Land Subdivision
Classification | Minimum Distance Between Intersections (feet) |
|---|---|
Arterials, county collectors | 350 |
Township collectors, county-locals | 250 |
Loop streets, culs-de-sac | 200 |
Classification | Radius (feet) |
|---|---|
Arterials, county collectors | 40 |
Township collectors, county-locals | 30 |
Loops, culs-de-sac | 20 |
Classification | Distance (feet) |
|---|---|
Arterials | 400 |
County major collectors | 300 |
County minor collectors | 250 |
Township collectors, county-local | 200 |
Loop streets | 150 |
Culs-de-sac | 110 |
Type of Street | Number | Lanes | Shoulder | ||
|---|---|---|---|---|---|
Width (feet) | Width (feet) | Type (1) | (feet) | ||
County major collector | 2 | 12 | 6 | 1 | 86 |
County minor collector | 2 | 12 | 6 | 2 | 66 |
County-local | 2 | 11 | 6 | 2 | 50 |
Township collector (2) | 2 | 11 | 6 | 1 | 50 |
Loop | 2 | 11 | 5 | 1 | 50 |
Cul-de-sac | 2 | 11 | 3 | 1 | 50 |
(1) | Shoulder types: | 1 - Paved |
2 - Application, oil and stone and gravel | ||
(2) | In areas proposed for less intense development (minimum lot sizes over 1 acre), the minimum shoulder shall be compacted gravel with oil. | |
Q=AIR |
Where: | ||
Q | = | Volume of runoff in cubic feet per second. |
A | = | The contributory drainage area, in acres, both within and outside the boundary of the subdivision. |
R | = | Rainfall intensity. A minimum intensity of 2.75 shall be used. |
I | = | Coefficient of runoff applicable to the drainage area. It shall consider the soil character, slope of area and degree of ultimate development as determined by current zoning. In general, the values of the runoff coefficient will fall within the following range. For composite areas of various classifications, the coefficient for the predominate area shall be used for all calculations. |
Classification | Coefficient |
|---|---|
Parklands, golf courses, etc. | 0.15 to 0.30 |
Densities below 2 DU/acre | 0.30 to 0.50 |
Densities of 2 DU/acre and above | 0.50 to 0.70 |
Commercial | 0.70 to 0.90 |
V | = | 1.486R2/3 | S1/2 |
n |
Where: | ||
R | = | Hydraulic radius of conduit, or area of stream divided by wetter perimeter. |
S | = | Slope of hydraulic grade line, or for open channels or ditches, the slope of the water surface. |
n | = | the coefficient of friction. |
Permissible Design Velocities Open Channel Ditches | |
|---|---|
Material | Velocity (feet per second) |
Fine sand to loam | 2.5 to 3.5 |
Clay to hardpan | 3.75 to 6.0 |
Concrete-lined | 15 |
Pipe | * |
* | Minimum design velocity at flowing full condition shall be three feet per second. Pipes shall be considered "flowing full" at maximum capacity. |
Developer's Prorated Share | = | Development gpd |
Total Enlargement or Improvement Cost | Total Tributary gpd |
Developer's Prorated Share | = | Development Tributary gpd |
Total Project Cost | Total Tributary gpd to New System |
Developer's Prorated Share | = | Additional Peak-Hour Traffic Generated by the Development |
Total Cost of Roadway Improvement and/or Extension | Future Total Peak-Hour Traffic |
Developer's Prorated Share | = | Development cfs |
Total Enlargement or Improvement Cost of Drainage Facilities | Total Tributary cfs |
Land Subdivision
Classification | Minimum Distance Between Intersections (feet) |
|---|---|
Arterials, county collectors | 350 |
Township collectors, county-locals | 250 |
Loop streets, culs-de-sac | 200 |
Classification | Radius (feet) |
|---|---|
Arterials, county collectors | 40 |
Township collectors, county-locals | 30 |
Loops, culs-de-sac | 20 |
Classification | Distance (feet) |
|---|---|
Arterials | 400 |
County major collectors | 300 |
County minor collectors | 250 |
Township collectors, county-local | 200 |
Loop streets | 150 |
Culs-de-sac | 110 |
Type of Street | Number | Lanes | Shoulder | ||
|---|---|---|---|---|---|
Width (feet) | Width (feet) | Type (1) | (feet) | ||
County major collector | 2 | 12 | 6 | 1 | 86 |
County minor collector | 2 | 12 | 6 | 2 | 66 |
County-local | 2 | 11 | 6 | 2 | 50 |
Township collector (2) | 2 | 11 | 6 | 1 | 50 |
Loop | 2 | 11 | 5 | 1 | 50 |
Cul-de-sac | 2 | 11 | 3 | 1 | 50 |
(1) | Shoulder types: | 1 - Paved |
2 - Application, oil and stone and gravel | ||
(2) | In areas proposed for less intense development (minimum lot sizes over 1 acre), the minimum shoulder shall be compacted gravel with oil. | |
Q=AIR |
Where: | ||
Q | = | Volume of runoff in cubic feet per second. |
A | = | The contributory drainage area, in acres, both within and outside the boundary of the subdivision. |
R | = | Rainfall intensity. A minimum intensity of 2.75 shall be used. |
I | = | Coefficient of runoff applicable to the drainage area. It shall consider the soil character, slope of area and degree of ultimate development as determined by current zoning. In general, the values of the runoff coefficient will fall within the following range. For composite areas of various classifications, the coefficient for the predominate area shall be used for all calculations. |
Classification | Coefficient |
|---|---|
Parklands, golf courses, etc. | 0.15 to 0.30 |
Densities below 2 DU/acre | 0.30 to 0.50 |
Densities of 2 DU/acre and above | 0.50 to 0.70 |
Commercial | 0.70 to 0.90 |
V | = | 1.486R2/3 | S1/2 |
n |
Where: | ||
R | = | Hydraulic radius of conduit, or area of stream divided by wetter perimeter. |
S | = | Slope of hydraulic grade line, or for open channels or ditches, the slope of the water surface. |
n | = | the coefficient of friction. |
Permissible Design Velocities Open Channel Ditches | |
|---|---|
Material | Velocity (feet per second) |
Fine sand to loam | 2.5 to 3.5 |
Clay to hardpan | 3.75 to 6.0 |
Concrete-lined | 15 |
Pipe | * |
* | Minimum design velocity at flowing full condition shall be three feet per second. Pipes shall be considered "flowing full" at maximum capacity. |
Developer's Prorated Share | = | Development gpd |
Total Enlargement or Improvement Cost | Total Tributary gpd |
Developer's Prorated Share | = | Development Tributary gpd |
Total Project Cost | Total Tributary gpd to New System |
Developer's Prorated Share | = | Additional Peak-Hour Traffic Generated by the Development |
Total Cost of Roadway Improvement and/or Extension | Future Total Peak-Hour Traffic |
Developer's Prorated Share | = | Development cfs |
Total Enlargement or Improvement Cost of Drainage Facilities | Total Tributary cfs |