	0.00
LDR1	51	29	0.16
LDR3	58	25	0.13
LDR5	45	33	0.15
S	45	52	0.13
RES	45	33	0.15
REDI	55	21	0.18
REDH	57	26	0.16
REDF	60	28	0.14

 

(Res. 1637, passed 2-28-02)

   Table 3.4: Descriptions of Land-Use Classifications

Land-Use Class (1)	Description (2)
VLDR	Very Low Density Residential
LDR	Light Density Residential
MDR	Medium Density Residential
MFR	Multi-Family Residential
C	Commercial
GC	Golf Course/Park
GC/N	Golf Course - Not Designed
P	Paving
RW	Street Right-of-Way
N	Natural (see soils parameters)
NC	Non-Contributing
L	Lake; contributing drainage area
LDR1	Low Density PAD #1
LDR3	Low Density PAD #3
LDR5	Low Density PAD #5, #6, #7
S	School/Resort
RES	Reservation
REDI	Redevelopment Area in Sub-basin 120I
REDH	Redevelopment Area in Sub-basin 121H
REDF	Redevelopment Area in Sub-basin 121F

 

(Res. 1637, passed 2-28-02)

   Table 3.5: Developed Condition "C" Coefficients for Use with the Rational Method

Land Uses	Return Period
	2-10 Year	25 Year	50 Year	100 Year
Streets and Roads
Paved Roads	0.75 - 0.85	0.83 - 0.94	0.90 - 0.95	0.94 - 0.95
Gravel Road- ways and Shoulders	0.60 - 0.70	0.66 - 0.77	0.72 - 0.84	0.75 - 0.88
Industrial Areas
Heavy	0.70 - 0.80	0.77 - 0.88	0.84 - 0.95	0.88 - 0.95
Light	0.60 - 0.70	0.66 - 0.77	0.72 - 0.84	0.75 - 0.88
Business Areas
Commercial - Downtown	0.75 - 0.85	0.83 - 0.94	0.90 - 0.95	0.95
Commercial - Neighborhood	0.55 - 0.65	0.61 - 0.72	0.66 - 0.78	0.69 - 0.81
Residential Areas
Lawns - Flat	0.10 - 0.25	0.11 - 0.28	0.12 - 0.30	0.13 - 0.31
Lawns - Steep	0.25 - 0.40	0.28 - 0.44	0.30 - 0.48	0.31 - 0.50
Very Low Density Residential	0.30 - 0.40	0.33 - 0.44	0.36 - 0.48	0.38 - 0.50
Low Density Residential	0.45 - 0.55	0.50 - 0.61	0.54 - 0.66	0.56 - 0.69
Medium Density Residential	0.50 - 0.60	0.55 - 0.66	0.60 - 0.72	0.63 - 0.75
Multi-Family Residential	0.60 - 0.70	0.66 - 0.77	0.72 - 0.84	0.75 - 0.88
Parks/Cemeteries	0.10 - 0.25	0.11 - 0.28	0.12 - 0.30	0.13 - 0.31
Playgrounds	0.40 - 0.50	0.44 - 0.55	0.48 - 0.60	0.50 - 0.63

 

Note: Values of C for the 25-, 50- and 100-year frequencies were derived using frequency adjustment factors of 1.10, 1.20, and 1.25, respectively, with an upper limit of 0.95 for C for the 2- through 10-year values.

(Res. 1637, passed 2-28-02)