Question 6. [3 Points] For a new project located in Trenton, NJ, it has been determined that the path fr the hydraulically most remote point of the drainage area to the point of concentration takes the followi path: 1. 800 ft of paved surface at a 1.5% slope 2. 140 ft of poor grass surface at a 0.9% slope 3. 60 ft of dense grass at a 6.0% slope 4. 1,600 ft of stream flow at a 1% slope. Calculate the total time of concentration using the following nomographs. 1000 -900 -800 -700 -600 -500 PAVED 400 لين ليسا ياليليليليليا 300 -200 BARE SOIL 100 90 80 70 60 50 40 82222222 -30 20 ויזיויויוייויייווווז LENGTH OF DRAINAGE STRIP IN FEET 10 POOR GRASS 0.5 1.0 CHARACTER OF GROUND AVERAGE GRASS DENSE GRASS OR WOODLAND PIVOT LINE PERCENT SLOPE OF GROUND דייוידי משר 2.0 235 3.0 000 5.0 10 120 35 30 25 20 S T T ° 6 0 INLET CONCENTRATION TIME IN MINUTES لبيت -200 po 1000 ELEVATION IN FEET OF CRITICAL POINT ON DRAINAGE AREA ABOVE POINT OF CONCENTRATION (H) 10 וחוויוידיוידי -5000 -4000 -3000 -2000 w 54 ייד 10- 20 20- LENGTH OF CHANNEL FROM CRITICAL POINT TO POINT OF CONCENTRATION (L) POINT OF CONCENTRATION POINT CRITICAL DRAINAGE 2 AREA MILES FEET 1 STREAM PROFILE 10 0.2 90 TTTTT CLONES S TITTTTTT 3 (HOURS) FLOW TIME (MINUTES)

(b) A catchment consists of an asphalt pavement that drains into a rectangular concrete channel. The asphalt surface has an average slope of 0.6%, and the distance from the catchment boundary to the drain is 50 m. The drainage channel is 30 m long, 25 cm wide, 20 cm deep, and has a slope of 0.8%. For an effective rainfall rate of 60 mm/h, the flow rate in the channel is estimated to be 0.025 m³/s. Estimate the time of concentration, te of the catchment. Hint: Use the Manning's in the kinematic wave equation form.

Solve the problem using the NRCS method for a watershed located right outside New York City, New York for a 50 year storm event. Assume the soil hydrologic group B (65%), C (25%) and D (10%). Given Am-1.29 sm. Impervious = 6.6 acres, Woods =819 acres. Overland flow: L=100 ft, s=4%, fair; Shallow Concentrated Flow: unpaved L= 2300 ft, s=2.7%, stream flow L=9000 ft, s= 3.4% The Time of Concentration is 20¹ 12¹ n = 0.035

The figure is a plan view of a confined aquifer showing two contaminated zones, 1 and 2. The aquifer has a saturated thickness of 80 ft, hydraulic conductivity of 42 ft/d, and the regional hydraulic gradient is 0.0075 from right to left as shown. A pumping well with a flow rate of 170 gpm is planned to run continuously at the location shown, and form a stable (equilibrium) capture zone. You may assume that the 2500 ft distance from the well to zone 1 is long enough that the capture zone has reached its maximum width. 2 200 ft Determine: pumping well 2500 ft 700 ft regional flow direction 1. If contamination from zone 1 find its way to the pumping well? Provide support for your answer with a capture zone analysis or contaminant simulation model. 2. If contamination from zone 2 find its way to the pumping well? Provide support for your answer with a capture zone analysis or contaminant simulation model.

A culvert is designed to pass a 50-year storm runoff, and it is designed for a 40 year life. What is the hydrologic risk of failure during the 40-year project life? A.2% B.55% C.64% D.82%

A 300 acre watershed just south of Chicago is currently undeveloped (woods). The soils are primarily clay, the hydraulic length of the watershed is 6560 ft, and the average lank slope is 1%. Determine the SCS synthetic UH before development and finish the table below. Solution: from Table 11.7; 1. For clay soil with woods cover, CN= 2. The soil moisture deficit S = in; 3. For a watershed with hydraulic length, time of concentration Te= hr min; 4. Time to peak Tp= min: 5. Peak discharge Op= cfsjin; 6. Storm duration is AD= hr= min; 7. The -min UH is displayed below using Table 11.11; Flow Time Time Ratios Flow Ratios (min) (cfs) (t/tp) (9/ap) 21 13 0.1 0.2 40 42 0.31 0.4 0.66 0.6 0,93 0.8 125 121 0.93 1.2 102 146 1.4 0.78 167 73 0.56 1.6 51 188 0.39 1.8

You are designing a drainage system for a residential site in Atlanta using a 10-year return period. The site has an area of 1 ha, a flow length of 100 m, an average slop of 1%, a Manning's number of 0.25 and Type B soil. Drainage regulations require that the kinematic wave equation be used to calculate the time of concentration. You are allowed to use either the rational method or TR-55 to calculate the peak runoff rate. It is suggested you used a runoff coefficient of 0.4, which is typical for residential sites. What curve number would be required for both the rational method and the TR-55 method to provide the same peak runoff rate?