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98 - Design Report - Gallatin Center PUD - Stormwater
STORMWATER MASTER PLAN for THE GALLATIN CENTER P.U.D. FINAL PLAN REVISED NOVEMBER 1998 SC ENTIST SMORRIS0NS S CPL-NNERMAIERL IN . SINCE 1945 An Ernployae-Oumsd Prepared by: H:\2393\006\WPD\STORM\PUD\STORMRPT.WPD G�'C i�/ NT j � � STORMWATER MASTER PLAN THE GALLATIN CENTER P.U.D. INDEX I. An Introduction to the Existing Drainage Systems II. The Proposed Drainage Plan III. Exhibits APPENDIX August 4, 1998 Letter from MDT Runoff Calculations i z .existing Drainage Bashi iI CANAL 1 ' } I --- -- - - I �- �_~�" - ---- -•; Pu� --_ I for _=Tie Gallatin Center P U.D.__- 44 Qi -- — l —Bast Catron Basin I — , West Catron Basin ; i ( 'j N; • .', �� �:r- _ -�- -;. ( / t` 942 A cres — — — 386 Acres -- � -- . I' •a --ti= _"-- ! i ------------- zr Carroll Basin - �' ---- L. • = .• _, !: ' �:� -may -,-.~ — i 415Acres 1 I �'�• G .. . .r-- -.�.../ �' ——_ SOUTH J. 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'��- %w _ ---t. � :�%�%1 ���-='r-=-J�'r� .Jl,,a� �,i� _ -./t- f i•• h' .'�-• .,.- �L ,c�. ,':..�..�. -- � , i (`r�. -\� . _- I\ .\,\ ��� � � %. iC� �� •--"���'-� �F� -_-"('";Z"���"_r^_t!'_-�yZ.._-_:,�"���-:vr' (�•`r•��l �I.•` .�;fr •,.` 1.4���` '• �J .�: J� •:\\ `� J� c 1`'- � r ( \ ^\ � '-- \`�./"✓'." -�-•`._r--'�I /� - � �. ^y-`i���i1,�1 Y.�/'Y j / ;r3� �� '-�:_.i a ,' •/ r ' \`� /�/,ry•,/ j, -,i` ©� Jltj:^•� \� , -- �` / � .J \� '�-��\� - •� `�, � Czl .l'.irj pti�.i% '`✓b� •�%. /rG�!\_'i � ; / —�� �'.�r � , -��-���' `'� 1 �•1 �•l /� `Y�ii� 1 -� \' . ' S• i;�i �•...r--' _• - ./ �-� . .^mil :. /� .�'r ---_-� � x I' q_ I. An Introduction to the Existing Drainage System The Gallatin Center P.U.D. is located in the east half of Section 35, Township 1 south, Range 5 east. More specifically, The Gallatin Center is located north of Baxter Lane, south of Valley Center Road and adjacent to the west right-of-way of N. 19"Avenue. The existing drainage system for the land of interest consists of two stream-ditches that flow northerly into the East Gallatin River. They are identified as the East Catron stream-ditch and the West Catron stream-ditch. The Carroll Basin The East Catron has a tributary known as the Carroll stream-ditch with its drainage basin located immediately east of the East Catron basin. Please see the Existing Drainage Basin Map for respective locations. Currently,the Carroll stream-ditch is not mapped by the National Flood Insurance Program for the 100-year flood plain. Moreover, the drainage basin is less than twenty-five square miles and therefore, does not require flood hazard evaluation under chapter 16.20 of the Bozeman Area Subdivision Regulations. The Carroll stream-ditch has its point of origination three miles south of Durston Road. Its drainage basin is approximately 415 acres in size and is composed of equal areas of agricultural, residential, and commercial land use. The are numerous manmade features which interrupt flood flows within the natural basin. They include roadways, irrigation ditches, leveled fields, culvert structures, and irrigation diversion structures. Therefore, it is difficult to calculate a realistic runoff that reaches the site. To account for the influences of existing culvert structures and ponding areas upstream of culverts, a longer time of concentration was used to slightly attenuate the peak flows. It is noted that this section of town is fairly mature with few, if any retention/detention ponds in place. The Carroll stream- ditch proceeds through town by means of underground concrete piping and open channel stream- ditches. The rational method and the City of Bozeman Storm Water Master Plan were used to calculate the peak runoff for a each given storm event. The summary of runoff peaks are in Table 1. Table 1. Carroll stream-ditch Basin Post-Development Flows (CFS) Outfall Q 10 Q25 Q 100 Durston Road 70 86 109 W. Oak Street 78 96 123 (The Carroll stream-ditch joins the East Catron stream-ditch 950'north of W.Oak Street.) A closer look at the path of the Carroll stream-ditch reveals certain underground structures may be in question. At W. College a 24" CMP conveys about half of the 25-year event with the remaining runoff either backing up into a vacant field or flooding W. College. From this point the runoff proceeds north by means of an open channel for 1100 feet where a 24" RCP intercepts the flow. Storm inlets in this section of town feed additional runoff to the storm The Gallatin Center P.U.D. 1 main. The main outfalls from a 31"x50" CMP into Kirk Park where the runoff flows to the north end of the park by means of an open channel. A 36" RCP at the north end of Kirk park appears to be adequate to convey the 25-year storm event further north to another open channel. This stream-ditch along the rear lotlines of West Park Manor#3 also appears to have the capacity for the 25-year event with minimal flooding. However, where this stream-ditch meets Durston Road a bottle-neck occurs. The 25-year storm event of 86 cfs has to fit into an existing 24" RCP and proceed east along Durston Road. The capacity of the existing 24" RCP is approximately 25-30 cfs. Therefore, what can not fit into the 24" pipe must be conveyed to the east as street now down Durston Road or it may cross Durston Road and proceed to the east in a swale on the north side of the road. Independent of the path, the outfall is near the twin 24" CMP crossing in Durston Road near N. 2011 Avenue. It is apparent that the storm main in Durston Road is undersized. For details regarding this area see figure 1. DURSTON Roan ;' N xo — II. SIDS O, � 24— — w x - _ __ —i ►_ 2 --- { Id IS ._ I { 2u 14 ev J _ • —'— I sio sxo Figure 1 The Carroll stream-ditch continues to flow north past Durston Road by means of open channel flow. The next obstacle encountered is an existing 36" CMP under Windsor Street. It is surprising to see a corrugated metal pipe under a such a recently constructed road. This culvert is undersized since a headwater depth of 9.6' under outlet control would be required to push the 25- year storm event through. The difference in elevation between the existing stream-ditch bottom and the top of the road is 4.53'. Suggested remedies may include the addition of another 36" CMP or the replacement of the existing CMP with a new 31"x51" ARCP that will pass 93% of the 25-year event and still provide 1.5 feet of cover over the top of pipe given the existing road elevation. Currently, storm events that can not pass through the existing 36" CMP must overtop the road and flow back into the stream-ditch. Site grading of all lots adjacent to this crossing is imperative to prevent the inundation of building structures. As the Carroll stream-ditch continues north it must pass through existing twin 24" RCPs under Maplewood Dr. The capacity of the twin 24" RCPs is approximately 52 cfs under inlet control with a headwater depth of 3.6 The Gallatin Center P.U.D. 2 feet which is just below the crown of toe road. Unfortunately,the 25-year event produces an approximate runoff of 90 cfs at this location. It is apparent that the twin 24" culverts are not adequately sized and may require replacement with a new 31"x51" ARCP. The next obstacle the Carroll stream-ditch encounters is West Oak Street. Here an existing 31"x51" ARCP conveys flow under West Oak Street. The capacity of this culvert is approximately 95 cfs under inlet control with a headwater depth of 5.0 feet. The rational method produced a 25-year storm event rate of 96 cfs. Therefore, calculations show that this culvert will barely pass the 25-year peak without overtopping the road. However, considerable ponding will have to occur to achieve this flow rate. After passing W. Oak Street, the Carroll stream-ditch travels its last 950 feet before joining with the East Catron stream-ditch. The East Catron Basin Currently, the East Catron stream-ditch is not mapped by the National Flood Insurance Program for the 100-year flood plain. Moreover,the area of the combined drainage basins is less than twenty-five square miles and therefore, does not require flood hazard evaluation under chapter 16.20 of the Bozeman Area Subdivision Regulations. The East Catron stream-ditch has its point of origination four miles south of Durston Road. Its drainage basin is approximately 942 acres in size and is composed of equal areas of agricultural, residential, and commercial land use. Once again the numerous manmade features complicates the runoff calculations but not to the degree that effected the Carroll stream-ditch. The East Catron stream-ditch has fewer obstructions and is conveyed by way of open channel through its entire travel route with the exception of road culverts. Once again the rational method was used to calculate runoff rates with the summary of results found in the Table 2. Table 2. East Catron stream-ditch basin Post-Development Flows (CFS) Outfall Q 10 Q25 Q 100 Durston Road 127 158 197 W. Oak Street 161 199 250 Tschache Lane 195 241 304 Baxter Lane 198 245 309 Seitz Street 199 246 310 Deadman's Gulch Dr. 205 250 314 Burke Street 212 260 328 Catron Street 220 270 333 A closer look at the path of the East Catron stream-ditch reveals that certain underground structures may also be in question. There is an existing 40"x65" CMP under Durston Road with a capacity of 90 cfs operating under outlet control. However,the 25-year storm event produces a peak runoff rate of 158 cfs. Therefore, the culvert appears to be undersized with 60-70 cfs overtopping Durston Road and rejoining the East Catron stream-ditch on the other side. At some The Gallatin Center P.U.D. 3 time in the future it may be necessary to replace the existing culvert with a new 40"x65" ARCP. The East Catron then crosses under West Oak Street by means of two 36"X58" ARCP These culverts are adequately sized to convey 199 cfs or the 25-year storm event with a headwater of 4.2 feet measured from the pipe invert. The East Catron stream-ditch proceeds north and eventually meets the Carroll stream-ditch. The joining of these two stream-ditches yields a single stream-ditch that takes the name of the larger stream-ditch, the East Catron. The next obstacle encountered by the East Catron stream-ditch is Tschache Lane of the Stoneridge Major Subdivision. At this location the rational method estimated the 25-year storm event to produce a runoff rate of 241 cfs. In light of the cost of reinforced concrete arch pipe,two alternatives may be considered. The first alternative is to use a 54"x88" ARCP with a headwater depth of 5.4 feet and a capacity of 240 cfs operating under the inlet control condition. A second alternative may be to use a Tx4' box culvert with a headwater depth of 5.4 feet and a capacity of 240 cfs operating under inlet control. Since the difference in elevation between the culvert invert and the centerline elevation of Tschache Lane is six feet, water will not overtop the road using either alternative. It is noted that as the size of these concrete culverts become extraordinarily large so does the cost. It may be advantageous to look at a third alternative using corrugated metal pipe as a cost effective solution. The Stoneridge Subdivision offers one last obstacle to the East Catron stream-ditch. Baxter Lane has an existing 44"x72" ACMP with a capacity of 159 cfs operating in the inlet control condition. Please see the appendix for culvert nomographs. The rational method estimated that the 25-year storm event will produce a runoff rate of 245 cfs. Since this culvert can not pass the entire flow, a pond forms to the south of Baxter Lane and extends easterly to the barrow ditch of N. 191h Avenue. At this location there is an existing 36"x58" ARCP that crosses N. 19`h Avenue and some of this backup flow passes through this culvert to the east side of N. 19`h Avenue where a second pond is formed. These make-shift pond areas may be filled during construction of the Stoneridge Subdivision which may amplify flooding issues for properties near the intersection of the stream-ditch and Baxter Lane. Grading in this area can be implemented such that the overflow runoff at Baxter Lane can safely pass over the road surface and back into the East Catron stream-ditch without inundating new buildings. An additional solution may be to replace the existing undersized culvert at Baxter Lane with one 54"x88" or two 36"x58" ARCP possessing adequate capacity. This would allow the 25-year event to pass through the culvert. However, a larger storm event would still cause possible flooding if special site grading is not performed. Therefore, site grading is probably the most cost effective way to remedy the drainage problem at Baxter Lane. It is noted that the property on the northeast corner of Baxter Lane and N 19`h Avenue (Anderson Precast) has a building pad elevation that is lower than the adjacent roads. Currently, excessive runoff flows over Baxter Lane and into the east right-of-way ditch of N. 19"' Avenue. As the intersection of Baxter Lane and N 1911 Avenue is improved the overflow crossing point in Baxter Lane may be shifted further east which would direct the flow into the entrance of the Anderson Precast property and present potential flooding. Further attention should be given to this location to minimize the chance of flooding this business. The East Catron then proceeds north and crosses onto the property of the Gallatin Center where the proposed drainage plan shall begin. As a result of the Preliminary Plat and storm water report submittal, the Montana Department of Transportation issued an August 4, 1998 letter concerning this plat. We shall The Gallatin Center P.U.D. 4 respond to this letter on a line by line basis with a copy of the letter found in the appendix. Lines 4-7 of the attached letter: "The proposed culverts for The Gallatin Center Major Drainage System will allow a post development 25 year flood of 320 cfs through Catron Street.... " As per page 3 of the Grading & Drainage report for the Gallatin Center P.U.D. the runoff is 270 cfs. Lines 7-10 of the attached letter: "We are concerned that proposed grading activities for these and other developments, as well as increasing culvert capacity at Baxter Lane (or eliminating a detention process) will create potential flooding at East Valley Center. " It is our concern as well. However the culverts at the interstate near East Valley Central Drive should convey runoff generated by the 25-yr post development event. Prior to the creation of these and other developments within this basin, flooding of the East Valley Center culverts has already occurred. This suggests a pre-existing condition. A possible solution may include increasing the capacity of these culverts funded by a state or federal highway project or through City of Bozeman and Gallatin County impact fees. Lines 10-11 of the attached letter: "The proposed detention ponds for the storm drain(age) will work for floods smaller than the 25 year events, but will not serve to attenuate the larger events. " The City of Bozeman requires for commercial development to size pond facilities using the 10-yr storm event(page I11-5 of the Storm Water Master Plan for the City of Bozeman). Therefore, only storm events equal to or less than 10 years will be attenuated to pre-developed conditions. In addition, site grading should be implemented to prevent structure inundation for storm events greater than the 25-yr event in the East Valley Center location. Lines 11-12 of the attached letter: "Replacing the existing 245 cfs culvert at Baxter Lane should be removed from consideration. " Our calculations estimate the capacity of the existing 44"X72" corrugated metal arched pipe at Baxter Lane on the East Catron to be 159 cfs in the inlet control condition. This figure is considerably less than the 245efs that the MDT has indicated. If the capacity is 245 cfs, then the 25-yr post developed event is conveyed. Replacement is not suggested for the Gallatin Center Project but is noted for your information and further consideration. Lines 12-13 of the attached letter: "Storm water run-off will not be permitted onto roads under State jurisdiction. " It is unrealistic to specify that runoff will not be permitted onto roads without specifying a probability or recurrence interval such as 25, 50 , 100 or 200 years. It is our opinion that the existing culvert under Baxter Lane is undersized by approximately 90 cfs. The Montana Department of Transportation does not agree with our calculation. However, since the Stoneridge Major Subdivision (located just south of Baxter Lane and between the East Catron Stream and N.19th Avenue)has preliminarily platted a 80,000 cft detention pond in the area of interest, a crucial natural detention feature may be preserved. In fact it may be enhanced and increased in size from its natural dimensions. This pond can provide some additional storage behind the existing culvert at Baxter Lane that will be required on a more frequent basis than the 25-yr recurrence interval. It is imperative that site grading and first floor elevations be specified such that larger storm events will pass over roads and back into natural stream channels without inundating any building structures when unable to pass through culverts. The Gallatin Center P.U.D. 5 The West Catron Basin Currently, the West Catron stream-ditch is not mapped by the National Flood Insurance Program for the 100-year flood plain. Moreover, the area of the combined drainage basins is less than twenty-five square miles and therefore, does not require flood hazard evaluation under chapter 16.20 of the Bozeman Area Subdivision Regulations. The West Catron stream-ditch has its point of origination just over one mile south of Durston Road. Its drainage basin is approximately 386 acres in size and is composed of agricultural, residential, and commercial land use. The West Catron stream-ditch has few obstructions and is conveyed by way of an open channel through its entire travel route with the exception of road culverts. Once again the rational method was used to estimate runoff rates with the summary of results found in the Table 3. Table 3. West Catron stream-ditch basin Post-Development Flows (CFS) Outfall O10 025 Q100 Durston Road 27 32 41 Baxter Lane 31 38 47 Seitz Street 37 45 56 Minteer Street 44 55 67 Deadman's Gulch Dr. 43 53 67 Catron Street 41 50 60 A closer look at the path of the West Catron indicates that one of the existing culverts found within the basin may be inadequately sized. At the intersection of the West Catron stream- ditch and Durston Rd. an 18" CMP has a capacity of 6 cfs with the 25-year storm event having a estimated runoff of 32 cfs. Ponding and overtopping of the roadway may accompany the 25-year storm event at that location. Further down stream at Baxter Lane, an existing 43"X27" ACMP is encountered. The 25-year storm event produces a runoff or 30 cfs at this outfall with the existing 43"X27" ACMP capacity of 40 cfs. The West Catron then crosses on to the property of the Gallatin Center where the proposed drainage plan begins. The Gallatin Center P.U.D. 6 U. Proposed Drainage Plan The Gallatin Center P.U.D. Drainage Plan consist of two drainage systems. The primary system is designed to provide public convenience and to accommodate moderate, relatively frequent flows. The major drainage system has a much greater capacity to convey more water and operates when the rate or volume of runoff exceeds the capacity of the minor system. The return period for the minor drainage system shall be 25-years. The major drainage system shall convey I00-year events without inundating building structures. Development tends to increase downstream peak flow by increasing runoff volumes and by decreasing the time it takes the runoff to travel downstream. As part of the minor drainage system, retention and detention ponds designed for the I0-year return period shall be implemented to reduce the downstream peak runoff to levels that existed before the subdivision was created. The ponds will also provide settlement time for sediment and other storm water pollutant loads to drop out. Design of the Gallatin Center P.U.D. Grading and Drainage Plan will take advantage of the natural features that will contribute to the management of storm water. Engineering techniques shall be used to preserve and enhance the natural features and processes of the site. This in turn will maximize post-development economic and environmental benefits,particularly in combination with open space and recreational uses. Our design shall improve the effectiveness of the natural systems, rather than negate, replace or ignore them. The Major Drainage System: The backbone of the major drainage system is comprised of the West and East Catron stream-ditches. These waterways shall have the channel capacity to convey the runoff generated by return periods equal to or less than 100-years without inundating any building structures. However, all culverts placed within these waterways shall be designed for the 25-year return period. Specifying culverts for an event greater than the 25-year return period would result in excessive culvert costs with a minimal reduction in the potential for adverse consequences. Moreover, there is always the possibility that ice or debris could plug the culverts. It would be more cost effective to protect building structures by investing in site grading and by specifying adequately elevated building pads adjacent to these waterways. Site grading shall be completed so that storm events between the 25-year and 100-year return periods will pass over roadways or through emergency overflow areas without inundating any building structures or causing significant erosion. This is imperative due to the high property values associated with commercial development. Please see Exhibit"C" for culvert locations and channel contours. A summary of results are as follows: The Gallatin Center P.U.D. 7 Post Q100 Min.Bottom Width Side Slopes Depth Top Swales and Natural Channels (Cfs) (Ft) (H:V) (Ft) (Ft) East Catron stream-ditch @ Baxter Lane 381* 14.6 3:1 2.5 29.6 @ Deadman's Gulch Dr. 418* 16.4 3:1 2.5 31.4 @ Catron Street 428* 16.7 3:1 2.5 31.7 West Catron stream-ditch @ Baxter Lane 89* 2.8 3:1 2.0 14.8 a Deadman's Gulch Dr. 100* 3.6 3:1 2.0 15.6 @ Catron Street 89* 2.8 3:1 2.0 14.8 Note:All waterways have a bedslope of 1.0%and are assumed to be grass-lined with some brush(n=.032) * 100-year storm event calculated assuming entire drainage basin is developed,C=0.6. It is noted that these widths are minimum values as calculated using the Manning equation. Post Q25 Description Slope Head Act.Cap Culverts (Cfs) (fUft) (Ft) (Cfs) East Catron stream-ditch a Baxter Lane 245 I-New 54"X88"ARCP .011 5.4 245 or 245 2-New 36"X58"ARCP .011 5.1 245 or 245 1-Existing 44"X72"ACMP .011 6.5 159 a Seitz Street 246 I-New 54"X88"ARCP .011 5.5 246 or 246 2-New 36"X58"ARCP .011 5.2 246 a Deadman's Gulch 250 1-New 54°X88"ARCP .011 5.6 250 or 250 2-New 36"X58"ARCP .011 5.2 250 @ Burke Street 260 1-New 54"X88"ARCP .011 5.7 260 or 260 3-New 31"X51"ARCP .011 4.7 260 @ Catron Street 270 1-Existing,undersized .011 5.0 140 40"X65"ARCP West Catron stream-ditch @ Baxter Lane 38 Existing 43"X27"RCMP .011 2.8 38 a Seitz Street 45 New 27"X44"ARCP .011 3.0 45 @ Minteer Street 55 New 27"X44"ARCP .011 3.6 55 @ Deadman's Gulch 44 53 New 27"X44"ARCP .011 3.5 53 @ Catron Street 50 Existing,oversized .011 3.9 115 40"X65"ARCP Note:All new culverts are sized to convey the peak runoff from the 25-year storm event. Head is measured at upstream end from invert to water surface. The option of two culverts adds 2-3%to the cost,however it lowers road elevations and associated costs. The Gallatin Center P.U.D. 8 The Minor Drainage System: The minor drainage system is comprised of streets, inlets, curb chases, swales, and detention ponds. Runoff from lands just east of the West Catron and west of the East Catron shall make its way by means of overland flow, swales, and curb chases into ponds. The shallow swales shall be designed to convey the 10-year storm event to low-visual impact detention ponds. The ponds shall be around two feet deep and shall be designed to detain the 10-year post- development runoff volume while releasing flow at a rate not exceeding the 10-year pre- development rate. If larger storm events are encountered, site grading and the emergency pond overflow structures (rip-rapped, broad crested weir) will provide a designated path for the overflow to pass into either stream-ditch without inundating any building structures or causing significant erosion to the pond or stream. The modified rational method was used to size all detention ponds. Please see Exhibit"A" for the pond locations as well as the subareas contributing to each respective pond. The ponds shall have a predominantly flat bottom. The ten year storm event was routed into each pond and through the outlet structure using a"delta time step &mass balance"method. All outlet structures are modeled to operate in the inlet control condition with the weir and orifice equations used to model the release rate with respect to pond depth. The design of the pond outlet stricture shall be simple, visually unobtrusive, and cost effective. It is proposed that small diameter high density polyethylene (H.D.P.E.) culvert pipe will accomplish these two tasks at once. H.D.P.E. pipe shall be the pond's release culvert and at the same time, provide control of the release rate. The typical cross-section of the East and West Catron stream-ditches including the trail can be seen on Exhibit"C", The Grading and Drainage Plan. Note that the stream-side trail is utilized within this typical section to increase recreational value while playing a functional role in separating the stream-ditch from untreated storm runoff. The summary of detention/retention pond design results are as follows: Detention Ponds Description Det Pond Vol. Outlet Structure Min Slope Depth Release Rate (cft) (FT/FT) (170 (cfs) Lot 1 2,900 (to be designed at the time of the Site Plan) 0.8 Lot 2 2,716 (to be designed at the time of the Site Plan) 0.7 Community Pond#2 5,250 1-8"HDPE n=.010 0.015 1.7 2.2 Community Pond#3 1,900 1-6"HDPE n=.010 0.012 1.7 1.2 Community Pond#4 18,000 1-12"HDPE n=.010 0.002 1.6 3.7 Community Pond#5 20,500 1-10"HDPE n=0.10 0.030 2.5 4.8 Lot 8 rear 1,700 1-6"HDPE n=0.10 0.018 1.9 1.3 Lot 9 rear 1,700 1-6" HDPE n=0.10 0.010 2.0 1.2 Lot 10 rear 3,900 1-6"HDPE n=0.10 0.027 2.0 1.4 Lot 13 880 (to be designed at the time of the Site Plan) 0.8 Lot 14 620 (to be designed at the time of the Site Plan) 0.6 Lot 15 620 (to be designed at the time of the Site Plan) 0.6 Lot 16 710 (to be designed at the time of the Site Plan) 0.6 Lot 17 2,056 (to be designed at the time of the Site Plan) 1.5 Lot 18 2,110 (to be designed at the time of the Site Plan) 1.6 Lot 19 2,479 (to be designed at the time of the Site Plan) 1.7 The Gallatin Center P.U.D. 9 Detention Ponds(cont'd) Description Det Pond Vol. Outlet Structure Min Slope Depth Release Rate (cft) (FT/FT) (Ft) (cfs) Lot 20 2,536 (to be designed at the time of the Site Plan) 1.7 Lot 21 1,973 (to be designed at the time of the Site Plan) 1.3 Lot 22 27,181 (to be designed at the time of the Site Plan) 4.3 Lot 23 1,803 (to be designed at the time of the Site Plan) 1.2 Lot 24 917 (to be designed at the time of the Site Plan) 0.6 Lot 25 703 (to be designed at the time of the Site Plan) 0.5 Lot 26 562 (to be designed at the time of the Site Plan) 0.5 Lot 27 4,008 (to be designed at the time of the Site Plan) 2.0 Lots 1 and 2 shall not be disturbed during the construction of Phase I except to install services from existing and proposed utilities. Due to this negligible disturbance,ponds or culverts will not be constructed at the time of Phase I. However, the storm water improvements shall be designed, shown and planned for constriction on the individual site plan of each lot. Lots 3, 4 and 5 shall not be disturbed during the constriction of Phase I except to install services from existing and proposed utilities. Therefore, the storm water improvements shall be designed, shown and planned for construction on the individual site plan of each lot. These lots can share one pond within the storm water pond easement located on lot 5. Please see Exhibit"A"for the location of Pond 42. As each lot develops,the single pond shall be increased in volume to accommodate the increased runoff. If lot 5 is the first lot to develop,then the entire pond volume shall be constructed to facilitate the complete site landscaping of lot 5. This pond will be partially located within the East Catron stream corridor and will be integrated with the stream meanders. Further refinement of this pond may occur as the site plan for lot 5 is developed. Lots 6 & 7 shall not be disturbed during the construction of Phase I except to install services from existing and proposed utilities. These lots can share one pond within the storm water pond easement located on lot 7. Please see Exhibit"A" for the location of Pond#3. As each lot develops, the single pond shall be increased in volume to accommodate the increased runoff. If lot 7 is the first lot to develop,then the entire pond volume shall be constructed to facilitate the complete site landscaping of lot 7. This pond will be partially located within the East Catron stream corridor and will be integrated with the stream meanders. Further refinement of this pond may occur as the site plan for lot 7 is developed. Lots 8, 9 & 10 - Lot frontages shall share one pond within the storm water pond easement located on lot 8. Please see Exhibit"A" for the location of Pond#4. The development of lot 8 shall be completed during the construction of Phase I and therefore the pond shall also be completely constructed and is shown on the site plan for lot 8. Roof drainage to the west shall be detained on each individual lot as each lot develops. Lots 11 & 12 shall share one pond located on lot 11. Please see Exhibit"A" for the location of Pond#5. A storm water pond easement shall be provided on the final plat. As each lot develops, the single pond shall be increased in volume to accommodate the increased runoff. If lot 11 is the first lot to develop,then the entire pond volume shall be constructed to facilitate the complete site landscaping of lot 11. This pond will be partially located within the East Catron stream corridor and will be integrated with the stream meanders. Further refinement of this pond may The Gallatin Center P.U.D. 10 occur as the site plan for lot 11 is developed. Lots 13 through 27 shall have retention/detention ponds constructed with in the boundary of each lot. The site plan for each individual lot shall show the proposed pond location and size. The volumes of a typical detention pond for each lot is shown above as an example of the required size. All lots have access through drainage easements or public corridor easements to an outfall. The Storm Water Maintenance Plan: The maintenance of the onsite storm water collection, detention and discharge release appurtenances shall be integrated as part of the duties of maintenance personnel responsible for normal grounds keeping. Duties shall include routine inspections to ensure that debris, yard waste, and seasonal ice does not impede operation of the detention ponds and discharge structures. These inspections shall occur after each major runoff event and on a continued monthly basis throughout the year. All results shall be recorded and kept on file for future verification by regulation agencies. In addition to the routine inspections, annual inspections of appurtenances shall assess and mitigate, if necessary,performance of the detention ponds, and release structures. These inspections shall address accumulation of sediment and debris in the detention ponds and release structures as well as any weather or vandalism-related damage. Detention ponds and swales shall be mowed on a regular basis during the growing season so as to remain free of vegetation that might impede their conveyance capacity. The Gallatin Center P.U.D. 11 III. EXHIBITS The Gallatin Center P.U.D. 12 8 AS,CAP - ^• - .,. .. =i _ CR ' c a scu,c } i ✓ n. , L4 18, 8LK 2 2,594 a t t � _ , LOT 9 BLIt�2 TAP,UET _ _:.: 263179 s .ft. I . :6:04 acres 8 :? $, - �n I t ..I - ., t5 ,..� �� I J '. .,:;.{ �: }./ T i n/.v A� t __ _- .. i i" E �I,fit- t' ,,.r•.: 1 j ✓ . ,. .... - !s '., f S 1 \ . , _ :gym LOT 17 Z 2 _.: —X _ - ! , .. .... -.:. .m , ..... >. �, _. .._.:;.- , ..... _. :.:.:" .: ,---:�:'�=—' -f J i 1 t I> _ _ _ _61 q - N f _ ----'"'S 1 25 1 P! a- t .0_ t.. .. ...-.^""'►- f } t t ♦ � ���"�"•�-'� t \. ti SS ,k € . _5-Una. ,.,...... ... t _.. F .. , .. ..::: ,�„ IF;� _ i5Ti M } •' •__., l-_,._,,,.,«,,, 1 .` 41ARKE0]111 rS .� , .•.' .,.. „-_• ... .>., _ ` } { 77, _ - ;' / - 1 I :_5,a .+: ,.�.;r Fn s �._k F� .rxi2•Fd :..... i F :i r'< \ \\ \\ 1 2 SA- 1,550-sq.f . ,,- — --- — ;.._ _ A r. lg r 3 � vu� t` , ' - I L 1$ -� s- 3,109 ft• �.. _ ,z` _ .1 q k 9 act , lk r b 1 f'xlu LO 12 LK:_ I ? c v 1 BLK 2 ?374 t_ 600 4'6 ft ._ v LOT\14 \ q T <�::._.,>A>.lt aces._` _ \ _a, ��. ,1 `i. , 4::, m "•� ;/" , . 13.7 .acres .. ,_ ;-, ., . ._.'_ .. \ "�;- ". " ":a "_ _. .. � f �I� ✓<:�" lam, ��� _- . LEGEND 43, 6 sq`.ft, - Y ,• 1.00 ores - - , h •x i I \ , EXISTING CONTOURS ,_ PROPOSED CONTOURS , io - a b' PROPOSED PONDS .,.� 9 4 8 .f t - t /r r /fit f __.... .. ... ,\.. " , rN0 YkN w __:_ :. .,._.. fN0 5 B kE3AR.:„Y.�.... NOA '.57f21P w. ' _.._ .:. ,. __,., :.` ",.._..,.,, •....._. •�,-_...... --�'__=,� __ -o - -1`N ACCESS �.: '�- / //,' r /'i, .... ............._........................__...........:...,,..... ...... .... .......:... ............ q,Etrc .. ... .........,._..........r.............r..............,... .... ..........,...y................ ............... , _ Isi: w 6' TRAIL 6' TRAIL � ,.. '`EXHISIT °C° 3:1 2.0' DEEP GRASS UNED �31 3:1 2.5' DEEP 3.1 GRASS LINED MORRISON SURVEOM scvtnsrs ,�a 5' BOTTOM 15' BOTTOM Pt,"m MAIERLE�INC. �1m GRAPHIC SCALE OCAP - 120 CFS THE GA L L A TIN CENTER QCAP 450 C,FS A.�,,t.$ —ter C-3—V 0100 — 100 CFS Q100 a 360 CFS PA 9.1113 4m r.*.tAd Emma{Yt srnI.Rmc(400 SA-= ra Noal sn-178 RENSION DATE: 1 tma6 00 m DRAINAGE & GRADING DRAYIN4 BY: CUW DATE, 5/REVISICN 98 1 I'Xi7-Scale: 1 inch ffi 220 Et. TYPICAL CHANNEL SECTION TYPICAL CHANNEL SECTION 2393/008/STORM/ORANSHTI 1'`onto"'Intel FOR WEST CATRON CREEK FOR EAST CATRON CREEK CHECKED BY: JOB NO.: 2393.006.030.0310 SHEET 1 OF 2 Ill - -- F 7 , -_...,' _.......,_.....__,u_.._ ( `"'i ./ .. ...,.... - ...__... ., .... .. .,.__...»_... ...._.... _.- "' FND T BASS:CAP.v„ z •-- -.-,.. _- _--.-Z._ w. - — —_ t-„west,._. ' _ s , /7", Jr i/r� � II Ia , .i I s I .✓ 1 r � .' � 'I Ire ,� f� LOT 1'B � ✓/ i - - - I, r � i� I �� /r / '34 aGr6 "••� ..' ••� r� �� 'REl -TE STREAM 4 I < n 1 4 res 128 62 s .ft. � ;I �' I1, ✓ .96 a res ...-' ,- :I � _^� / ., f..... \.� �;,� � r r / !: r _ a es c : � LO 20',B_ ,3 � - - � 73 I 'LOT .a I; • 1 54 t v _ ::/ /� ' ,� � ,-• ., � r I• .,A '.33 acr s I i T 2 B 4 r '; ,' r, .;,< COMMON F 4. f - Of�EN SPACE 2 t 5. 1 s t. ,..., �., y � — - — 1 ,ft. 1 4 res / q tD { — „ — LvT '9v'oin 4 , 3�D acres I �` a COMMON 1 / } 34961 s u OPEN.-SPACE 1 pNi t- - ' _ �- 214,832 sq.ft;- —s v I _ _ , r 4.93 acres - y..1 4,277 ft.', X � T' - 2 ac es 91 ft , B' 4 WEST M 3 �tOT 1 B. i 1 • t , R. 61 res i 7 4 sq _ _ 4 2 5 ,I _!,._ 0. 6 a C k� �-- r _ ,� � I�I I „ i ' g 1 ` 11 t , zs r , � y I; .' ;� PND ipc / .✓ �,A,C .... ,..r .., �� �• �) '..OT 16 IILK / r :( 1,550`sq.f �! — i :Y r , OT "BLKCD 1, 06,5 2 sq. - 't 15 t �v .I ►+ v vv �� F 3,09 2.ft. Qk 9 acr 10m �,l it , •i ! {E t� f \ , v _ v -2 4193 r. . r t I BLK '2 43, 6 sq:ft '> 00 GND CA TON YPC ., , �.., _ / crest. I LEGEND <I LOT 22i B 4 4,, I 1 r ,. i 2 5, 4 -sq. L t, " 11 3 OGfE ': €., r v EXISTING CONTOURS �" 1 w PROPOSED CONTOURS 9,8 8 � f{. \ RELOCATE cc EAM � •,.—. _ �a ' \� PUBUL MAY t , -'-- -- -- —� — — — ---- � ——— ——— ---- --- ---; PROPOSED PONDS _ \ ._ 70`PUBIK CREEII YIAY COIdWDR t L0Wtl00R •. .._- --n•- , , c . , ,._ FND-MOOT __.." : :.:' •z;^ -......_ C(3:S5 STWP 11NREA0 0144M - ::.fN65 B A 3AR _.... ,f_ STRIIa N c NO E 0 ........ Vortk�=:l9th..Avar�ue.- _.............. ..................... .. 77.7 FND MOOT 6' TML ALUMINUM DAP 6' TRAIL ( EXHIBIT 'C' i _ 3:1 2.0' DEEP �31 3:1 �25' EEP �31 GRASS LINED GRASS LINED SMENTISM MORRISON suffitym 5' BDtTQM 15' BOTTOM MAIERLE,INC. PLANtim GRAPHIC SCALE OCAP a 120 CFS THE GALLATIN CENTER txAP a,a 450 CFS -4.Jr-pl% -D-wd0—p.,<y 0100 - 100 CFS Q100 - 360 CFS rn e.1113 m T.Vd,m etd e®.In,n sont•F—tael sn-am Fc N0e1 SV-ttn REMSION DATE: i>IN zoo a DRAWN BY: CAIW RDAM EMVCNtSD/30/98. TYPICAL CHANNEL SECTION DRAINAGE & GRADING TYPICAL CHANNEL SECTION it'X17'Scale: i inch MO ft. TnRu/ /S /b u93 ooa RANSNTT Contour Int—o' FOR WEST CATRON CREEK CKM FOR EAST CATRON CREEK piENO.: BY: JOD NO.: 2393.006.030.0310 SHEET 2 OF 2 EXHIBIT 'A' THE GALLA TIN CENTER CONTRIBUTING AREAS & POND LOCATIONS 0 o j � o �pv ! � p � /�\ s� � I -N.27th-A w— FL.T T 24 56.35'aq ft. L 7 3 6,1 3 1.34 3,34 152, n--, \'.v LOT 20 5V 3 D 263.17 9�.ft. ,, 188,540 q.ft. 6.04 D2 D3 �I`( ( I I I ec ee \. I: ...�. <.... �j+ 01,1 S 111L,i-I 1.04 "CO"ON 11 M -de- 21483 2 117 11 611 1 ul�277 LOT 26 17 x eL,4 WU a 1! 4.23 157,091.4.ft. 10.86 D �l, L O'� 5 "POND 4 r j__ 3.61 \- - - - - - - - — r .-f� - - 37.486 q.ft. 0 1.18 ------------------------------ 1� LOT 006 562 q.ft ;POND 3 FS III I•II 43.10 q,ft; C A 10 li '6N 1;0T 12 2 LOT 11 EL- 2 POND 5 ZL 600"G JL 2 , 0 13.78 q- V 00...... z EAST E LOT 27 6V 4 j L07 13 ------ ----- rol__ > North-lgth Avenue- K 11 - ---------------- th COMMUNITY PONDS SUBAREA AREA OUTFALL POND VOLUME OUTLET STRUCTURE RELEASE RATE LEGEND (ACRES) (CFT) (CFS) GRAPHIC SCALE 8 6.20 POND 2 5250 1-8" HDPE @ S=1.5% 2.2 SUBAREAS C 2.55 POND 3 1900 1—6" PVC @ S=1.2% 1.2 IN FErr D 16.30 POND 4 18,000 1-12" HDPE @ S=0.2% 3.7 1 1-h. 200 fL E 20.00 POND 5 20500 1-10" HDPE @ S=3.0% 4.8 1l'X17"Scala: I inch = 440 ft. PROPOSED PONDS V Contour Interval MORRISON SURVEMRS LOTS 1,2 & 13 — 27 SHALL HAVE INDIVIDUAL PONDS ON—SITE WITH Pl."Us L IMAIERLEINC. SNM Im LOCATIONS PROPOSED DURING SITE PLAN REVIEW. An knpf,%-0w-d P.-Y (SEE APPENDIX FOR INDIVIDUAL LOT POND COMPUTATIONS.) pAoxim omUd,.1.w*A ft.,aftitr mTrl-Fh..(4*5V-= fec(4005N7-1176 REVISION DATE REVISION DATE. -DRAWN BY: Cmw DATE: 11/18/98 2393/OO6/5TORM/PUD/tXHlBlTA CHECKED BY: DRAWING NO.: Joe No, 2393.006.030.0310 SHEET 1 OF 1 APPENDIX AUGUST 4, 1998 LETTER FROM MDT RUNOFF AND DETENTION POND CALCULATIONS FOR: LOTS 1 &2 COMMUNITY PONDS 2-5 LOTS 8-27 The Gallatin Center P.U.D. 13 THU 02.:26.—Ptl CITY OF DOZ. CAPHEGIE 406 522 236Z P. 01 fol �s NATURE SAVER"'FAX ME140 01016 F, pag tj morimna Departt-nont To of Transportation PO Scm 201,101 Co.10i Co, He/civi A47 f-9620-J.00 Fax I Fax,i August 4, 1998 Debbie Arkell, Assistant Phanning Director Bozeman City-county Planning Office 35 North Bozeman Avenue Bozeman, NIT 5977 f-0640 A U G Subject: The Gallatin Center Subdivision Preliminary Plat CITY- At the preliminary planning level this development along with other planned developments on The corridor indicate future facility improvements to preserve the capacity and safety of both the Valley Center Road and 19'h Avenue corridors will be needed. Such improvements may include addition of turn or general purpose driving lanes, possible si.-nalization and appropriate geometries for the design speed and functional system of the route. MDT currently has no plans to improve this corridor to accommodate the proposed growth, and it would be many years before MDT could obtain funding for these improvements. While the MDT has no current planned projects to accommodate the increased traffic in the corridor,we would expect the functional capacity and safety to be presen-ed before access is permanently approved. Typically, since these types of improvements benefit the developers,the costs for improvements are born by the developers. The MDT is researching tho access control on the.adjacent routes and -ill provide information io the District and the City Planning Office in the near future. Any approaches must be consistent xvith any access control resolutions on the site. Since there are several developments planned for this corridor we Nvouldask for a combined traffic impact statement that collectively reviews all impacts and provides alternatives which will protect the integrity and safety of the corridor. Attached is Chapter Forty-One, "Traffic Impact Studies"of the Montana Tui cEngineering Manual.This chapter should be used as a guideline when performing the corridor analysis. MDT comments on the Grading and Drainage Plan are as follows: • The proposed calculations and features are acceptable. The City of Bozeman should perform the necessary analysis to ensure.the systems will meet City requirements. The combined 50-year design flood capacity of the culverts under East Valley Center Drive is 250 cfs before overtopping the road. These culverts were sized based on the 9 controlled capacity of Baxter Lane, along with the City of Bozeman Stormwater Master of r,i"11 1,01 deter"'lor, f—E—s t3 limit peak- runoff areas. The 15 proposed culverts for The Gallatin Center major drainage system will allow a post- 4, development 25-year flood of 320 cfs through Catron Street, which will then flow to the 7 culverts at Eas't Valley Center Drive. We are concerned that proposed grading activities 9 for these and other developments,as well as increasing culvert capacity at Baxter Lane (or eliminating a detention process),will create potential flooding at East Valley Center Jo Drive. The proposed detention ponds for the storm drain will work for the floods smaller 41 1 T UF' EOZ. CRRNEG I E / r49 �.. Il than the 25-year events, but will not serve to attenuate the larger events. Replacing the existing 246cfs cuIvert at Baxter Lane should be removed from consideration Stor 13 tivater run-off will not be permitted onto roads under State jurisdiction. n} Thank you for the opportunity to review the preliminary plat for this development. If you have questions or need additional information please contact Jim Skinner at(406)444-9233. ar fiS n ra . Strae}, , Chief j Program &Policy Analysis Transportation Planning,Division Attachment ec; Jason Giard, P.E., MDT-Butte District Administrator Rob Bukvich, P.E., MDT-Butte District Engineer Patricia Saindon,MDT-Transportation Planning Division Administrator Lynn Zanto, MDT- Urban Area Supervisor PERMANENT POND CALCULATIONS The Gallatin Center Subdivision Phase 1 MODIFIED RATIONAL METHOD LOT 1 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 27.00 MIN 0.45 HR 2 0.58 0.36 0.6 5 0.87 0.52 0.64 PRE-DEV C= 0.22 10 1.08 0.64 0.65 25 1.30 0.78 0.64 STORM A= 0.64 50 1.56 0.92 0.66 B= 0.65 100 1.72 1.01 0.67 STORM INTENSITY= 1.08 IN/HR PRE-DEV Op= 0.76 CFS POST-DEVELOPMENT BASIN AREA PRE= 3.2 ACRES POST-DEV TC= 14.00 MIN 0.23 HR POST-DEV C= 0.6 STORM INTENSITY= 1.65 IN/HR 10 YR POST-DEV Op= 4.22 CFS DELTA DURATION= 1 MAX VOLUME '-MAXVOLUME'; AVERAGEVOL„ POND VOLUME CALCULATIONS: (CFT) (CFT) (CFT) 4476 57 Triangle Release`;Constant Release DURATION INTENSITY Qp POND VOLUME 'POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 13,30 1.70 4.36 2861.03_ 2351.33 7557.12 14.30 1.63 4.16 2927.77 2400.68 15.30 1.56 3.98 2990.54 2445,93 16.30 1.49 3.82 3049.74 . 2487.50 17.30 1.44 3.68 3105:74 2525.76 18.30 1.38 3.55 3158 84„.; 2561.02 19.30 1.34 3.42 3209.29' 2593.53 20.30 1.29 3.31 3257.31 2623.54 21.30 1.25 3.21 3303.11;,=.;`.. 2651.23 22.30 1.22 3.12 3346,64' 2676.79 23.30 1.18 3.03 3388.67, 2700.37 24.30 1.15 2.95 3428.72 2722.10 25.30 1.12 2.87 3467.11, 2742.12 26.30 1.09 2.80 3503.95 2760.52 27.30 1.07 2.73 3539.33' 2777.42 28.30 1.04 2.67 3573.35 2792.89 29.30 1.02 2,61 3606.08 - 2807.03 30.30 1.00 2.55 3637.60 " 2819.89 31.30 0.98 2.50 3667.96 2831.56 32.30 0.96 2.45 3697,23 2842.10 33.30 0.94 2.40 3725.47 2851.55 34.30 0.92 2.36 3752,72 2859,98 35.30 0,90 2.31 3779.03 2867.43 36.30 0.89 2.27 3804.45 2873.95 37.30 0.87 2,23 3829.01 2879.58 38.30 0.86 2.19 3852.76 2884.36 39.30 0.84 2A6 3875.72 2888.32 40.30 0.83 2.12 3697,94" 2891.49 41.30 0.82 2.09 3919.44 2893.92 42.30 0.80 2.06 3940,24 2895.63 43.30 0.79 2.03 3960.38 2896.64 44.30 0.76 2.00 3979.89 2896.98 45.30 0.77 1.97 3998.78 2896.68 46.30 0.76 1.94 4017.07 2895.77 47.30 0.75 1.91 4034.80 2894.25 48.30 0.74 1.89 4051.97 2892.16 49.30 0.73 1.86 4068.61 2889.50 50.30 0.72 1.84 4084.73 2886.31 51.30 0.71 1.81 4100.35 2882.60 52.30 0.70 1.79 4115.50 2878.38 53.30 0.69 1.77 4130.17 2873.67 54.30 0.68 135 4144.39 2868.48 55.30 0.67 1.73 4158.17 2862.84 56.30 0.67 1.71 4171.53 2856.75 57.30 0.66 1.69 4184.47 2850.22 58.30 0.65 1.67 4197.01 2843.27 59.30 0.64 1.65 4209.16 2835.91 60.30 0.64 1.63 4220.93 . 2828.15 61.30 0.63 1.62 4232.32 2820.01 62.30 0.62 1.60 4243.36 2811.48 63.30 0.62 1,58 4254.05 2802.69 64.30 0.61 1.57 4264.40 c 2793.34 65.30 0.61 1.55 4274.41 2783.74 66.30 0.60 1.54 4284.10 2773.80 MODIFIED RATIONAL METHOD LOT 2 Op=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 27.00 MIN 0.45 HR 2 0.58 0.36 0.6 5 0.87 0.52 0.64 PRE-DEV C= 0.22 10 1.08 0.64 0.65 25 1.30 0.78 0.64 STORM A= 0.64 50 1.56 0.92 0.66 B= 0.65 100 1.72 1,01 0.67 STORM INTENSITY= 1.08 IN/HR PRE-DEV Qp= 0.71 CFS POST-DEVELOPMENT BASIN AREA PRE= 3 ACRES POST-DEV TC= 14.00 MIN 0.23 HR POST-DEV C= 0.8 STORM INTENSITY= 1.65 IN/HR 10 YR POST-DEV Qp= 3.96 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME` AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (CFT) 4196.7 2715 92 g, 3456.35 Triangle Releas6'1;Constant Release DURATION INTENSITY Op POND VOLUME' POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 13.30 1.70 4.09 2682.21 2204.37 7084.80 14.30 1.63 3.90 2744.79 2250.64 15.30 1.56 3,73 2803.63 2293.06 16.30 1.49 3.58 >285913< 2332.03 17.30 1.44 3.45 2911.63' 2367.90 18.30 1.38 3,32 296141 2400.95 19.30 1.34 3.21 3008 71 2431.44 20.30 1.29 3.11 3053 73 2459.57 21.30 1.25 3.01 3096.66 ,' 2485.53 22.30 1.22 2.92 3137 66 2509.49 23.30 1.18 2.84 3176 88 2531.59 24.30 1.15 2.76 3214.42 1,- ' 2551.97 25.30 1.12 2,69 3250.41 2570.74 26.30 1.09 2.63 3284.95 2587.99 27.30 1.07 2.56 3318.13 2603.83 28.30 1.04 2.50 3350.02, ' 2618.34 29.30 1.02 2.45 3380.70 2631.59 30.30 1.00 2.39 3410.25 2643.65 31.30 0.98 2.34 3438.71 2654.59 32.30 0.96 2.30 3466.15 :: 2664.47 33.30 0.94 2.25 3492.63 2673.33 34.30 0.92 2.21 3518.17 2681.23 35,30 0.90 2.17 3542.84, 2688.22 36.30 0.89 2.13 3566.67 2694.33 37.30 0.87 2.09 3569.70 2699.61 38.30 0.86 2.06 3611.96, 2704.08 39.30 0.84 2.02 3633.49 _ 2707.80 40.30 0.83 1.99 3654.32 2710.77 41.30 0.82 196 3674.47 2713.05 42.30 0.80 1.93 3693.98 2714.65 43.30 0.79 1.90 3712.66 2715.60 44.30 0.78 1.87 3731.14 2715.92 45.30 0.77 1.84 3748.85 2715.64 46.30 0.76 1.82 3766.00 2714.78 47.30 0.75 1.79 3782.62 2713.36 48.30 0.74 137 3798.72 _ 2711.40 49.30 0.73 1,75 '3814.32 2708.91 50.30 0.72 1,72 3829.43 2705.92 51.30 0.71 1.70 .3844.08 2702.44 52.30 0.70 1.68 3858.28' 2698.48 53.30 0.69 1.66 3872.04 2694.06 54.30 0.68 1.64 3885.37 2689.20 55.30 0.67 1.62 3898,29 2683.91 56.30 0.67 1.60 3910.81 2678.20 57.30 0.66 1.58 3922.94, 2672.08 58.30 0.65 1.56 3934.70 2665.57 59.30 0.64 1.55 3946.09 2658.67 60.30 0.64 1.53 3957.12 2651.39 61.30 0.63 1.51 3967.86 2643.76 62.30 0.62 1.50 3978.15 2635.76 63.30 0.62 1.48 3988.17 2627.43 64.30 0.61 1,47 3997.87 >^ " 2618.76 65.30 0.61 1.45 4007.26 2609.76 66.30 0.60 1.44 :4016.35,_ 2600.44 MODIFIED RATIONAL METHOD SUBAREA. B Qp=CIA PRE-DEVELOPMENT I=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ ;6.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) ;_A B ORE-DEV TC= ;, ':13.30 MIN 0.22 HR 2 0.89 0.36 0.6 5�;, 1.36 ;0.52 0.64 PRE-DEV C= b.2 CJ 1.70 0.64 0.65 25 2.05 0.78 :',0.64 STORM A . 0.64 50 2.49 0.92 `,0.66 B _ 0.65 100 2.77 -1.01 0.67 STORM INTENSITY= 1.70 IN/HR PRE-DEV Qp= 2.11 CFS POST-DEVELOPMENT BASIN AREA PRE= 6.2 ACRES POST-DEV TC= 6.70 MIN 0.11 HR POST-DEV C= 0.85 STORM INTENSITY= 2.66 IN/HR 10 YR POST-DEV Qp= 14.02 CFS DELTA DURATION= 1 MAX VOLUMEW MAX VOLUME":, AVERAGE VOL POND VOLUME CALCULATIONS: '(CFT) t T) (� 3 7953 58 6589.57w1 �- Triangle Releasg Constant Release 2. DURATION INTENSITY Op POND VOLUME;:POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) ;(CFT) ,' i (CFT) (CFT) 6.37 2.75 14.50 4708 75 ,i 4004.36 15557.04 7.37 2.50 13.19 4935 50 A'} 4180.04 8.37 2.30 12.14 "'5137 64 :%( 4330.53 9.37 2.14 11,28 �5319.88 %;.` 4460.64 10.37 2.00 1Q56 543560 4573.81 11.37 1.89 9.95 '5637 36 ti.p 4672.68 12.37 1.79 9.42 5777 15 ' ;' 4759.24 13.37 1.70 8.95 5906 52 y '3 4835.10 14.37 1.62 8.54 6026.•72?` 4901.55 15.37 1.55 8.18 6138 80 r 4959.63 16.37 1.49 7.85 6243 60 5010.22 17.37 1.43 7.55 "6341 5054.07 18.37 1.38 7.28 643414 J, 5091.79 19.37 1.33 7.03 6521 03;: ' 5123.93 20.37 1.29 6.81 .6%02 95 '= 6150.95 21.37 1.25 6.60 6680 31_ ;',r, 5173.26 22.37 1.22 641 6753.44 ' ''<+ 5191.21 2337 1.18 6.23 6322.66 .;; 5205.13 24.37 1.15 6.06 6888.25';;:.:,. 5215.28 25.37 1.12 5.90 6950 43 5221.92 25.37 1.09 5.76 7000 44 ';'i 5225.28 27.37 1.07 5.62 7065 47 .:5`:' 5225.56 28.37 1.04 5.49 7118.64'•.''': 5222.93 29.37 1.02 5.37 _7169.27 5217.57 30.37 1.00 5.25 7217.36 5209.62 31.37 0.98 5,14 7263 OS 5199.23 32.37 0.96 5.04 7306.56 5186.52 33.37 0.94 4.94 7347.92 5171.61 344.37 0.92 4.85 '7387.26 5154.60 35.37 0.90 4.76 7424.67 _ ;ij '5135.59 36.37 0.89 4.67 7460 25. 5114.68 37.37 0.87 4.59 7494.07 5091.95 38.37 0.86 4.51 7526 22,.' .;q 5067.48 39.37 0.84 4.44 7556 76 5041.35 40.37 0.83 4.36 7585.77;f; `I 5013.61 41.37 0.82 4.30 7613.29;;;' 4984.34 42.37 0.80 4.23 7639.40-i - 4953.60 43.37 0.79 4.17 7664.ls,;.` i 4921.44 44.37 0.78 4.10 - 76a7 58 4887.92 45.37 0.77 4.05 770975? 4853.09 45.37 0.76 399 7730.71::',;"r. 4816.98 47.37 0.75 3.93 775049? ,i 4779.66 43.37 0.74 3.8a 7769.14.'r 4741.16 49.37 0.73 383 7786.69 i">.'; 4701.51 50.37 0.72 3.78 78031Bj- ', 4660.77 51.37 0.71 373 7618.65 '`:,;y 4618.95 52.37 0.70 3.68 7833.12 ;'; 4576.11 , $3.37 0.59 3,64 4846.64�;;��. 4532.26 54.37 0.63 3.60 7859.22 ? ? 4487.44 55.37 0.67 3,55 7870.90 4441.68 56.37 0.67 3.51 788171 a '` 4395.01 57.37 0.66 3.47 7891,66 j 4347.45 58.37 0.65 3.43 '7900.79,i;,,?'.q 4299.02 OUTLET STRUCTURE DESIGN POND: POND 2 REQUIRED VOL= 5250 (CFT) QPRE= 2.20 (CFS) DIAMETER= 8 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 1.70 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.016 (FT/FT) Ke= 0.50 FLOW OUT= 2.20 (CFS) AVE SURF AREA= 3086 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0,0000 1.82 0.0010 1.85 0.0020 1.87 0.0030 1.90 0.0040 1.92 0.0050 1.95 0.0060 1.97 0.0070 2.00 0.0080 2.02 O.0090 2.04 0.0100 2.07 0.0110 2.09 0.0120 2.11 0.0130 2.14 0.0140 2.16 0.0150 2.18 0.0160 2.20 0,0170 2.22 0.0180 2.25 0.0190 2.27 0.0200 2.29 0.0210 2.31 0.0220 2.33 0.0230 2.35 0.0240 2.37 0.0250 2.39 0.0260 2.41 0.0270 2.43 0.0280 2.45 0.0290 2,47 0,0300 2.49 0.0310 2.51 0.0320 2.53 0.0330 2.55 0.0340 2.57 0.0350 2.58 O.0360 2.60 0.0370 2,62 0.0380 2.64 0.0390 2.66 0.0400 2.66 0.0410 2.69 0.0420 2.71 0.0430 2.73 0.0440 2.75 0.0450 2.76 0.0460 2.78 0.0470 2.80 0.04B0 2.82 0.0490 2.83 0.0500 2.85 0.0510 2.87 0.0520 2.88 0.0530 2.90 0.0540 2.92 0.0550 2.93 0.0560 2.95 0.0570 2.96 0.0580 2.98 0.0590 3.00 0.0600 3.01 O0610 3.03 0.0620 3.04 0.0630 3.06 0.0640 3.08 0.0650 3.09 0.0660 3.11 0.0670 3.12 0.0680 3.14 0.0690 3.15 OPMODIFIED RATIONAL METHOD SUBAREA. C ®A/0 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 2.55 ACRES STORM EVENT NTENSIT .' STORM i COEFF d (YR) (IN/HR) A B PRE-DEV TC= 850 MIN 0.14 HR 2 1.16 0.36 0.6 5 1.82 0.52 0.64 PRE-DEV C= 0.2` �'10 2.28 0.64 - 0.65 �W 2.72 0.78 0.64 STORM A=' '.0.64` 50 3.34 0.92 0.66 B= 0.65 100 3.74 1,01 0.67 STORM INTENSITY= 2.28 IN/HR PRE-DEV Op= 1.16 CFS POST-DEVELOPMENT BASIN AREA PRE= 2.55 ACRES POST-DEV TC= 4.30 MIN 0.07 HR POST-DEV C= 0.85 STORM INTENSITY= 3.55 IN/HR 10 YR POST-DEV Op= 7.69 CFS DELTA DURATION= 1 MAX VOLUME MAXVOCUME= AVERAGE VOL` POND VOLUME CALCULATIONS: (CFT) (CFT); (CFT) - I� 2796 12 1836.78 ryms 23f645 „y �r{/1 Triangle Release 11. Constant Release DURATION INTENSITY Qp POND VOLUME,I POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) - , (CFT) (CFT) 4.09 3.67 7.96 1657A2' 1408.81 6398.46 5.09 3.18 6.90 1777.86 1501.07 6.09 2.83 6.14 1879 51 1574.10 7.09 2.57 5.56 1967.25 . 1632.86 8.09 2,35 5,10 2044,19, 1680.55 9.09 2.18 4.73 2112.47' 1719.32 10.09 2.04 4.42 2173760 1750.76 11.09 1.92 4.16 2228.73 - 1776.01 12.09 1.81 3.93 2278,73 1795'97 13.09 1.72 3.73 2324.27, 1811.34 14.09 1.64 3.56 2365.91'' 1822.69 15.09 1.57 3.40 2404.10' 1830.47 16.09 1.51 3.26 2439.20, 1835.06 17.09 1.45 3.14 2471.53' 1836.78 18.09 1.40 3.02 2501.35, ,`' 1835.90 19.09 1.35 2.92 2528,88'' 1832.66 20.09 1.30 2.83 2554.33 1827.26 21.09 1.26 2.74 2577.85 1819.86 22.09 1.23 2.66 2599.59 1810.62 23.09 1.19 2.58 2619.69 1799.68 24.09 1.16 2.51 2638.27 1787.16 25.09 1.13 2.45 2655.42 1773.15 26.09 1.10 2.38 2671.24 1757.77 27.09 1.07 2.33 2685,82 ' 1741.08 28.09 1.05 2.27 2699.22 1723.18 29.09 1.02 2.22 2711,51 1704.13 30.09 1.00 2.17 2722.76 1683.99 31.09 0.98 2.13 2733,03 1662.83 32.09 0.96 2.08 2742.36 1640.69 33.09 0.94 2.04 2750.81 1617.63 34.09 0.92 2.00 2758.41 1593.69 35.09 0.91 1.97 2765,21 1568.91 36.09 0.89 1.93 2771.24 1543.34 37.09 0.87 1.90 2776.54 1517.00 38.09 0.86 1.86 2781.15 1489.94 39.09 0.85 1.83 2785.09 1462.18 40.09 0.83 1.80 2788,38' 1433.75 41.09 0.82 1.77 2791.07 .' 1404.67 42.09 0.81 1.75 2793.16 .• 1374.99 43.09 0.79 1.72 2794.69, 1344.71 44.09 0.78 1.69 2795.67, ' 1313.85 45.09 0.77 1.67 2798.12 ;, 1282.45 46.09 0.76 1.65 2796.08 1250.53 47.09 0.75 1.62 2795.54 1218.09 48.09 0.74 1.60 2794 53 1185.15 49.09 0.73 1.58 279307 1151.75 50.09 0.72 1.56 279116 1117.88 51.09 0.71 1.54 2788.84 1083.56 52.09 0.70 1.52 278610 1048.82 53.09 0.69 1.60 2782,96 1013.65 54.09 0.68 1.48 2779.44 978.08 55.09 0.68 1.47 2775 54 942.12 56.09 0.67 1.45 2779 27 905.78 57.09 0.66 1.43 ,2766.66 869.07 OUTLET STRUCTURE DESIGN POND: POND 3 REQUIRED VOL= 1900 (CFT) QPRE= 1.16 (CFS) DIAMETER= 6 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 1.70 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.012 (FT/FT) Ke= 0.50 FLOW OUT= 1.16 (CFS) AVE SURF AREA= 1118 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 1.01 0.0010 1.03 0.0020 1.04 0.0030 1.05 0.0040 1.06 0.0050 1.08 0.0060 1.09 0.0070 1.10 0.0080 1.11 0.0090 1.12 0.0100 1.13 0.0110 1.15 0.0120 1.16 0.0130 1.17 0.0140 1.18 0.0150 1.19 0.0160 1.20 0.0170 1.21 0.0180 1.22 0.0190 1.23 0.0200 1.24 0.0210 1.25 0.0220 1.26 0.0230 1.27 0.0240 1.28 0.0250 1.29 0.0260 1.30 0.0270 1.31 0.0280 1.32 0.0290 1.33 0.0300 1.34 0.0310 1.35 0.0320 1.36 0.0330 1.37 0.0340 1.38 0.0350 1.39 0.0360 1.40 0.0370 1.41 0.0380 1.42 0.0390 1.43 0.0400 1.44 0.0410 1.44 0.0420 1.45 0.0430 1.46 0.0440 1.47 0.0450 1.48 0.0460 1.49 0.0470 1.50 0.0480 1.51 0.0490 1.51 0.0500 1.52 0.0510 1.53 0.0520 1.54 0.0530 1.55 0.0540 1.56 0.0550 1.56 0.0560 1.57 0.0570 1.58 0.0580 1.59 0.0590 1.60 0.0600 1.60 0.0610 1.61 0.0620 1.62 0.0630 1.63 0.0640 1.64 0.0650 1.64 0.0660 1.65 0,0670 1.66 0.0680 1.67 0.0690 1.68 MODIFIED RATIONAL METHOD LOT 8 FRONT '5-tASAPE55A Qp=CiA �f io PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 16.3 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 27.00 MIN 0.45 HR 2 0.58 0.36 0.6 0.87 0.52 0.64 PRE-DEV C= 0,21 6 1.08 0.64 0.65 25 1.30 0.78 0.64 STORM A= 0.64 50 1.56 0.92 0.66 B= 0.65 100 1.72 1.01 0.67 STORM INTENSITY= 1.08 IN/HR PRE-DEV Qp= 3.68 CFS POST-DEVELOPMENT �w BASIN AREA PRE= 16.3 ACRES POST-DEV TC= 14.00 MIN 0.23 HR POST-DEV C= 0.85 STORM INTENSITY= 1,65 IN/HR 10 YR POST-DEV Qp= 22.84 CFS DELTA DURATION= 1 MAX VOLUME "MAX VOLUME l �AVERAGE,VOL POND VOLUME CALCULATIONS: (CFT) (CFT) x (CFT) ._ 25943 65 16955 04 POND)TriRelease'angle I Constant Release P-4 DURATION INTENSITY Qp POND VOLUME,1 POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) ,(GFT} (CFT) (CFT) 13.30 1.70 23.61 .15825 17 13292.37 40899.96 14.30 1.63 22.52 1619889t 13578.91 15.30 1.56 21.55 ''16551 07 13843.36 _ 16.30 1.49 20.69 16' 99 14088.03 .1 17.30 1.44 19.90 17199 56 14314.88 18.30 1.38 19,19 '1749942 a i, 14525.57 1119.30 1.34 18.53 17784 94 14721.54 20.30 129 1794 18057 35 14904.01 21.30 1.25 17.38 '18317 68 �1 15074.05 22.30 1.22 16.87 18566 87 4 15232.62 23.30 1.18 16.40 1680572 15380,55 24.30 1.15 15.96 19034 95 "') 15518.57 25.30 1.12 15.54 19255.22 15647.35 26.30 1.09 15.16 19467.10, 15767.47 27.30 1.07 14.79 19671 10 15879.48 28.30 1.04 14.45 19867 71 ,>�� 15983.85 29,30 1.02 14.13 20057 34 16081.03 30.30 1.00 13.82 20240 39 16171.40 31.30 0.98 13.54 2 0417 20 16255.34 32.30 0.96 13.26 2058811 16333.18 33.30 0.94 13.00 20753.42 a 16405.23 34.30 0.92 12.75 20913 39 16471.77 35.30 0.90 12,52 21068 29 16533.06 36.30 0.89 12.29 ,21Z1634 16589.33 37.30 0.87 12,08 2136377 , 16640.83 38.30 0.86 11.87 '21504 78 ) 16687.75 39,30 0.84 11.67 `21641 56 16730.29 40,30 0.83 11.49 21774 28 =_ 16768.63 41.30 0.82 11.30 2190311 16802.94 42.30 0.80 11.13 ,22028 21 ,„ 16833.38 43.30 0.79 10.96 22149 71 "'< 16860.09 44.30 0.78 10.80 22267 75 16883.23 45.30 0.77 10.64 22382 47 t'''j 16902.91 46.30 0.76 10.49 122493.98',t") 16919.27 47.30 0.75 10,35 "22602 39 16932.42 48.30 0.74 10.21 22707 82 16942.47 49.30 0.73 10.07 22810 36 16949.52 50.30 0.72 9.94 2291012 16953.68 51.30 0.71 9.82 2300717 16955.04 52.30 0.70 9.70 2316161 16953.68 53.30 0.69 9.58 23193 52 16949.70 54.30 0.68 9A6 23282 98 +A 16943.16 55.30 0.67 9.35 23370 05 16934.16 56.30 0.67 924 234.54 82 1692176 67.30 0.66 9.14 23537 35 16909.02 58.30 0.65 9.03 23617 71 xA 16893.03 59.30 0.64 8.94 '23695 94, 16874.83 60.30 0.64 884 '23772 12 16854.50 61.30 0.63 8,74 ,.2384630 ,,: 16832.08 62.30 0.62 8.65 23918 53 16807.64 63.30 0.62 8.56 23988 87 16781.22 64.30 0.61 8.48 2405736 16752.89 65.30 0.61 8,39 24124 04 16722.67 66.30 0.60 8.31 24168 98 i 16690.64 OUTLET STRUCTURE DESIGN POND: POND 4 REQUIRED VOL= 18000 (CFT) QPRE= 3.68 (CFS) DIAMETER= 12 (INCHES) LENGTH OF PIPE= 20 (FT) HEAD WATER= 1.60 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.002 (FT/FT) Ke= 0.50 FLOW OUT= 3.69 (CFS) AVE SURF AREA= 11250 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 3.57 0.0010 3.63 0.0020 3.69 0.0030 3.75 0.0040 3.80 0.0050 3.86 0.0060 3.91 0.0070 3.97 0.0080 4.02 0,0090 4.07 0.0100 4.12 0.0110 4.18 0.0120 4.23 0.0130 4.28 0.0140 4.33 0.0150 4.37 0.0160 4.42 0.0170 4A7 0.0180 4.52 0.0190 4.56 0.0200 4.61 0.0210 4.66 0.0220 4.70 0.0230 4.75 0.0240 4.79 0.0250 4.84 0.0260 4.88 0.0270 4.92 0.0280 4.97 0.0290 5.01 0,0300 5.05 0.0310 5.09 0.0320 5.13 0.0330 5.18 0.0340 5.22 0.0350 5,26 0.0360 5.30 0.0370 5.34 0,0380 5.38 0.0390 5.42 0.0400 5.46 0.0410 5.49 0.0420 5.53 0.0430 5.57 0.0440 5.61 0.0450 5.65 0.0460 5.68 0.0470 5.72 0.0480 5.76 0.0490 5.80 0.0500 5.83 0.0510 5.87 0.0520 5.91 0.0530 5.94 0.0540 5.98 0.0550 6.01 0.0560 6,05 0.0570 6.08 0.0580 6.12 0.0590 6.15 0.0600 6.19 0.0610 6.22 0.0620 6.25 0.0630 6.29 0.0640 6.32 0.0650 6,36 0.0660 6.39 0.0670 6.42 0.0680 6.46 0.0690 6.49 MODIFIED RATIONAL METHOD SUBAREA. E Qp=CIA PRE-DEVELOPMENT I=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= r'-20.ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B ORE-DEV TC= ?, 23.00 MIN 0.38 HR 2 0.64 0.36 0.6 5 0.96 0.52 0.64 PRE-DEV C= 0.2 CID 1.19 0.64 0.65 25 1.44 0.78 `' 0.64 STORM A--- 0.64 50 1.73 0.92 0.66 B "0.65 100 1.92 1.01 0.67 STORM INTENSITY= 1.19 INIHR PRE-DEV Qp= 4.77 CFS POST-DEVELOPMENT BASIN AREA PRE= 20 ACRES POST-DEV TC= 3, ;.12.00 MIN 0.20 HR POST-DEV C= 0.85 STORM INTENSITY= 1.82 IN/HR 10 YR POST-DEV Qp= 30.97 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME AVERAGE VOL j POND VOLUME CALCULATIONS: (CFT) (CFT) �3101911 20345Rela 2568210 z Triangle Release {Constant Release DURATION INTENSITY Qp `POND VOLUME POND VOLUME RETENTION VOL (MiN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 11.40 1.88 32,02 ,18550 97 e', 15711.91 50184.00 12.40 1.78 30.32 19061.69 =`s 16108.39 13.40 1.70 28.83 19534 38' =;3 16470.61 14.40 1.62 27.51 19987 40 1'.', 16802.69 15.40 1.55 26.34 20409 32 tiv`J' 17107.99 16.40 1.49 25.28 20E07 86 -; 17389.31 17.40 1.43 24.33 21185 33` 17649.01 18.40 1.38 23.46 i+'%:21543.69' zy 17889A0 t 19.40 1.33 22.67 21884 63,' :1 18111.30 20.40 1.29 21.94 .`�22209.61 ��ly 18317.10 21.40 1.25 21.20 18507.79 22.40 1.21 20.64 22016.62 18684.53 23.40 1.18 20.06 =2310074; 18848.32 24.40 1.15 19.53 2337116, Q 19000.06 25.40 1.12 19.02 23634.64', 19140.54 26.40 1.09 18.55 23885.89 19270.49 27.40 1.07 18.11 24127.55`• 19390.56 23A0 1.04 17.69 24360.16' : 19501.33 29.40 1.02 17.30 24584.31,y;% ' 19603.32 30.40 1.00 16.93 24800.40 : 19697.03 31.40 0,97 16.57 •,.25008.88' s 19782.90 32.40 0.96 16.24 25210.16 `,' 19861.34 33.40 0.94 15,92 25404.60 F 19932.71 34,40 0.92 15.62 :25592.52 ''`: 19997.36 35.40 0.90 15.33 25774.25_; A':' 20055.61 36.40 0.89 15.06 ,25950.06 s 20107.75 37.40 0.87 14.79 `26120.23.• ., 20154.06 38,40 0.86 14.54 26264.99, 20194.79 39.40 0.84 14.30 26444.59 20230.17 40.40 0.83 14,07 26599.23, 20260.43 41.40 0.81 13E5 - 26749.'It"° 20285.77 42.40 0.63 13.63 26894.43.� - 20306.39 43.40 0.79 13.43 27035.35 20322.46 44.40 0.78 13.23 .27172.06 20334.16 45.40 0.77 13.04 27304.69 20341.65 46.40 0.76 12 E6 27433.40 20345.08 47.40 0.75 1268 27558.33 20344.59 43,40 0.74 12.51 27679,61 20340.32 49.40 033 12.35 27797.35 '>' 20332.39 50.40 0.72 1219 27911.69 20320.93 51.40 0.71 1203 ".26022.72 '.s 20306.04 52.40 0.70 1183 28130.56 :',•i! 20287.84 53.40 0.69 11.74 28235.31 20266.43 54.40 0.68 11.60 ',28337.05 - 20241.91 55.40 0.67 11.46 28435.88 20214.37 56.40 0.67 11.33 28531.89 , a 20183.90 57.40 0.68 1120 28625.16 "; 20150.59 68,40 0.65 11,07 i"28715,77 20114.51 59.40 0.64 10 95 ..` 28803.78 z ? 20075.74 60.40 0.64 10.03 28889.28 j 20034.36 61.40 0.63 10.72 28972.34 19990.44 62.40 0.62 1061 ;29053.00 •-.f 14944.04 63.40 0.62 10 50 29131.35 ,'-1 19895.23 64.40 0.61 10.39 f„'.29207.44 <- 19844.08 OUTLET STRUCTURE DESIGN POND: POND 5 REQUIRED VOL= 20500 (CFT) QPRE= 4.77 (CFS) DIAMETER= 10 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 2.50 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.030 (FT/FT) Ke= 0.50 FLOW OUT= 4.72 (CFS) AVE SURF AREA= 8200 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 3.81 0.0010 3.84 0.0020 3.87 0.0030 3.91 0.0040 3.94 0.0050 3.97 0.0060 4.01 0.0070 4.04 0.0080 4.07 0.0090 4.10 0.0100 4.13 0.0110 4.17 0.0120 4.20 0.0130 4.23 0.0140 4.26 0.0150 4.29 0.0160 4.32 0.0170 4.35 0.0180 4.38 0.0190 4.41 0,0200 4.44 0.0210 4.47 0.0220 4.50 0.0230 4.53 0.0240 4.55 0.0250 4.58 0.0260 4.61 0.0270 4.64 0.0280 4.67 0.0290 4.69 0.0300 4.72 0.0310 4.75 0.0320 4.78 0.0330 4.80 0.0340 4.83 0.0350 4,86 0.0360 4.89 0.0370 4.91 0.0380 4.94 0.0390 4.96 0.0400 4.99 0.0410 5.02 0.0420 5.04 0.0430 5.07 0.0440 5.09 0.0450 5.12 0.0460 5.15 0.0470 5A7 0.0480 5.20 0.0490 5.22 0.0500 5.25 0.0510 5.27 0.0520 5.30 0.0530 5.32 0.0540 5.34 0.0550 5.37 0.0560 5.39 0.0570 5.42 0.0580 5.44 0.0590 5.46 0.0600 5.49 0.0610 5.51 0.0620 5.54 0.0630 5.56 0.0640 5.58 0.0650 5.61 0.0660 5.63 0.0670 5.65 0.0680 5.68 0.0690 5.70 MODIFIED RATIONAL METHOD LOT 10 Qp=CIA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 4.5 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 15.00 MIN 0.25 HR 2 0.83 0.36 0.6 5 1.26 0.52 -0.64 PRE-DEV C= 0.2 ® 1.58 0.64 0.65 25 1.89 0.78 0.64 STORM A=- 0.64 50 2.30 0.92 0.66 8= 0.65 100 2.56 1.01 0.67 STORM INTENSITY= 1.58 IN/HR PRE-DEV Qp= 1.42 CFS POST-DEVELOPMENT BASIN AREA PRE= 4.5 ACRES POST-DEV TC= 10.00 MIN 0.17 HR POST-DEV C= 0.85 STORM INTENSITY= 2.05 IN/HR 10 YR POST-DEV Qp= 7.85 CFS DELTA DURATION= 1 MAX'VOLUME�MAX VOLUME 1;AVERAGE UOL POND VOLUME CALCULATIONS: (CFT) (CFT) 5917 01 3826.27_ -- 'Triangle Retease�t Constant Release DURATION INTENSITY Qp POND VOLUME, POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 9.50 2.12 8.11 3793 74 i 3112.84 11291.40 10.50 1.99 7.60 3916.01 3202.57 11.50 1.87 7.16 4028 38.,,,,,. 3282.06 12.50 1.77 6.79 4132.21 3352.73 13.50 1.69 6.45 4228.62 3415.71 14.50 1.61 6.16 4318 49 '' 3471.92 15.50 1.54 5.90 4402.55 ,s� 3522.11 16.50 1.48 5.67 448140 3566.90 17.50 1.43 5.45 - 4555.56 ti 3606.81 18.50 1.38 5.26 4625 47 ,;( 3642.31 19.50 1.33 5.08 4691.48 >; 3673.77 20.50 1.29 4.92 4753.94 3701.52 21.50 1.25 4.77 4813.12 3725.86 22.50 1.21 4.63 4869.26 3747.05 23.50 1.18 4.50 4922.60 3765.30 24.50 1.15 4.38 4973 32:; ! 3780.84 25.50 1.12 4.27 _.5021.59 3793.82 26.50 1.09 4.16 5067 58 3804.42 27.50 1.06 4.06 ,,511l.A " 3812.77 28.50 1.04 3.97 r5153 25 =' 3819.02 29.50 1.02 3.88 '519317 3823.29 30.50 0.99 3.80 523129 3825.67 31.50 0.97 3.72 5267 71;;""- 3826.27 32.50 0.95 3.65 5302 52 3825.19 33.50 0.93 3.58 5335 80 ' 3822.50 34.50 0.92 3.51 5367.62 ,,; 3818.29 35.50 0.90 3.44 5398.05s;, 3812.62 36.50 0.88 3.38 5427 16 3805.57 37.50 0.87 3.32 5455 00,, 3797.18 38.50 0.85 3.27 5481.63 3787.54 39.50 0.84 3.21 5507.10 3776.67 40.50 0.83 3.16 5531 47�1- s 3764.64 41.50 0.81 3.11 ''5554.77 -t 3751.49 42.50 0.80 3.06 i5577.04' 3737.27 43.50 0.79 3.02 5598 38 `; 3722.01 44.50 0.78 2.97 5618 67 3705.76 45.50 0.77 2.93 563811 3688.55 46.50 0.76 2.89 5656 66. ', 3670.42 47.50 0.74 2.85 5674 36 3651.39 48.50 0.73 2.81 569125 3631.50 49.50 0.73 2.77 '5707 34 .":a 3610.78 50.50 0.72 2.74 5722.67 ."_'; 3589.26 51.50 0.71 2.70 5737 26 s� 3566.95 52.50 0.70 2.67 5751 13 3543.89 53.50 0.69 2.64 5764 31's .� 3520.10 54.50 0.68 2.61 �5776 81 � 3495.59 55.50 0.67 2.58 5786 66 3470.40 56.50 0.67 2.55 5799 88 w`;j 3444.54 57.50 0.66 2.52 5810 48 ";'" 3418.04 58.50 0.65 2.49 3390.90 59.50 0.64 2.46 5829 82 ;"' 3363.15 60.50 0.64 2.43 'S83678 ,{ 3334.80 61.50 0.63 2.41 5847 09 T`i 3305.87 a-2 sn n 8q 5118 .5854.86 ., 3276.38 OUTLET STRUCTURE DESIGN POND: POND D1 (REAR LOT 10) REQUIRED VOL= 3900 (CFT) QPRE= 1.41 (CFS) DIAMETER= 6 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 2.00 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.027 (FT/FT) Ke= 0.50 FLOW OUT= 1.41 (CFS) AVE SURF AREA= 1950 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 1.13 0.0010 1.15 0.0020 1.16 0.0030 1.17 0.0040 1.18 0.0050 1.19 0.0060 1.20 0.0070 1.21 0,0080 1.22 0.0090 1.23 0.0100 1.24 0.0110 1.25 0.0120 1.26 0.0130 1.27 0.0140 1.28 0.0150 1.29 0.0160 1.30 0.0170 1.31 0.0180 1.32 0.0190 1.33 0.0200 1.34 0.0210 1.35 0.0220 1.36 0.0230 1.37 0.0240 1.38 0.0250 1.39 0.0260 1.40 0.0270 1.41 0.0280 1.42 0.0290 1.43 0.0300 1.44 0.0310 1.44 0.0320 1.45 0.0330 1.46 0.0340 1.47 0.0350 1.48 0.0360 1.49 0.0370 1.50 0.0380 1.51 0.0390 1.51 0.0400 1.52 0.0410 1.53 0.0420 1.54 0.0430 1.55 0.0440 1.56 0.0450 1.56 0.0460 1.57 0.0470 1.58 0.0480 1.59 0.0490 1.60 0.0500 1.60 0.0510 1.61 0.0520 1.62 0.0530 1.63 0.0540 1.64 0.0550 1.64 0.0560 1.65 0.0570 1.66 0.0580 1.67 0.0590 1.68 0.0600 1.68 0.0610 1.69 0.0620 1.70 0.0630 1.71 0.0640 1.71 0.0650 1.72 0.0660 1.73 0.0670 1.74 0.0680 1.74 0.0690 115 MODIFIED RATIONAL METHOD LOT 9 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)"-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 2.5 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 8.00 MIN 0.13 HR 2 1.21 0.36 0.6 5 1.89 0,52 0.64 PRE-DEV C= 0.21 1 2.37 0.64 0.65 2 2.83 0.78 0.64 STORM A=, 0.64 50 3.48 0.92 0.66 B= 0.65 100 3.90 1.01 0.67 STORM INTENSITY= 2.37 IN/HR PRE-DEV Qp= 1.24 CFS POST-DEVELOPMENT BASIN AREA PRE= 2.5 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.65 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 6.07 CFS DELTA DURATION= 1 MAXVOLUME "'MAXWfUMEi AVERAGEVOL POND VOLUME CALCULATIONS: '2530 33 i6132 2071 72 _, n Triangle ReteaseConstant Release DURATION INTENSITY Qp POND VOLUME-%POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) , .(CFT) (CFT) (CFT) 5.70 2.96 6.28 .171110 1362.97 6273.00 6.70 2.66 5.65 1796 78 1423.14 7.70 2.43 5.17 1874 85 j 1471.20 8.70 2.25 4.77 194170 1509.63 9.70 2.09 4.45 200103 1540.18 10.70 1.96 4.17 2054.08 1584.15 11.70 1.85 3.94 210179 'r` 1582.52 12.70 1.76 3.73 2144 90 1596.04 13.70 1.67 3.55 2163 99 1605.33 14.70 1.60 3.39 2219 53 1610.89 15.70 1.53 3.25 2251 92 3f' 1613.12 16.70 1.47 3.12 2281.48 ;' 1612.35 17.70 1.42 3.01 2308.48" 1608,89 18.70 1.37 2.90 2333.16 1602.97 19.70 1.32 2.81 2356.71 1594.80 20.70 1.28 2.72 2376 33 1584.58 21.70 1.24 2.63 239515 , ' 1572.45 22.70 1.20 2.56 2412.31„, 3 1558.56 23.70 1.17 2,49 2427 93 1543.03 24.70 1.14 2.42 244212 1525.98 25.70 1.11 2.36 2454 97 1507.50 26.70 1.08 2.30 2466 57 1487.69 27.70 1.06 2.25 2476 99 ' 1466.63 28.70 1.03 2,20 2486,3 1444.38 29.70 1.01 2.15 2494 56 1421.02 30.70 0.99 2.10 250184 1396.60 31.70 0.97 2.06 250818 1371.18 32.70 0.95 2.02 2513.64 1344.82 33.70 0.93 1.96 2516,25 1317.55 34.70 0.91 1.94 2522 07 ? 1289A3 35.70 0.90 1.91 252511 1260.49 36.70 0.88 1.87 2527,43 1230.76 37.70 0.87 1.84 2529.05 1200.29 38.70 0.85 1.81 2530 01 1169.11 39.70 0.84 1.78 2530, 1137.24 40.70 0.82 1.75 2536 03 1104.71 41,70 0.81 1.72 252915 1071.55 42.70 0.80 1 70 2527 71 1037.79 43.70 0.79 1.67 2525 72 1003.44 44.70 0.77 1.65 2523 21 3 968.53 45.70 0.76 1.62 2520 20 ,'�s 933.08 46.70 0.75 1.60 251670 897.10 47.70 0.74 1.58 2512 74 860.62 48.70 0.73 1.56 2508,32 823.66 49.70 0.72 1.54 2503 47 786.22 50.70 0.71 1.52 " '2498 19 748.33 51.70 0.71 1.50 2492 51 710.00 52.70 0.70 1.48 248643 $ 671.24 53.70 0.69 1.46 =2479 96 632.06 64.70 0.68 1.44 247313 ) 592.48 55.70 0.67 1.43 2465 93 552.52 56.70 0.66 1.41 2458 39 h �� 512.17 57.70 0.66 1.39 2450 50 '- 471.46 to 7n n at i 1a 430.39 OUTLET STRUCTURE DESIGN POND: POND D2 (REAR LOT 9) REQUIRED VOL= 1700 (CFT) QPRE= 1.24 (CFS) DIAMETER= 6 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 2.00 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.010 (FT/FT) Ke= 0.50 FLOW OUT= 1.24 (CFS) AVE SURF AREA= 850 (SOFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 1.13 0.0010 1.15 0.0020 1.16 0.0030 1.17 0.0040 1.18 0.0050 1.19 0.0060 1.20 0.0070 1.21 0.0080 1.22 0.0090 1.23 0.0100 1.24 0.0110 1.25 0.0120 1.26 0.0130 1.27 0.0140 1.28 0.0150 1.29 0.0160 1.30 0.0170 1.31 0.0180 1.32 0.0190 1.33 0.0200 1.34 0.0210 1.35 0.0220 1.36 0.0230 1.37 0.0240 1.38 0.0250 1.39 0.0260 1.40 0.0270 1.41 0.0280 1.42 0.0290 1.43 0.0300 1.44 0.0310 1.44 0.0320 1.45 0.0330 1.46 0.0340 1.47 0.0350 1.48 0.0360 1.49 0.0370 1.50 0.0380 1.51 0,0390 1.51 0.0400 1.52 0.0410 1.53 0.0420 1.54 0.0430 1.55 0.0440 1.56 0.0450 1.56 0.0460 1.57 0.0470 1.58 0.0480 1.59 0.0490 1.60 0.0500 1.60 0.0510 1.61 0.0520 1.62 0.0530 1.63 0.0540 1.64 0.0550 1.64 0.0560 1.65 0.0570 1.66 0.0580 1.67 0.0590 1.68 0.0600 1.68 0.0610 1.69 0.0620 1.70 0.0630 1.71 0.0640 1.71 0.0650 1,72 0.0660 1.73 0.0670 1.74 0.0680 1.74 0.0690 1.75 MODIFIED RATIONAL METHOD LOT 8 REAR D3 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 2.6 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 8.00 MIN 0.13 HR 2 1.21 0.36 0.6 5 1.89 0.52 0.64 PRE-DEV C= 0.21 Q> 2.37 0.64 0.65 25 2.83 0.78 0.64 STORM A= 0.64 50 3.48 0.92 0.66 B= 0.65 100 3.90 1.01 0.67 STORM INTENSITY= 2.37 IN/HR PRE-DEV Qp= 1.29 CFS POST-DEVELOPMENT BASIN AREA PRE= 2.6 ACRES POST-DEV TC= 7.00 MIN 0.12 HR POST-DEV C= 0,85 STORM INTENSITY= 2.59 IN/HR 10 YR POST-DEV Op= 5.72 CFS DELTA DURATION= 1 'MAX'VOLUME MAXVOLUME? 'AVERAGEVOLI POND VOLUME CALCULATIONS: (CFT),,,, {CFT} - (CFT) 2592 70 1630 1 :Triangle Release> Constant Release DURATION INTENSITY Op POND.VOLUME'POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 6.65 2.67 5.91 1827 64 1416.60 6523.92 7.65 2.44 5.39 1907.29 z 1468.77 8.65 2.25 4.98 1977.25 1510.74 9.65 2.10 4.64 2039 31 1544.37 10.65 1.97 4.35 ,209478 1571.05 11.65 1.86 4.10 2144 66 . '= 1591.81 12.65 1.76 3.89 2189.72 1607.46 13.65 1.68 3.70 '2230 57 1618.64 14.65 1.60 3.54 2267 71 1625.88 15.65 1.53 3.39 230164 1629.61 16.65 1.47 3.25 2332 42 ` 1630.18 17.65 1.42 3.13 23,60 63_ 1627.91 18.65 1.37 3.02 2386.41-;, 1623.04 19.65 1.32 2.92 2409.98 1615.81 20.65 1.28 2.83 �243'1.51 1606.41 21.65 1.24 2.74 .245118 1595.00 22.65 1.21 2.66 246911 1581.73 23.65 1.17 2.59 2485 43 1566.74 24.65 1.14 2.52 2500 26 1550.14 25.65 1.11 2.46 2513 69 1532.05 26.65 1.08 2.40 '2525 82 1512.54 27.65 1.06 2.34 2536.71, , 1491.71 28.65 1.03 2.29 2546 45 ,' 1469.64 29.65 1.01 2.24 2555 10 r'�� 1446.39 30.65 0.99 2.19 2562.72 1422.03 31.65 0.97 2.14 2569.36 1396.62 32.65 0.95 2.10 2575.08 M `: 1370.20 33.65 0.93 2.06 2579.92 `-.) 1342.84 34.65 0.91 2.02 2583.93 t 1314.57 35.65 0.90 1.98 <2587.14 ' .: 1285.44 36.65 0.68 1.952589 69 �a 1255.49 37.65 0.67 1.91 2591 31 ,,,.;._[ 1224.75 36.65 0.85 1.88 '259Z. 4;„- 1193.25 39.65 0.84 1.85 2592.70 1161.04 40.65 0.82 1.82 2592.43 1128.13 41.65 0.81 1.79 2591.54 1094.56 42.65 0.80 1.77 '-259007 1060.34 43.65 0.79 1.74 2568 03 1025.52 44.65 0.78 1.71 2585 44 990.10 45.65 0.76 1.69 2582 34 > 954.11 46.65 0.75 1.67 .2578 72 917.56 47.65 0.74 1.64 2574,62 880.49 48.65 0.73 1.62 2670 05 842.90 49.65 0.72 1.60 2565 03,. 804.82 50.65 0.71 1.58 2559,56 766.25 51.65 0.71 1.562553 673 727.22 52.65 0.70 1.54 '2547 37 687.74 53.65 0.69 1,52 2540 67 3 647.83 54.65 0.68 1.50 ',2533 58 607.49 55.65 0.67 1.49 v252611 566.74 56.65 0.66 1.47 2514.28 s 525.59 57.65 0.66 1.45251014 4 484.05 58.65 0.65 1.44 2501 57 ' ": 442.13 59 RS n Rd 1 Al 'u_IAQ9 71 399 AS OUTLET STRUCTURE DESIGN POND: POND D3 (REAR LOT 8) REQUIRED VOL= 1700 (CFT) QPRE= 1.29 (CFS) DIAMETER= 6 (INCHES) LENGTH OF PIPE= 30 (FT) HEAD WATER= 1.90 (FT) THIS PROGRAM USES THE ENERGY EQUATION TO DETERMINE N= 0.01 THE RELEASE RATE. SLOPE OF PIPE= 0.018 (FT/FT) Ke= 0.50 FLOW OUT= 1.29 (CFS) AVE SURF AREA= 895 (SQFT) SLOPE OF PIPE FLOW OUT (FT/FT) (CFS) 0.0000 1.10 0.0010 1.11 0.0020 1.12 0.0030 1.13 0.0040 1.14 0.0050 1.15 0.0060 1.16 0.0070 1.18 0.0080 1.19 0.0090 1.20 0.0100 1.21 0.0110 1.22 0.0120 1.23 0.0130 1.24 0.0140 1.25 0.0150 1,26 0.0160 1.27 0.0170 1.28 0.0180 1.29 0.0190 1.30 0.0200 1.31 0.0210 1.32 0.0220 1.33 0.0230 1.34 0.0240 1.35 0.0250 1.36 0.0260 1.37 0.0270 1.38 0.0280 1.39 0.0290 1.40 0.0300 1.41 0.0310 1.41 0.0320 1.42 0.0330 1.43 0.0340 1.44 0.0350 1.45 0.0360 1.46 0.0370 1.47 0.0380 1.48 0.0390 1.49 0.0400 1.49 0.0410 1.50 0,0420 1.51 0.0430 1.52 0.0440 1.53 0.0450 1.54 0.0460 1.54 0.0470 1.55 0.0480 1.56 0.0490 1.57 0.0500 1.58 0.0510 1.59 0.0520 1.59 0.0530 1.60 0.0540 1.61 0.0550 1.62 0.0560 1.63 0.0570 1.63 0.0580 1.64 0.0590 1.65 0.0600 1.66 0.0610 1.67 0.0620 1.67 0.0630 1.68 0.0640 1.69 0.0650 1.70 0.0660 1.70 0.0670 1.71 0.0680 1.72 0.0690 1.73 MODIFIED RATIONAL METHOD LOT 13 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)"-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.7 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 9.70 MIN 0.16 HR 2 1.07 0.36 0.6 5 1.67 0.52 0.64 PRE-DEV C= 0.22 10 2.09 0.64 0.65 25 2.50 0.78 0.64 STORM A= 0.64 50 3.06 0.92 0.66 B= 0.65 100 3.42 1.01 0.67 STORM INTENSITY= 2.09 IN/HR PRE-DEV Qp= 0.78 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.7 ACRES POST-DEV TC= 4.00 MIN 0.07 HR POST-DEV C= 0.7 STORM INTENSITY= 3.72 IN/HR 10 YR POST-DEV Op= 4.43 CFS DELTA DURATION= 1 �.,., . . MAX VOLUME" MAX VOLUME` ^,AVERAGE VOL POND VOLUME CALCULATIONS: (CFT)` 7,(CFT) ;(CFT): 1355.58 876 60 1117 09 Triangle Release';Constant Release DURATION INTENSITY Op POND VOLUMC POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) ;(CFT) ' ,x- (CFT) (CFT) 3.80 3.85 4.58 `860.67 ' ;"'S 709.68 3512.88 4.80 3.31 3.93 926.13 756.92 5.80 2.92 3.48 980.22' 792.43 6.80 2.64 3.14 1026,03 819.37 7.80 2.41 2.87 1065.50". 839.74 8.80 2.23 2.65 109§.92 854.87 1130.21� 865.69 9.80 2.06 2.47 10.80 1.95 2.32 1157 04 872.92 11.80 1.84 2.19 1180.92 877.09 12.80 1.75 2.08 1202.27, ` 878.60 13.80 1.66 1.98 1221.39 877.78 14,80 1.59 1.89 1238.55 874.92 15,80 1.52 1.81 1253.96 870.23 16.80 1.46 1.74 1267.80 863.90 17.80 1.41 1.68 1280.23 856.09 18.80 1.36 1.62 1291.37 846.92 19.80 1.32 1.57 1301.33 836.51 20.80 1.27 1.52 1310.21 824.97 21.80 1.24 1A7 1318.09 812.39 22.80 1.20 1.43 1325.65 798.83 23.80 1.17 1.39 1331.16 784.38 24.80 1.14 1.35 1336.47 -'' 769.08 25.80 1.11 1.32 1341.04 753.00 26.80 1.06 1.29 4344:90 736.19 27.80 1.06 1L 26 1348.11 718.68 28.80 1.03 1.23 1350.71, 700.52 29.80 1.01 1.20 1352.72 681.74 30.80 0.99 1.17 1354.18 662.39 31.80 0.97 1.15 1355.13 642.48 32.80 0.95 1.13 1355.58 622.05 33.80 0.93 1.11 1355.55 601.13 34.80 0.91 1.09 1355.09 579.73 35.80 0.90 1,07 1354.19 557.88 36.80 0.68 1.05 1352.89 535.60 37.80 0.86 1.03 1351.20 512.90 38.80 0.85 1.01 1349.14 489.82 39.80 0.64 0.99 1346.73 466.35 40.80 0.82 0.98 1343.97 442.52 41.80 0.81 0.96 1340.89 418.35 42.80 0.80 0.95 1337,49 393.84 43.80 0.79 0.93 1333.79 369.01 44.80 0.77 0 92 1329.79 343.86 45.80 0.76 0.91 1325.52 318.42 46.80 0.75 0.90 1320.97 292.69 47.80 0.74 0.88 1316.17 266.69 48.80 0.73 0.87 1311.11 240.41 49.80 0.72 0.86 1305.81 213.88 50.80 0.71 0.85 1300.27 187.09 51.80 0.70 0,84 1294.51 160.06 52.80 0.70 0.83 `1288.52 132.79 53.80 0.69 0.82 1282.32 105.30 54.80 0.68 0.81 f 1275.92 77.58 55.80 0.67 0.80 1269.31 49.65 MODIFIED RATIONAL METHOD LOT 14 Op=CIA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 9.70 MIN 0.16 HR 2 1.07 0.36 0.6 5 1.67 0.52 0.64 PRE-DEV C= 0.22 10 2.09 0.64 0.65 25 2.50 0.78 0.64 STORM A= 0.64 50 3.06 0.92 0.66 B= 0.65 100 3.42 1.01 0.67 STORM INTENSITY= 2.09 IN/HR PRE-DEV Qp= 0.55 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.2 ACRES POST-DEV TC= 4.00 MIN 0.07 HR POST-DEV C= 0.7 STORM INTENSITY= 3.72 IN/HR 10 YR POST-DEV Qp= 3.13 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME; ;AVERAGE-VOL POND VOLUME CALCULATIONS: (CFT) , '` `(CFT} 956.88 620,18 788.53x - Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) f (CFT) (CFT) 3.80 3.85 3.23 '607 53 500.95 2479.68 4.80 3.31 2.78 653 74 '` 634.30 5.80 2.92 2A5 69192 559.36 6.80 2.64 2.21 724.26 578.38 7.80 2A1 2.02 752.12 592.76 8.80 2.23 1.87 776 42 603.44 9.80 2.08 1.75 797 80 611.08 10.80 1.95 1.64 816 73 616.18 11.80 1.84 1.55 833 59 619.12 12.80 1.75 1.47 846 66 620.18 13.80 1.66 1.40 86216 619.61 14.80 1.59 1.34 874 27 617.59 15.80 1.52 1.28 885.15 614.28 16.80 1.46 1.23 894.92 609.81 17.80 1.41 118 903.69 604.30 18.80 1.36 1.14 911.w 597.82 19.80 1.32 1.11 918.58 590.48 20.80 1.27 1.07 924.85 582.33 21.80 1.24 1.04 930.42 573.45 22.80 1.20 1.01 935.33 563.88 23.80 1.17 0.98 939 64 553.68 24.80 1.14 0.95 943.39 542.88 25.80 1.11 0.93 946.61 531.53 26.80 1.08 0.91 949.34 519.66 27.80 1.06 0.89 951.61 507.30 28.80 1.03 0.87 953.44 494.48 29.80 1.01 0.85 954.86 481.23 30.80 0,99 0.83 955.90 467.57 31.80 0.97 0.81 956.56 - 453.52 32.80 0.95 0.80 956.88 , 439.10 33.80 0.93 0.78 956.86 424.33 34.80 0.91 0.77 956.53 409.22 35.80 0.90 0.75 955.90 393.80 36.80 0.88 0.74 954.98, 378.07 37.80 0.86 0.73 953.79 362.05 38.80 0.85 0,71 952.34' 345.75 39.80 0.84 0,70 950.63 329.19 40.80 0.82 0.69 948.68 - 312.37 41.80 0.81 0.68 946.51 295.30 42.80 0.80 0.67 944.11 278.00 43.80 0.79 0.66 941.50 260.47 44.80 0.77 0,65 938,68 242.73 45.80 0.76 0,64 935.66 224.77 46.80 0.75 0.63 932.45 206.61 47.80 0.74 0.62 929.06 188.25 48.80 0.73 0.61 9Z5.49___ 169.70 49.80 0.72 0,61 z921.75 150.97 50.80 0.71 0.60 917.84 132.06 51.80 0.70 0.59 913.77 112.98 52.80 0.70 0.58 909.55, 93.74 53.80 0.69 0.58 �90517 } 74.33 54.80 0.68 0.57 900.65 54.76 55.80 0.67 0.56 895.98 35.05 56.80 0.66 0,56 89118 15.19 MODIFIED RATIONAL METHOD LOT 15 Cp=CiA PRE-DEVELOPMENT i=a.(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 9.70 MIN 0.16 HR 2 1.07 0.36 0.6 5 1.67 0.52 0.64 PRE-DEV C= 0.22 10 2.09 0.64 0.65 25 2.50 0.78 0.64 STORM A= 0.64 50 3.06 0.92 0.66 B= 0.65 100 3.42 1.01 0.67 STORM INTENSITY= 2.09 IN/HR PRE-DEV Qp= 0.55 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.2 ACRES POST-DEV TC= 4.00 MIN 0.07 HR POST-DEV C= 0.7 STORM INTENSITY= 3.72 IN/HR 10 YR POST-DEV Op= 3.13 CFS DELTA DURATION= t MAX VOLUME".tvMAXVOLUME+ 'AVERAGE VOL POND VOLUME CALCULATIONS: ;(CFT} „(CFT) '_ "(CFT) 956.68 : 620.16._.....,'E Triangle Release;Constant Release DURATION INTENSITY Op POND VOLUME'?`POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT)„ . � (CFT) (CFT) 3.80 3.85 3.23 607.53 i500.95 2479.68 4.80 3.31 278 653.74 `' "i 534.30 5.80 2.92 2.45 :691.92 559.36 6.80 2.64 2.21 724.26 578.38 7.80 2.41 2.02 75212 = 592.76 8.80 2.23 1.87 776 42 603.44 9,80 2.08 1.75 797.80 t 611.08 10.80 1.95 1.64 816 73 616.18 11.80 1.84 1.55 `833.59 619.12 12.80 1.75 1.47 848 66 620.18 13.80 1.66 1.40 662.16', 619.61 14.80 1.59 1.34 674.27 617.59 15.80 1.52 1.28 885:15,,, k 614.28 16.80 1.46 1,23 894.92 - 609.81 17.80 1,41 1,18 903.69 604.30 18.80 1.36 1 A 4 911.55 597.82 19.80 1.32 1.11 918.58 590.48 20.80 1.27 1.07 .924.85-, 'P 582.33 21_80 1.24 1.04 ',936A2 573.45 22.80 1.20 1.01 935.33 563.88 23.80 1.17 0.98 939.64 553.68 24.80 1.14 0.95 943 39;.''.-.-? 542.88 25.80 1.11 0.93 946.61 531.53 26.80 1.08 0.91 949.34 519.66 27.80 1.06 0.89 �'.951.61 507.30 28.80 1.03 0.87 953.44 494.48 29,80 1.01 0.85 954.86 481.23 30.80 0.99 0.83 955.96 467.57 31.80 0.97 0.81 956.56 453.52 32.80 0.95 0.80 "956.88 439.10 33.80 0.93 0.78 956.86 424.33 34.80 0.91 0.77 956.53 409.22 35.80 0.90 0.75 955.90 393.80 36.80 0.88 0.74 954.98 - 378.07 37.80 0.86 0.73 953.79 362.05 38.80 0.85 0.71 952.34 345.75 39.80 0.84 0,70 950.63 ' . 329.19 40.80 0.82 0.69 948.68 312.37 41.80 0.81 0.68 946.51 295.30 42.80 0.80 0.67 944.11 278.00 43,80 0.79 0.66 941.50 260.47 44.80 0.77 0,65 938,68 242.73 45.80 0.76 0.64 935.66 224.77 46.80 0.75 0.63 932.45 206.61 47.80 0.74 0.62 929.06 188.25 48.80 0.73 0.61 925.49, 169.70 49.80 0.72 0,61 921.75 .`.=r° 150.97 50.80 0.71 0,60 917.84, 132.06 51.80 0.70 0.59 913.77' z 112.98 52.80 0.70 0.58 909.55 " 93.74 53.80 0.69 058 905.17 74.33 54.80 0.68 0.57 _900.65 54.76 55.80 0.67 0,56 :895.98 35.05 MODIFIED RATIONAL METHOD LOT 16 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.4 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 10.00 MIN 0.17 HR 2 1.05 0.36 0.6 5 1.64 0,52 0.64 PRE-DEV C= 0.22 10 2.05 0.64 0.65 25 2.46 0.78 0.64 STORM A= 0.64 50 3.00 0.92 0.66 B= 0.65 100 3.35 1.01 0.67 STORM INTENSITY= 2.05 IN/HR PRE-DEV Qp= 0.63 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.4 ACRES POST-DEV TC= 5.00 MIN 0.08 HR POST-DEV C= 0.7 STORM INTENSITY= 3.22 IN/HR 10 YR POST-DEV Qp= 3.15 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME "AVERAGE'VOL' POND VOLUME CALCULATIONS: ,(CFT)' ,„ (CFT) (CFT) 1111.71 710.79911 25,yw_ Irian&Release:I Constant Release DURATION INTENSITY Qp POND VOLUME `POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 4.75 3.33 3.26 744.61 596.54 2892.96 5.75 2.94 2.88 789.93 627.77 6.75 2.65 2.60 828.34 651.79 7.75 2.42 2.37 `861A6 670.29 8.75 2.24 2.19 890,37, 684.39 9.75 2.09 2.04 915.84 694.90 10.75 1.96 1.92 938.45 702.39 11.75 1.85 1.81 9 58.61 707.31 a 12.75 1.75 1.72 976.66 710.02 13.75 1.67 1.63 `992.88 ' . 710.79 14.75 1.59 1.56 1007.46 709.85 15.75 1.53 1.50 1020.60 707.37 16.75 1,47 1A4 1032.44 703.53 17.75 1.41 1.38 1043.11 698.44 18.75 1.36 1.34 1052.71 692.23 19.75 1.32 1.29 1061.34 684.99 20.75 1.28 1.25 1069.08 676.79 21.75 1.24 1.21 1075.99 667.73 22.75 1.20 1.18 1082.14 657.85 23.75 1.17 1.15 1087.58 647.22 24.75 1.14 1,12 1092.36 635.90 25.75 1.11 1.09 1096.53 623.91 26.75 1.08 1.06 1100.12 611.31 27.75 1.06 1.04 1103.17 598.14 28.75 1.03 1.01 1105.71 - 584.42 29.75 1.01 0.99 1107.77 570.19 30.75 0.99 0.97 1109.38 555.47 31,75 0.97 0,95 1110.55 540.29 32.75 0.95 0.93 1111.32 524.68 33,75 0.93 0.91 1111.70 508.65 34.75 0.91 0.89 1111.71 492.22 35.75 0,90 0.88 1111.37 475.42 36.75 0.88 0,86 1110.70 458.26 37.75 0.86 0.85 1109.70 440.76 38.75 0.85 0.83 1108.40 422.92 39.75 0.84 0,82 1106.80 404.77 40.75 0.82 0,81 1104.93 386.32 41.75 0.81 0.79 1102.78 367.58 42.75 0.80 0.78 1100.37, 348.56 43.75 0,79 0.77 1097.71 329.27 44.75 0.77 076 1094.82 309.72 45.75 0.76 0,75 1091.69 289.92 46.75 0.75 0,74 1088.33 269.88 47.75 0.74 0.73 1084.77 249.61 48.75 0.73 0,72 1080.99 229.12 49.75 0.72 0.71 1077.01 208.40 50.75 0.71 0,70 1072.84 187.48 51.75 0.70 069 1068.48 166.36 52.75 0.70 0.68 1063.94 145.03 53.75 0.69 0.67 1059.22 123.52 54.75 0.68 0,67 1054.33 101.82 55.75 0.67 0.66 1049.28 79.94 56.75 0.66 0,65 1044.06 57.89 MODIFIED RATIONAL METHOD LOT 17 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3.8 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 12.00 MIN 0.20 HR 2 0.95 0.36 0.6 5 1.46 0.52 0.64 PRE-DEV C= 0.22 10 1.82 0.64 0.65 25 2.18 0.78 0.64 STORM A= 0.64 50 2.66 0.92 0.66 B= 0.65 100 2.97 1.01 0.67 STORM INTENSITY= 182 IN/HR PRE-DEV Qp= 1.52 CFS POST-DEVELOPMENT BASIN AREA PRE= 3.8 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 7.60 CFS DELTA DURATION= 1 MAX VOLUME MAXVQLUME' ,AVE,RAGEVOc POND VOLUME CALCULATIONS: (CFT) :.'(CFT) (CFT) 3216.38 2056.29 2636,34: _Triangle Release'],Constant Release DURATION INTENSITY Qp POND VOLUME <POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 5.70 2.96 7.86 2154.26 1725.88 7852.32 6.70 2.66 7.08 2265.08._ 1802.77 7.70 2.43 6.47 2361.35 1864.52 8.70 2.25 5.97 2446.09 1914.24 9.70 2.09 5.56 252142 1954.12 10.70 1.96 5.22 2588.68 1985.78 11.70 1.85 4.93 2649.66 2010.43 12.70 1.76 4.67 2704.68 2029.04 13.70 t67 4.45 2754 67 2042.36 14.70 1.60 4.25 2800.22 2051.02 15.70 1.53 4.07 2841.82' 2055.52 16.70 1.47 3.91 2879.67 2056.29 17.70 1.42 3.76 2914.73 2053.68 18.70 1.37 3.63 2946.68 2048.01 1910 1.32 3.51 2975.97, 2039.53 20.70 1.26 3.40 3002.821 2028.48 21,70 1.24 3.30 3027.45 . 2015.05 22.70 1.20 3.20 3049.99 1999.43 23.70 1.17 3.11 3070.60 1981.76 24.70 1.14 3.03 3089.42 1962.19 25.70 1.11 2.95 3106.56 1940.84 26.70 1.08 2.88 3122.14 1917.82 27.70 1.06 2.81 3136.24 1893.24 28.70 1.03 2.75 ;3148,95 1867.18 29.70 1.01 2.69 3160.35 1839.73 30.70 0.99 2.63 3170.52 1810.97 31.70 0.97 2.53 3179.52 1780.95 32.70 0.95 2.53 3187.40 1749.75 33.70 0.93 2.48 3194.24 1717.43 34.70 0.91 2.43 3200.06 1684.04 35.70 0.90 2.39 3204.94 1649.62 36.70 0.88 2.34 320890 1614.23 37.70 0.87 2.30 3211.99 1577.91 38.70 0.85 2.26 3214.24 1540.70 39.70 0.84 2.23 3215.69 1502.63 40.70 0.82 2.19 3216.38 1463.74 41.70 0.81 2.16 3216.34 1424.07 42.70 0.80 2.12 3215.59 1383.64 43.70 0.79 2.09 3214,16 1342.47 44.70 0.77 2.06 3212.07 1300.61 45.70 0.76 2.03 3209.36 1258.08 46.70 0.75 2.00 3206.04 1214.89 47.70 0.74 1.98 3202.13 1171.07 48.70 0.73 1.95 3197.66 1126.64 49.70 0.72 1.92 3192.64 1081.63 50.70 0.71 190 3187.10 1036.05 51.70 0.71 1.88 3181.04 989.91 52.70 0.70 1.85 3174.48 943.25 53.70 0.69 t.83 3167.45 896.07 54.70 0.68 1.81 3159,95 848.38 55.70 0.67 1.79 3152.00' 800.21 56.70 0.66 1.77 3143.61 751.57 57.70 0.66 1.75 3134.80 702.47 MODIFIED RATIONAL METHOD LOT 18 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3.9 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 12.00 MIN 0.20 HR 2 0.95 0.36 0.6 5 1.46 0.52 0.64 PRE-DEV C= 0.22 10 1.82 0.64 0.65 25 2.18 0.78 0.64 STORM A= 0.64 50 2.66 0.92 0.66 B= 0.65 100 2.97 1.01 0.67 STORM INTENSITY= 1.82 IN/HR PRE-DEV Qp= 1.56 CFS POST-DEVELOPMENT BASIN AREA PRE= 3.9 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 7.80 CFS DELTA DURATION= 1 MAX VOLUME '"MAX VOLUME AVERAGEVOL! POND VOLUME CALCULATIONS: (CFT) (CFT} 3361.03 2110,40 Triangle Release 'Constant Release DURATION INTENSITY Qp POND VOLUME`=,POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 5.70 2.96 8.07 2210.95 1771.30 8058.96 6.70 2.66 7.26 2324.68 ., 1850.22 7.70 2.43 6.64 `2423,49 1913.59 8.70 2.25 6.13 2510.46 1964,62 9.70 2.09 5.71 2587.77 2005.55 10.70 1.96 5.36 2657.01 2038.03 11.70 1.85 5.06 2719.39` 2063.34 12.70 1.76 4.79 2775.66 2082.43 13.70 1.67 4.56 2827.16 .- 2096.11 14.70 1.60 4.36 `2873.91 2105.00 15.70 1.53 4.18 2916.60 2109.61 16,70 1.47 4.01 2955,66 2110.40 17.70 1.42 3.86 2991.43 2107.73 18.70 1.37 3 73 3024.22 2101.90 19.70 1.32 3.60 3054.29 2093.20 20.70 1.28 3.49 3081.85 2081.86 21.70 1.24 3.38 3107.12 2068.08 22.70 1.20 3.29 3130.25 2052.04 23.70 1.17 3.20 3151.41 2033.91 24.70 1.14 3.11 3170.72 2013.83 25.70 1.11 3.03 3188.32 1991.91 2610 1.08 2.96 3204.30 1968.29 27.70 1.06 2.89 3218.77 1943.06 28.70 1.03 2.82 3231.82 1916.32 29.70 1.01 2.76 3243.52 1888.15 30.70 0.99 2.70 3253.96 1858.62 31.70 0.97 2.65 3263.19 1827.82 32.70 0.95 2.59 3271.28 1795.80 33.70 0.93 2.54 3278.30 1762.63 34.70 0.91 2.49 3284.28 1728.36 35.70 0.90 2.45 3289.28 1693.04 36.70 0.88 2.40 3293.34 1656.71 37.70 0.87 2.36 3296.51 1619.44 38.70 0.85 2.32 3298.82 1581.24 39.70 0.84 2.29 3300.32 1542.17 40.70 0.82 2.25 3301.03 1502,26 41.70 0.81 2.21 3300.98 1461.54 42.70 0.80 2.18 3300.21 1420.05 43.70 0,79 2.15 3298.74 1377.80 44.70 0.77 2.12 3296.60 1334.84 45.70 0.76 2.09 3293.82 1291.18 46.70 035 2.06 3290.41 1246.86 47.70 0.74 2.03 3286.40 1201.89 48.70 0.73 2.00 3281.81 1156.29 49.70 0.72 1.97 3276.66 1110.09 50.70 0.71 1.95 3270.97 1063.31 51.70 0.71 1.92 3264.75 1015.96 52.70 0.70 1.90 3268.021 968.07 53.70 0.69 1.88 3250.80, 919,65 54.70 0.68 1.86 3243.11 870.71 55.70 0.67 1.83 ,3234 95 821.27 56.70 0.66 1.81 3226.34 771.35 57.70 0.66 1.79 3217.30 720.96 MODIFIED RATIONAL METHOD LOT 19 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 4.4 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 13.00 MIN 0.22 HR 2 0.90 0.36 0.6 5 1.38 0.52 0.64 PRE-DEV C= 0.22 10 1.73 0.64 0.65 25 2.08 0.78 0.64 STORM A= 0.64 50 2.52 0.92 0.66 B= 0.65 100 2.81 1.01 0.67 STORM INTENSITY= 1.73 IN/HR PRE-DEV Qp= 1.67 CFS POST-DEVELOPMENT BASIN AREA PRE= 4.4 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 8.81 CFS DELTA DURATION= 1 .MAX VOLUME "MAX VOLUME' '`AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) "'(CFT) 3855.23 Triangle'Release,i Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 5.70 2.96 9.10 2525.79,. 2049.00 9092.16 6.70 2.66 8.20 2656.78 2142.05 7.70 2.43 7.49 2770.94 2217.64 8.70 2.25 6.92 2871.75 2279.35 9.70 2.09 6.44 2961.65 2329.72 10.70 1.96 6.05 3042 45 2370.60 11.70 1.85 5.70 3115 51 2403.42 12.70 1.76 SA1 3181.90 ', 2429.27 13.70 1.67 5,15 3242.46 2449.03 14.70 1.60 4.92 3297.88 2463.41 15.70 1.53 4.71 -3348.73 2473.00 16.70 1.47 4.53 3395.48 2478.29 17.70 1.42 4.36 3438.52 2479.70 18.70 1.37 4,21 3478.19 2477.57 19.70 1.32 4.07 3514.80 2472.21 20.70 1.28 3.94 3548.58 2463.89 21.70 1.24 3.82 3579.76 2452.83 22.70 1.20 3.71 3608.'55 2439.24 23.70 1.17 3.61 3635.10 2423.30 24.70 1.14 3.51 3659.57 2405.17 25.70 1.11 3.42 3682.10 2384.99 26.70 1.08 3.34 3702.81 2362.89 27.70 1.06 3.26 _ 3721.82 2338,99 28.70 1.03 3.18 3739.22 2313.39 29.70 1.01 3.11 3755.11 2286.19 30.70 0.99 3,05 3769.57 2257.47 31.70 0.97 2.98 3782.67 2227.32 32.70 0.95 2.92 3794.48 ' 2195.80 33.70 0.93 2.87 3805.07 2162.99 34.70 0.91 2.81 3814.50 2128.95 35.70 0.90 2.76 3622.83 2093.73 36.70 0.88 2.71 3830.10 2057.40 37.70 0.87 2.67 3836.35 2019.98 38.70 0.85 2.62 3841.65 1981.55 39.70 0.84 2.58 3846.01 1942.13 40.70 0.82 254 3849.49 1901.76 41.70 0.81 2.50 3852.12 1860.49 42.70 0.80 2.46 3853.94 1618.35 43.70 0.79 2.42 3854.9fi - 1775.38 44.70 0.77 2.39 3855.23 1731.59 45.70 0.76 2.35 3854.77 1687.03 46.70 0.75 2.32 3853.61 1641.72 47.70 0.74 2.29 3851.77 1595.69 48.70 0.73 2.26 3849.27 1548.96 49.70 0.72 2.23 3646,14 1501.55 50.70 0.71 2.20 3842.40 1453.48 51.70 0.71 2,17 3838.07 1404.79 52.70 0.70 2.14 3833.16 1355.48 53.70 0.69 2.12 3827.70 1305.58 54.70 0.68 2.09 3821.70 1255.10 55.70 0.67 2.07 3815.18 1204.06 56.70 0.66 2.05 3808.15 `- 1152.48 57.70 0.66 2.02 3800.63, 1100.38 MODIFIED RATIONAL METHOD LOT 20 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 4.5 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A 8 PRE-DEV TC= 13.00 MIN 0.22 HR 2 0.90 0.36 0.6 5 1.38 0.52 0.64 PRE-DEV C= 0.22 10 1.73 0.64 0.65 25 2.08 0.78 0.64 STORM A= 0.64 50 2.52 0.92 0.66 B= 0.65 100 2.81 1.01 0.67 STORM INTENSITY= 1.73 IN/HR PRE-DEV Qp= 1.71 CFS POST-DEVELOPMENT BASIN AREA PRE= 4.5 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 9.01 CFS DELTA DURATION= 1 MAX VOLUME MAXVOLUME1 '`AVERAGEVOL° POND VOLUME CALCULATIONS: (CFT) (CFT) {CFT) 3942.85 2536:06 !-I",,--. Triangle Release`)Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 5.70 2.96 9.31 2583.19 2095.57 9298.80 6.70 2.66 8.38 2717.16, , 219013 7.70 2.43 7.66 2833.92 2268.04 8.70 2.25 7.07 2937.01 2331.15 9,70 2.09 6.59 '_3028.96::-.,,= 2382.66 10.70 1.96 6.18 3111759 2424A8 11.70 1.85 5.83 3186.31 - 2458.04 12.70 1.76 5.53 3254.21,. _.' 2484.48 13.70 1.67 5.27 '3316.15,' ''+ 2504.69 14.70 1.60 5.03 3372.83. 2519.40 15.70 1.53 4.82 3424.84 2529.21 16.70 1.47 4.63 3472.65 2534.62 17.70 1.42 4.46 3516.66 2536.0E 18.70 1.37 4.30 3557.24 2533.88 19.70 1.32 4.16 3594.68 2528.40 20.70 1.28 4.03 3629.23 2519.89 21.70 1.24 3,90 3661.12 2508.58 22.70 1.20 3.79 3690.56 2494.68 23.70 1,17 3.69 3717.71 2478.38 24.70 1.14 3,59 3742.74 2459.83 25.70 1.11 3.50 3765.78 2439.20 26.70 1.08 3.41 3786.97 2416.54 27.70 1.06 3.33 3806.41 2392.15 28.70 1.03 3.26 3824.21 2365.97 29.70 1.01 3.18 3840.45 2338.15 30.70 0.99 3.12 '3855.24 2308.78 31.70 0.97 3.05 3868.64 2277.94 32.70 0.95 2.99 3880.72 2245.71 33.70 0.93 2.93 3891.55 - 2212.15 34.70 0.91 2.88 3901.20 2177.34 35.70 0.90 2.83 3909.71 2141.32 2.77 3917.14 2104.15 36.70 0.8E 37.70 0,87 2.73 3923.54 2065.89 38.70 0.65 2,68 3928.96 2026.58 39.70 0.84 2.64 3933.42 1986.27 40,70 0.82 2.59 3936.98 1944.98 41.70 0.81 2.55 3939.67 1902.78 42.70 0.80 2.51 3941.53 1859.68 43.70 0.79 2.48 3942.57 1815.73 44.70 0.77 2,44 3942.85 1770.95 45.70 0.76 2,41 3942.38 1725.37 46.70 0.75 2.37 3941.19 1679.03 47.70 0.74 2,34 .3939.31 1631.95 48.70 0.73 2,31 3936.76 1584.16 49.70 0.72 2.28 3933.56 1535.67 50.70 0.71 2.25 3929.73 1486,52 51.70 0.71 2.22 3925.30 1436.72 52.70 0.70 2.19 3920.28, 1386.29 53.70 0.69 2.17 3914.70 1335.25 54.70 0.68 2,14 3908.56 1283.63 55.70 0.67 2.12 3901.89 1231.43 56.70 0.66 2.09 3894.70 1178.68 57.70 0.66 2.07 3887.01 _ 1125.38 5H 7n n RS 9 ne 497a 07 4n74 C7 MODIFIED RATIONAL METHOD LOT 21 Qp=CIA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3.5 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 13.00 MIN 0.22 HR 2 0.90 0.36 0.6 5 1.38 0.52 0.64 PRE-DEV C= 0.22 10 1.73 0.64 0.65 25 2.08 0.78 0.64 STORM A= 0.64 50 2.52 0.92 0.66 B= 0.65 100 2.81 1.01 0.67 STORM INTENSITY= 1.73 IN/HR PRE-DEV Qp= 1.33 CFS POST-DEVELOPMENT BASIN AREA PRE= 3.5 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 7.00 CFS DELTA DURATION= 1 MAXVOLUME `MAX VOLUME. ',AVERAGE VOL POND VOLUME CALCULATIONS: (CFT)'- 3066 66 1972. 9 2519 57; ? a.�>u. .. _.._. Triangle Release`,Constant Release DURATION INTENSITY Op POND VOLUME `POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) 4 (CFT) (CFT) 5.70 2.96 7.24 200915 1629.89 7232.40 6.70 2.66 6.52 2113.35 1703.90 7.70 2.43 5-96 2204.16 1764.03 8.70 2.25 6.50 2284.34 1813.12 9.70 2.09 5.13 2355.86 1853.18 10.70 1.96 4.81 242013 1885.71 11.70 1.85 4.54 2478.24 1911.81 12.70 1.76 4.30 2531.05 .: 1932.37 13.70 1.67 4.10 2579.23 1948.09 14.70 1.60 3.91 2623 31 1959.53 15.70 1.53 3.75 2663.76 1967.16 16.70 1.47 360 2700.95 ,,. 1971.37 17.70 1.42 3.47 2735.18 1972.49 18.70 1.37 3.35 2766.74 1970,79 19.70 1.32 3.23 2795.86 1966.53 20.70 1.28 3.13 2822.73 1959.91 21.70 1.24 3.04 2847.54 1951.12 22.70 1.20 2.95 2870.43 1940.31 23.70 1.17 2.87 2891.55 1927.63 24.70 1.14 2.79 2911.02 1913.20 25.70 1.11 2.72 2928.94 1897.15 26.70 1.08 2.65 2945.42 1879.57 27.70 1.06 2.59 2960.54 1860,56 28.70 1.03 2,53 2974.38 1840.20 29.70 1.01 2.48 2987.02 1818.56 30.70 0.99 2.42 2998.52 1795.71 31.70 0.97 2.37 3008.94 1771.73 32.70 0.95 2.33 3018.34 1746.66 33,70 0.93 2.28 3026.76 1720.56 34.70 0.91 2.24 3034.26 1693.48 35.70 0.90 2,20 3040.89" 1665.47 36.70 0.88 2.16 3046.67 1636.56 37.70 0.87 2.12 30511.64,j 1606.81 38.70 0.85 2.09 3055.85 1576.23 39.70 0.84 2.05 3059.33 1544.87 40.70 0.82 2.02 3062.10 1512.77 41.70 0.81 1.99 3064.19 1479.94 42.70 0.80 1.96 3065.63 1446.42 43.70 0.79 1.93 3066.45 . . 1412.23 44.70 0.77 1.90 3066.66 1377.40 45.70 0,76 1,87 3066.30 1341.96 46.70 0.75 1.85 3065.37 " 1305.92 47.70 0.74 1.82 3063.91 1269.30 48.70 0.73 1.80 3061.92 1232.12 49.70 0.72 1.77 3059.43 1194.41 50.70 0.71 1.75 3056.46 1156.18 51.70 0.71 1.73 3053.01 1117.45 52.70 0.70 1.71 3049.11 1078.22 53.70 0.69 1.69 3044 76 1038.53 54.70 0.68 1.67 3039.99 998.38 55.70 0.67 1,65 3034.80 957.78 56.70 0.66 1.63 3029.21 916.75 57.70 0.66 1.61 3023.23 875.30 MODIFIED RATIONAL METHOD LOT 22 Op=CiA PRE-DEVELOPMENT i=a'(DURATION)"-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 23.3 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 39.00 MIN 0.65 HR 2 0.47 0.36 0.6 5 0.69 0.52 0.64 PRE-DEV C= 0.22 10 0.85 0.64 0.65 25 1.03 0.78 0.64 STORM A= 0.64 50 1.22 0.92 0.66 B= 0.65 100 1.35 1.01 0.67 STORM INTENSITY= 0.85 IN/HR PRE-DEV Qp= 4.34 CFS POST-DEVELOPMENT BASIN AREA PRE= 23.3 ACRES POST-DEV TC= 17.00 MIN 0.28 HR POST-DEV C= 0.85 STORM INTENSITY= 1.45 IN/HR 10 YR POST-DEV Qp= 28.77 CFS DELTA DURATION= 1 MAX VOLUME, 'MAXV51JC1ME< ,AVERAGE,VOL POND VOLUME CALCULATIONS: (CFT) (CFT)„.,>> "�'(CFT) 41373.17 27181`12, "'34277,14 Triangle Release'Constant Release DURATION INTENSITY Op POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 16.15 1.50 29.75 24507.82; 20837.03 58464.36 17.15 1.44 28.61 24990.12 , 21214.84 18.15 1.39 27.57 25449.63_' i 21569.33 19.15 1.34 26.63 25888.37 21902.58 20.15 1.30 25.76 26308,12 22216.38 21.15 1.26 24.96 '26710.39 22512.29 22.15 1.22 24.22 27096 55: 22791.69 23.15 1.19 23.54 27467 76`. ? 23055.79 24.15 1.16 22.90 27625.09 `- 23305.64 25.15 1.13 22.31 28169.46 23542.22 26.15 1.10 21.75 28501.72 ` 23766.37 27.15 1.07 21.22 28622.62' 23978.88 28.15 1.05 20.73 29132.85 24180.42 29.15 1.02 20.26 29433.02 24371.65 30.15 1.00 19,83 29723.70 24553.13 31.15 0.98 19Al 30005.39 24725.38 32.15 0.96 19.01 30278.58, 24888.90 33.15 0.94 18.64 30543.70 25044.11 34.15 0,92 18.28 30801.13 25191_44 35.15 0.91 17.94 31051.26 25331.25 36.15 0.89 17.62 31294.41 25463.89 37.15 0.87 17.31 31530,91 25589.69 38.15 0.86 17.01 31761.05 25708.94 39.15 0.84 16.73 31985.10 25821.93 40.15 0.83 16.46 32203.32 25928.91 41.15 0.82 16.20 324i5.94 26030.14 42.15 0.81 15.95 32623.19 26125.82 43.15 0.79 15.70 32825.27 26216.19 44.15 0.78 15.47 33022.38 26301.45 45.15 0.77 15.25 33214.71 26381.77 46.15 0.76 15.03 33402,43 26457.34 47.15 0.75 14.82 33585.70 26528.33 48.15 034 14.62 33764.68 26594.69 49.15 033 14,43 33939.51, 26657.17 50.15 0,72 14.24 34110.33 26715.33 51.15 0.71 14.06 34277.28 26769.48 52.15 0.70 13,88 34440.47 26819.76 53.15 0.69 13,71 34600.03 26866.29 54.15 0.68 13.55 34756.07 26909.19 55.15 0.68 13.39 34908.69' 26948.56 56.15 0.67 13,23 35057.99 26984.51 57.15 0.66 13.08 35204.08 27017.13 58.15 0.65 12.94 35347.04 27046.53 59.15 0.65 12.79 35486,97 27072.79 60.15 0.64 12.65 35623.95 27096.01 61.15 0.63 1252 35758 05 27116.25 62.15 0.63 12.39 35889.36 27133.60 63.15 0.62 12,26 36017,94 27148.15 64.15 0.61 12.14 36143.88 27159.95 65.15 0.61 12.01 36267.23 27169.08 66.15 0.60 11.90 36388.67 27175.61 67.15 0.59 11.78 36506.45` 27179.61 68.15 0.59 11.67 36622.43 27181.12 69.15 0.58 11.56 36736.08 27180.22 MODIFIED RATIONAL METHOD LOT 23 Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)"-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 3.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 13.00 MIN 0.22 HR 2 0.90 0.36 0.6 5 1.38 0.52 0.64 PRE-DEV C= 0.22 10 1.73 0.64 0.65 25 2.08 0.78 0.64 STORM A= 0.64 50 2.52 0.92 0.66 B= 0.65 100 2.81 1.01 0.67 STORM INTENSITY= 1.73 IN/HR PRE-DEV Qp= 1.22 CFS POST-DEVELOPMENT BASIN AREA PRE= 3.2 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.7 STORM INTENSITY= 2.86 INIHR 10 YR POST-DEV Qp= 6.40 CFS DELTA DURATION= 1 MAX VOLUME ;'MAX VOLUME° AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (CFT) (CFt) 2803 80 1803 42 2303.6.1_ _. Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME a POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 5.70 2.96 6.62 1836 94 1490.18 6612.48 6.70 2.66 5.96 1932.21 1557.85 7.70 2.43 5.45 2015 23 �� 1612.83 8.70 2.25 5.03 2088 54 1657.71 9.70 2.09 4.69 2153.93 -.,_' 1694.34 10.70 1.96 4.40 2212 69 1724.07 11.70 1.85 4.15 2265 82 1747.94 12.70 1.76 3.93 231411 1766.74 13.70 1.67 3.74 235815 1781.11 14.70 1.60 3.58 2398.46 1791.57 15.70 1.53 3.43 2435 44 .` 1798,55 16.70 1.47 3,29 2469.44 1802.40 17.70 1.42 3.17 2500.74 1803.42 18.70 1.37 3,06 2529.59 1801.87 1970. 1.32 2.96 2556.22 1797.97 20.70 1.28 2.86 2580.78 1791.92 21.70 1.24 2.78 2603.46 ', 1783.88 22.70 1.20 2,70 2624.40 1773.99 23.70 1.17 2.62 2643.71" ? 1762.40 24.70 1.14 2,55 2661.50 ' 1749.21 25.70 1.11 2.49 2677.89 1734.54 26.70 1.08 2.43 2692.96 1718.47 27.70 1.06 237 2706,78 1701.08 28.70 1.03 2.32 2719.44 1682.47 29.70 1.01 2.26 2736.99 '. 1662.68 30.70 0.99 2.22 2741.50 " 1641.80 31.70 0.97 2.17 2751 03 1619.87 32.70 0.95 2.13 275962 _=, 1596.95 33.70 0.93 2.09 2767.33 ., 1573.09 34.70 0.91 2.05 2774.19 1548.33 35.70 0.90 2,01 278024 152212 36.70 0.88 1.97 2785.52 1496.29 37.70 0.87 1.94 2790.08 1469.08 38.70 0.85 1.91 2793.92 1441.13 39.70 0.84 1.88 279710 1412.46 40.70 0.82 1.84 2799.63 1383.10 41.70 0.81 1.82 280154 1353.09 42.70 0.80 1.79 2802.86 1322.44 43.70 0.79 1.76 2803.61 1291.18 44.70 0.77 1.74 2803.80 1259.34 45.70 0.76 1.71 2803.47 1226.93 46.70 0.75 1.69 2862.62 1193.98 47.70 0.74 1.66 2801.29 1160.50 48,70 0.73 1,64 2799.47 1126.51 49.70 0.72 1.62 2797.20 1092.03 50.70 0.71 1.60 2794.47 1057.08 51.70 0.71 1.58 2791.32. ! 1021.67 52.70 0.70 1.56 2787.76 985.80 53.70 0.69 1.54 2783.78 949.51 54.70 0.68 1.52 2779.42 912.80 55.70 0.67 1.50 2774.68 875.68 56.70 0.66 1.49 2769.56 838.17 57.70 0.66 1A7 2764.04 800.27 MODIFIED RATIONAL METHOD LOT 24 Qp=CiA PRE-DEVELOPMENT i=a.(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.5 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 12.00 MIN 0.20 HR 2 0.95 0.36 0.6 5 1.46 0.52 0.64 PRE-DEV C= 0.22 10 1.82 0.64 0.65 25 2.18 0.78 0.64 STORM A= 0.64 50 2.66 0.92 0.66 B= 0.65 100 2.97 1.01 0.67 STORM INTENSITY= 1.62 IN/HR PRE-DEV Qp= 0.60 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.5 ACRES POST-DEV TC= 6.00 MIN 0.10 HR POST-DEV C= 0.75 STORM INTENSITY= 2.86 IN/HR 10 YR POST-DEV Qp= 3.22 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME' ,AVERAGE VOC POND VOLUME CALCULATIONS: ,,(CFT), (CFT) (CFT) , . 1423.95 '91,7 Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME'{POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) „(CFT) (CFT) (CFT) 5.70 2.96 3.33 '926.18 ` 754.29 3321.00 6.70 2.66 2.99 974.34 788.74 7.70 2.43 2.73 1016.34 816.83 8.70 2.25 2.53 105147 839.85 9.70 2.09 2.35 1086.62 858.73 10.70 1.96 2.21 1116.44 874.16 11.70 1.85 2.08 ,11,43 43 886.64 12.70 1.76 1.98 1167,99 896.58 13.70 1.67 1.88 1190.42 904.30 14.70 1.60 1.80 1210.97 910.06 15.70 1.53 1.72 1229.85 914.07 16.70 1.47 1.65 1247.24 916.52 17.70 1.42 1.59 1263.27. 917.54 18.70 1.37 1.54 1278.07 917.28 19.70 1.32 1A9 1291.74 915.84 20.70 1.28 1.44 1304.39 913.32 21.70 1.24 1.39 1316.09 909.60 22.70 1.20 1.35 1326.91 905.35 23.70 1.17 1.32 1336.92 900.06 24.70 1.14 128 1346.17 893.96 25.70 1.11 1.25 1354.71 887.11 26.70 1.08 1.22 1362.58 879.57 27.70 1.06 1.19 1369.83 871.36 28.70 1.03 1.16 1376.50 862.54 29.70 1.01 1.14 1382.61 853.14 30.70 0.99 1.11 1388.20 843.18 31.70 0.97 1.09 1393.29 832.70 32.70 0.95 1.07 1397.91 821.72 33.70 0.93 1.05 1402.09 810.27 34.70 0.91 1.03 '1405.84 798.37 35.70 0.90 1.01 1409.19 786.04 36.70 0.88 0.99 1412.16 773.31 37.70 0.87 0.97 1414.75 760.18 38.70 0.85 0.96 1416.99 746.68 39.70 0.84 0.94 '1418.90 732.82 40.70 0.82 0.93 1420.48 718.61 41.70 0.81 0.91 1421.75 704.08 42.70 0.80 0.90 "1422.72 689.23 43.70 0.79 0.88 1423.40 674.07 44.70 0.77 0.87 1423.81 658.62 45.70 0.76 0.86 1423.95 642.89 46.70 0.75 0.85 1423.83 626.88 47.70 0.74 0.84 1423.47 610.61 48.70 0.73 0.82 1422.86 594.09 49.70 0.72 0.81 1422.03 577.31 50.70 0.71 0.80 1420.97 560.30 51.70 0.71 0.79 1419.70 543.06 52.70 0.70 0.78 1418.22 525.60 53.70 0.69 0.77 1416.53 507.92 54.70 0.68 0.76 1414.65 490.03 55.70 0.67 0.76 1412.57 471.93 56.70 0.66 0.75 1410.31 453.64 57.70 0.66 0.74 1407.87 435.16 58.70 0.65 0.73 1405.26 416.49 MODIFIED RATIONAL METHOD LOT 25 Qp=CIA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1.2 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A 8 PRE-DEV TC= 10.00 MIN 0.17 HR 2 1.05 0.36 0.6 5 1.64 0.52 0.64 PRE-DEV C= 0.22 10 2.05 0.64 0.65 25 2.46 0.78 0,64 STORM A= 0.64 50 3.00 0.92 0.66 B= 0.65 100 3.35 1.01 0.67 STORM INTENSITY= 2.05 IN/HR PRE-DEV Qp= 0.54 CFS POST-DEVELOPMENT BASIN AREA PRE= 1.2 ACRES POST-DEV TC= 4.30 MIN 0.07 HR POST-DEV C= 0.75 STORM INTENSITY= 3.55 IN/HR 10 YR POST•DEV Qp= 3.19 CFS DELTA DURATION= 1 .. ._ MAX VOLUME`,-;MAX VOLUME , ` AVERAGE VOL POND VOLUME CALCULATIONS: (CFT} (CFT) �;_ (CFT) 1080 11 702 71 . " Triangle Release'Constant Release DURATION INTENSITY Op POND VOLUME' POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) � (CFT) (CFT) 4.09 3.67 3.30 673.43 560.12 2656.80 5.09 3.18 2.87 -`72167 595.62 6.09 2.83 2.55 762.12 - 623.09 7.09 2,57 2.31 796.79 644.60 8.09 2.35 2.12 826 97 661.48 9.09 2.18 1,96 85356 - 674.63 10.09 2.04 1.84 87716 684.71 11.09 1.92 1.73 89631 :;',^ 692.21 12.09 1.81 1.63 917.31 697.49 13.09 1.72 1.55 934 46 700.85 14.09 1.64 1.48 949.99 702.53 15.09 1.57 1.41 964.06, 702.71 16.09 1.51 1.36 976.89,, 701.56 17.09 1.45 1.30 988.55,,;,.' 699.21 18.09 1.40 1.26 999.17 695.77 19.09 1.35 1.21 1008.64 691.34 20.09 1.30 1.17 1017.65 686.01 21.09 1.26 1.14 1025.65 679.83 22.09 1.23 1.10 1032.92, ; 672.89 23.09 1.19 L07 1039.50 665.24 24.09 1.16 1.04 1045.45 656.92 25.09 1.13 1.02 1050.81 647.98 26.09 1,10 0.99 1056.62 638.45 27.09 1.07 0.97 1059.91. 628.39 28.09 1.05 0.94 1063.71",:" 617.82 29.09 1.02 0 92 1067.05 606.76 30.09 1.00 0.90 1069.96 ' 595.25 31.09 0.98 0.88 1072.46 ;;;,:., 583,30 32.09 0.96 0.87 1074.57 570.95 33.09 0.94 0.85 1076.32 558.21 34.09 0.92 0.83 1077.71 545.11 35.09 0.91 0.82 1078.77 531.65 36.09 0.89 0.80 1079.52 517.86 37.09 0.87 0,79 1079.96' 503.74 38.09 0.86 0.77 1080.11 489.32 39.09 0.85 0.76 1079.98 474.61 40.09 0.83 0.75 1079.59 459.62 41.09 0.82 0.74 1078.94 444.36 42.09 0.81 0.73 1078.04 426.84 43.09 0.79 0,71 1076.92 413.07 44.09 0.78 0.70 1075.56 397.06 45.09 0.77 0.69 1073.99 380.82 46.09 0.76 0.68 1072.21 364.36 47.09 0.75 0,67 1070.22_: 347.69 48.09 0.74 0,67 1068.04 330.81 49.09 0.73 0.66 1065.67, 313.72 50.09 0.72 0.65 1063.12 296.45 51.09 0.71 0.64 1060.39` 278.98 52.09 0.70 0.63 1057.49 261.34 53.09 0.69 0.62 1054.42` 243.52 54.09 0.68 0.62 1051.20 225.53 55.09 0.68 0.61 1047.82 207.38 56.09 0.67 0-60 1044.28 189.06 MODIFIED RATIONAL METHOD LOT 26 Op=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 9.00 MIN 0.15 HR 2 1.12 0.36 0.6 5 1.75 0.52 0.64 PRE-DEV C= 0.22 10 2.20 0.64 0.65 25 2.63 0.78 0.64 STORM A= 0.64 50 3.22 0.92 0.66 B= 0.65 100 3.60 1.01 0.67 STORM INTENSITY= 2.20 IN/HR PRE-DEV Op= 0.48 CFS POST-DEVELOPMENT BASIN AREA PRE= 1 ACRES POST-DEV TC= 4.00 MIN 0.07 HR POST-DEV C= 0.75 STORM INTENSITY= 3.72 IN/HR 10 YR POST-DEV Op= 2.79 CFS DELTA DURATION= 1 MAX VOLUME 'MAX VO!UME' AVERAGE"VOL': POND VOLUME CALCULATIONS: (CFT) '(CFT} (CFT) T, `86¢.58 ,561.96 = 71377,�� Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME 'POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT)` (CFT) (CFT) 3.80 3.85 2.89 544 76 , 451.11 2214.00 4.80 3.31 2.48 586.31 481.35 5.80 2.92 2.19 620.70 504.20 6.80 2.64 1.98 649 87 521.66 7.80 2.41 1.81 675,05 534.98 8.80 2.23 1.67 697 04 545.01 9.80 2.08 1.56 716 42 552.32 10.80 1.95 1.46 733,63 557.38 11.80 1.84 1.38 748 98 560.50 12.80 1.75 1.31 '.762 73 561.96 13.80 1.66 1.25 775 0$ 561.95 14.80 1.59 1.19 788.19 560.66 15.80 1.52 1.14 .798 20 �z �' 558,21 16.80 1.46 1.10 805.22 554.73 17.60 1.41 1.06 813.35 550.32 18.80 1.36 1.02 820.67 545.06 19.80 1.32 0.99 827.24 539.02 20.80 1.27 0.96 833.14 532.26 21.80 1.24 0.93 838.46 524.85 22.80 1.20 0.90 843.09 516.83 23.80 1.17 0.88 847.23 508.24 24.80 1.14 0,85 850.88 499.12 25.80 1.11 0"83 854.05 489.51 26.80 1.08 0.81 856 79 479.44 27.80 1.06 0.79 859.11 468.93 28.80 1.03 0.77 86104 458.01 29.80 1.01 0.76 862.61 446.70 30.80 0.99 0.74 863.83 435.03 31.80 0.97 0.73 864.72 423.02 32.80 0.95 0.71 865.30 410.67 33.80 0.93 0.70 865M 398.01 34.80 0.91 0.68 865.58 385.06 35,80 0.90 0.67 865.32 371.82 36.80 0.88 0.66 864.80 358.31 37.80 0.86 0.65 864.03. 344.54 38.80 0.85 0.64 863.03 330.52 39.80 0.84 0.63 861.80 316.26 40.80 0.82 0.62 860.36 301.78 41.80 0.81 0.61 858,72 287.08 42.80 0.80 0,60 856.87 272.17 43.80 0.79 0.59 854.84 257.05 44.80 0.77 0.58 852.62 241.74 45.80 0.76 0.57 850.22 . 226.25 46.80 0.75 0.56 647.65 . 210.57 47.80 0.74 0.56 844.92 194.72 48.80 0.73 0.55 842.03 178.69 49.80 0.72 0.54 838.99 162.51 50.80 0.71 0.53 835.80 146.16 51.80 0.70 0.53 832.46 129.67 52.80 0.70 0.52 -828.99 113.02 53,80 0.69 0.52 825.38 9624 54.80 0.68 0.51 821.64 79.31 55.80 0.67 0.50 '817.77 62.25 56,80 0.66 0.50 813.78 45.05 MODIFIED RATIONAL METHOD LOT 27 Qp=CIA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 5.2 ACRES STORM EVENT NTENSIT STORM 1 COEFF (YR) (IN/HR) A B PRE-DEV TC= 13.00 MIN 0.22 HR 2 0.90 0.36 0.6 5 1.38 0.52 0.64 PRE-DEV C= 0.22 10 1.73 0.64 0.65 25 2.08 0.78 0.64 STORM A= 0.64 50 2.52 0,92 0.66 B= 0.65 100 2.81 1.01 0.67 STORM INTENSITY= 1.73 IN/HR PRE-DEV Qp= 1.98 CFS POST-DEVELOPMENT BASIN AREA PRE= 5.2 ACRES POST-DEV TC= 7.30 MIN 0.12 HR POST-DEV C= 0.85 STORM INTENSITY= 2.52 IN/HR 10 YR POST-DEV Qp= 11.12 CFS DELTA DURATION= 1 MAX VOLUME "MAX VOLUME, 'AVERAGE VOL 1 POND VOLUME CALCULATIONS: '(CFT)", (CFT) •< (CFT) '6189 04 4006 37 5096 71 Triangle Release. Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) ; (CFT) (CFT) 6.94 2.60 11.50 3940.47,". 3244.63 13047.84 7.94 2.38 10.54 '4112.13 3370.57 8.94 2.21 9.75 4265.56 ;_ 3477.70 9.94 2.06 9.10 4404.01 3569.35 10.94 1.94 8.55 4529.92' 3648.01 11.94 1.83 8.08 464511 3715.58 12.94 1.74 7.67 4751 04 3773.54 13.94 1.65 7.31 4848 85 3823.09 14.94 1.58 6.99 4939.50 3865.19 15.94 1.52 6.70 �,50,23 76," 3900.64 16.94 1.46 6A4 5102.25 .'^ 3930.12 17.94 1.40 6.20 5175.56 3954.20 18.94 1.35 5.99 5244.115 3973.35 19.94 1.31 5.79 5308.41 _, 3988.01 20.94 127 5.61 5368.71 3998.52 21.94 1.23 5,44 5425.35 4005.22 22.94 1.20 5.29 5478.59 4008.37 23.94 1.16 5.14 -5528.70 4008.25 24.94 1.13 5.01 5575.86 . 4005.05 25.94 1.10 4.88 5620.29 3998.99 26.94 1.08 4.76 5662.15 3990.23 27.94 1.05 4.65 5701.59 3978.96 28.94 1.03 4.54 5736.716 3965.30 29.94 1.01 4.45 5773.78 3949.39 30.94 0.98 4.35 5866.78 3931.36 31.94 0.96 4.26 5837.85 3911.31 32.94 0.95 4.18 5867.11 3889.36 33.94 0.93 4.10 5894.63 3865.58 34.94 0.91 4.02 5920.50 3840.07 35.94 0.89 3.95 5944.80 3812.91 36.94 0.88 3.88 5967.61 3784.18 37.94 0.86 3.81 5968,W 3753.94 38.94 0.85 3.75 6008.97 3722.25 39.94 0.83 3.69 6027.65 3689.18 40.94 0.82 3.63 6045.08 3654.79 41.94 0,81 3.57 6061.29 3619.12 42.94 0.80 3.52 6076.34 3582.23 43.94 0.78 3,46 6090,27 3544.16 44.94 0.77 3.41 616113 3504.95 45.94 0.76 3.37 6114.95 3464.65 46.94 0.75 3.32 6125.77 3423.30 47.94 0.74 3.27 6135.62 3380.93 48.94 0.73 3.23 6144.54 3337.57 49.94 0.72 3.19 6152.56 3293.26 50.94 0.71 3,15 6159.71 3248.03 51.94 0.70 3.11 6166,02 3201.91 52.94 0.69 3,07 6171.50 3154.93 53.94 0.69 3.03 6176.20 3107.11 54.94 0.68 3.00 6180.13 3058.48 55.94 0.67 2.96 6163.32 3009.06 56.94 0.66 2.93 6185.78 2958.87 ? 57.94 0.65 2.89 6187.54 2907.94 58.94 0.65 2.86 6188.62 2856.30 5Q Qd n Re �c1 Now n ' 1- EAST & WEST CATRON STREAM FLOWS The Gallatin Center Subdivision Phase 1 MODIFIED RATIONAL METHOD EAST CATRON @ BAXTER LANE Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ `1357 ACRES STORM EVENT NTENSIT ,I 'STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 0.00 MIN 0.00 HR 2 ERR 0.36 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR 0.64 r 0.65 Q ERR 0.78 0.64 STORM A= 0.78 50 ERR 0.92 0.66 B=;, 0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1357 ACRES POST-DEV TC= 161.40 MIN 2.69 HR POST-DEV C= 0.4365 STORM INTENSITY= 0.41 IN/HR 10 YR POST-DEV Op= 245.25 CFS DELTA DURATION= 1 MAX yOLUME '>MAX VOCIJMEfs AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (CFTj (CFT} :1 ERR ERR ERR J Triangle Rplease'l Constant Release DURATION INTENSITY Op POND,VOLUME'S POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 153.33 0.43 253.44 ERR ERR 1748559.64 154.33 0.43 252.39 ERR, ERR 155.33 0.42 251.35 ERR ERR 156.33 0.42 250.32 ERR ERR 157.33 0.42 249.30 ERR ERR 158.33 0.42 248.29 ERR ERR 159.33 0.42 247.29 ERR = ERR 160.33 0.42 246.30 ""ERR ERR 161.33 0.41 245.32 ERR k ERR 162.33 0.41 244.35 ERR ,`'( ERR 163.33 0.41 243.40 ERR 164.33 0.41 242.45 ERR ERR 165.33 0.41 241.51 'ERR ERR 166.33 0,41 240.58 ERR ERR 167.33 0.40 239.66 ERR,",:: ERR 168.33 0.40 238.74 ERR ERR 169.33 0.40 237.84 ERR ERR 170.33 0.40 236.95 ERR ERR 171.33 0.40 236.06 ERR ERR 172.33 0.40 235.18 :ERR ERR 173.33 0.40 234.31 ERR ERR 174.33 0.39 233.45 ERR_. ERR 175.33 0.39 232.60 ERR ERR 176.33 0.39 231.75 ERR ERR 177.33 0.39 230.92 ERR ERR 178.33 0.39 230.09 ERR ERR 179,33 0.39 229,26 ERR ERR 180.33 0.39 228.45 ERR ERR 181.33 0.38 227.64 ERR ERR 182.33 0.38 226.84 ERR ERR 183.33 0.38 226.05 ERR -; ERR 184.33 0.38 225.27 ERR '; ERR 185.33 0.38 224,49 ERR ERR 186.33 0,38 223.71 ERR ERR 187.33 0.38 222.95 ERR '. ERR 188.33 0.38 222.19 ERR ERR 189.33 0.37 221.44 ERR ERR 190.33 0.37 220.69 <ERR ERR 191.33 0.37 219.96 ERR ERR 192.33 0.37 219.22 ERR ERR 193.33 0.37 218.50 ERR ERR 194.33 0.37 217.78 ERR `- # ERR 195.33 0.37 217.06 .:ERR_,,..j ERR 196.33 0,37 216.35 ERR ERR 197.33 0.36 215.65 ERR',' ;1',:€ ERR 198.33 0.36 214.95 ERR ERR 199.33 0.36 214.26 ERR ERR 200.33 0.36 213.58 ;:ERR -) ERR - 201.33 0.36 212.90 ERR k ERR 202.33 0.36 212.23 ;ERR ERR 203.33 0.36 211.56 , ;.ERR }a ERR 204.33 0.36 210.89 ;ERR �. ERR 205.33 0.35 210,24 ERR ERR 206.33 0.35 209.58 ;ERR �, ERR MODIFIED RATIONAL METHOD EAST CATRON @ SEITZ ST. Op=CIA PRE-DEVELOPMENT I=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ `.,.,1366 ACRES STORM EVENT NTENSIT :'STORM i COEFF (YR) (IN/HR) `;A B 'RE-DEV TC= 0.00 MIN 0.00 HR 2 ERR 0.36 .: .:.; 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR 0.64 0.65 Q,5.; ERR 0.78 0.64 STORM A='- ;0.78 50 ERR 0.92 .. ..0.66 B= 0.64 100 ERR .1.01 [,0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1366 ACRES POST-DEV TC= 164.40 MIN 2.74 HR POST-DEV C= 0.44 STORM INTENSITY= 0.41 IN/HR 10 YR POST-DEV Op= 245.94 CFS DELTA DURATION= 1 MAX VOLUh1E'MMAX VOLUME, (-HVERAGE VOt: POND VOLUME CALCULATIONS: (CFT) r�+drg ;(CFT) ERR _ ERft Triangle Release']Constant Release DURATION INTENSITY Op POND VOLUME,,POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 156.18 0.42 254.15 ERR„ ERR 1774270.08 157.18 0.42 253.12 ERR ,7 ERR 158,18 0.42 252.09 ERR ., ,:? ERR 159.18 0.42 251.C8 ERR ! ERR j •,, 160.16 0.42 250.07 ERR ; "s ERR 161.18 0.41 249.08 ERR ?',z ERR 162.18 0.41 248.C9 ERR 163.18 0.41 247.12 ERR f ERR 164.18 0.41 245.16 ERR ERR 165.18 0.41 245.20 ERR $ ERR 166.18 0.41 244.26 ERR ERR 167.18 0.40 243.32 ERR ERR 163.18 CAO 242.39 -ERR -i ERR 169.18 0.40 241.47 ERR ' ERR 170.18 0.40 240.57 ERR , ERR 171.18 0.40 239.67 ERR k, ERR 172.18 0A0 238.77 ERR ERR 173.18 0.40 237.69 ERR '•'''• ERR 174.18 0.39 237.02 ERR ERR 175.18 0.39 236.15 ERR ERR 176.18 0.39 235.29 ERR ERR 177.18 0.39 234.44 ERR ERR 178.18 0.39 233.60 ERR.7_ 's ERR 179.18 0.39 232.76 ERR ERR 180.18 0.39 231.93 ERR ERR 181.18 0.38 231.11 ERR ERR 182.18 0.38 230.30 ERR;:'.,; ERR 183.18 0.38 229.49 ERR ' ERR 184.18 0.38 228.70 ERR ERR 185.18 0.38 227.91 ERR a ERR 186.18 0.38 227.12 ERR ERR 157.13 0.38 226.34 ERR ERR 138.13 0.33 225.57 ERR ERR 189.18 0.37 224.81 ERR ERR 190.18 0.37 224.05 ERR ERR 191.18 0.37 223.30 ERR ERR 192.18 0.37 222.56 ERR r .'1 ERR 193.18 0.37 221.82 ERRS ERR 194.18 0.37 221.09 ERR ERR 195.18 0.37 220.36 ERR ! ERR 196.18 0.37 219.64 ERR t'1 ERR 197.18 0.36 218.93 ERR ' '.? ERR 19318 0.36 218.22 ERR - ERR 199.13 0.36 217.52 ERR 1 ERR 200.13 0.36 216.82 ERR_ ERR 201.18 0.36 216.13 ERR ERR 202.18 0.36 215.45 ERR+a ERR > 203.18 0.36 214.77 ERR"' ERR 204.18 0.36 214.09 ERR # + ERR 205.18 0.36 213.43 ERR ERR 206.16 0.35 212.76 ERR ERR 207.18 0.35 212.11 ERR ERR 208.18 0.35 211.45 ERRt. j ERR MODIFIED RATIONAL METHOD EAST CATRON @ DEADMAN'S GULCH Qp=CiA PRE-DEVELOPMENT I=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1422 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A 0 °RE-DEV TC= 0.00 MIN 0.00 HR 2 ERR '0.36 0.6 5 ERR 0.52 .',: 0.64 PRE-DEV C= 0.2 10 ERR 0.64 0.65 (.25j ERR 0.78 0.64 STORM A= . 0.78 50 ERR 0.92 0.66 B- '`0.64 100 ERR 1.0.1 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1422 ACRES POST-DEV TC= '}`175.00 MIN 2.92 HR POST-DEV C= 0.45 STORM INTENSITY= 0.39 IN/HR 10 YR POST-DEV Qp= 251.58 CFS DELTA DURATION= 1 MAX VOLUh1E MAX VOLUME" "AVERAGE VOL POND VOLUME CALCULATIONS: ,(CFT) ` "r s +<(CFT) `a (CFT)a 3# ,ERR may_ EFtR ;„ ERRr# x,a< ,Triarigte Release:(Constant Release DURATION INTENSITY Op `POND VOLOME4,POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) 166.25 0.41 259.98 ERRz" ',' ! ERR 1888984.80 167.25 0.40 258.99 �:^ERR -- ERR 168.25 0.40 258.00 ERR ti`-"� ERR 169.25 0.40 257.02 - ERR a ERR 170.25 0.40 256.05 ERR ERR 171.25 0.40 255.09 ERR ERR 172.25 0.40 254.15 r ',, ERR s >' ~ i ERR �,_•y 173.25 0.40 253.21 _ERR � ERR 174.25 0.39 252.27 ERR ;^,r. ERR 175.25 0.39 251.35 " EPR "^_ c ERR 176.25 0.39 250.44 ERR r , ERR 177.25 0.39 249.53 ERR*. ''r ' ERR 178.25 0.39 248.64 ERR } ERR 179.25 0.39 247.75 ` ERR ERR 180.25 0.39 246.87 ERR ERR 181.25 0.33 2.15 99 EPR ERR 182.25 0.38 245.13 ERR ERR 183.25 0.38 244.27 EPR ERR 184.25 0.38 243.42 ERR ERR 185.25 0.38 242.53 ERR ERR 186.25 0.38 241.75 _ ERR < ERR 187.25 0.38 24C.92 ERR 'sr ERR 183.25 0.38 240.10 ERR ERR 129.25 0.37 239.29 ERR ' ERR 190.25 0.37 238.48 ERR 5: ERR 191,25 0.37 237.68 ERR _:'• { ERR 192.25 0.37 236.89 ERR 3- ERR 193.25 0.37 236.11 ERR ERR 194.25 0.37 235.33 ERR ., .' ERR - 195.25 0.37 234.56 ERRS ERR 196.25 0.37 233.79 ERR ERR 197.25 0.36 233.03 ERR { ERR 198.25 0.36 232.28 ERR z'^'•',! ERR 199.25 0.36 231.53 ERR '„ ERR 200.25 0.36 230.79 ERR ". ERR 201.25 0.36 230.06 ERR ERR 202.25 0.36 229.33 ERR ''•r" ,>`'i ERR 203.25 0.36 228.60 ERR i ERR 204.25 0.36 227.89 ERR 7ij ERR 205.25 0.36 227.18 ERR .,f ERR 206.25 0.35 22647 ERR ,', ERR 207.25 0.35 225.77 ERR R ERR 208.25 0.35 225.08 ERR, :, ERR 209.25 0.35 224.39 ERR %n;'',;` ERR 210.25 0.35 223.70 ERR ERR 211.25 0.35 223.03 ERR . ERR 212.25 0.35 222.35 ERR ? ,' ERR 213.25 0.35 221.68 ERR " r', ERR >; 114.25 0.35 221.02 ERR u:,,:3 ERR 215.25 0.34 220.36 ERR s;i ERR 216.25 0.34 219.71 ERR ERR 217.25 0,34 219.06 ERR : . _ ERR 218.25 0.34 21842 ERR_ fix? ERR 219,25 0.34 217.78 :ERRi .;', ERR _ MODIFIED RATIONAL METHOD EAST CATRON @ BURKE ST. Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)'-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1487 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) ''A B PRE-DEV TC= 0.00 MIN 0.00 HR 2 ERR ''0.36 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR ...0.64 0.65 ERR .0.78 0.64 STORM A= 0.78 50 ERR 0.92 0.66 B= " '0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1487 ACRES POST-DEV TC= 181.80 MIN 3.03 HR POST-DEV C= 0.46 STORM INTENSITY= 0.38 IN/HR 10 YR POST-DEV Op= 262.45 CFS DELTA DURATION= 1 MAX VOLUME 1MAX.V6LUME 1 �AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (CfT} { (CFT) { ERR s ",>.xERR ,^ �' s ;Triangle Release:j Constant Release DURATION INTENSITY Op POND VOLUME;=POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT)- £ (CFT) (CFT) r 172.71 0.40 271.20 J ERR '` ERR 2019227.04 173.71 0.40 270.20 ERRns ERR 174.71 0.39 269,21 ERR ' ERR 175.71 0.39 268.23 ERR '` ERR :` 176.71 0.39 267.26 ERR�.; ,': ERR 177.71 0.39 265.30 ERR y it ^1 ERR 173.71 0.39 265.34 z ERR ,F $ ERR 179.71 0.39 264,40 ERR ;_$ ERR 180.71 0.39 263.46 ERR?s ERR 131.71 0.38 252.53 ERR ERR 182.71 0.38 261.61 ERR w+ ERR 183.71 0.39 260.70 ERR s`- ERR 184.71 0.38 259.79 ERR ERR 185.71 0.38 258.90 ERR ; ERR 185.71 0.33 258,01 ERR ERR te7.71 0.38 257.13 ERR,y ERR 133.71 0.37 25625 - ERR :' ERR 189.71 0.37 255.39 ERR ERR 190.71 0.37 254.53 ERR `'. ERR 191.71 0.37 253.63 'ERR",."', ERR 192.71 0.37 252 84 ERR ; ERR 193.71 0.37 252.00 ERR ERR 194.71 0.37 251.17 ERR*r ERR 195,71 0.37 250.35 ERR :' ERR 196.71 0.36 249.53 ERR - ERR 197.71 0.36 248.73 ERR, ERR 198.71 0.36 247.92 ERR ;? ERR 199.71 0.36 247.13 ERR,;! ERR 200.71 0,36 246.34 ERR j. :'< ERR 201.71 0.36 245.56 ERR ERR 202.71 0.35 244.78 7 ERR ERR 203.71 0.36 244.01 ERR ERR 204.71 0.36 243.25 ERR' ERR 205.71 0.35 242.49 ERR ERR 206.71 0.35 241.74 ERR;, ERR 207.71 0.35 240.99 ERR.; ERR 208.71 0.35 240.26 ERR, ERR 209.71 0.35 239.52 ERR ERR 210.71 0.35 23879 ERR'i ERR 217.71 0.35 238.07 ERR.' ERR 212.71 0.35 237.35 ERR'; ERR 213.71 0.35 236.64 ERR ERR 214.71 0.34 235.94 ERR; ERR 215.71 0.34 23524 ERR _( ERR 216.71 0.34 234.54 ERR" ." ERR 217.71 0.34 233.85 ERR'r ERR 218.71 0.34 233.17 •ERR', ERR 219.71 0.34 232A9 ERR j ERR 220.71 0.34 231.81 ` ERR ": ``; ERR 221.71 0.34 231.14 ERR, ERR 222.71 0.34 230.48 ERR:y ERR 223.71 0.34 229.82 ERR; ERR 224.71 0.34 229.16 ERR a ERR 225.71 0.33 228.51 •.ERR_;»_%. ERR MOOIFIED RATIONAL METHOD EAST CATRON @ CATRON ST. Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 1509 ACRES STORM EVENT NTENSIT -STORM i COEFF (YR) (IN/HR) A B ?RE-DEV TC= ;' .0.00 MIN 0.00 HR 2 ERR 0.36 0.6 5 ERR j 0.52 PRE-DEV C= 0.2 10 ERR "0.64 0.65 (�2% ERR 0,7a 0.64 STORM A=' 0.78 50 ERR 0.92 "'0.66 B= ' _.0.64 100 ERR '. 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1509 ACRES POST-DEV TC= 186,00 MIN 3.10 HR POST-DEV C= 0.47 STORM INTENSITY= 0.38 IN/HR 10 YR POST-DEV Qp= 263.17 CPS DELTA DURATION= 1 MAX VOLUME `MAX VOLUME; T=AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (GF f� g (CFT) ERR : r4` ERREFiR� '.Triangle Release+Constant Release DURATION INTENSITY Op 'POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CPS) (CFT) s';") (CFT) (CFT) 176.70 0,39 277.12 ERR hY ERR 2093646.96 177.70 0.39 276.12 ERR p?R ERR 178.70 0.39 275.13 ERR..,+,, 2 ERR 179.70 0.39 274.15 ERR ,:; ERR 180.70 0.39 273.18 ERRS $''' ERR 131.70 0.38 272,21 ERR < '< ERR 182.70 0.38 271.26 ERR ERR 183,70 0.38 270.31 ` ERR ERR 184.70 0.38 269.33 ERR ERR 185.70 0.38 263.45 ERR ERR 188.70 0.38 267.53 ERRS<( ERR 187.70 0.38 266.61 ERR ERR 1B8.70 0.37 265.71 ERR ERR 189.70 0.37 264.81 ERR ERR 190.70 0.37 26392 ERR ERR 191.70 0.37 253 04 ERR ERR 192.70 0.37 252.15 ERR ERR 193.70 0.37 251.30 ERR "'=- ERR 194.70 0.37 250.4; ERR r ERR 195.70 0.37 259.59 ERR',"""'; ERR 196.70 0.36 25a.74 ERR ERR 197.70 0.36 257.90 ERR <;>' ERR 198.70 0.36 257.07 ERR r' ERR 199.70 0.36 255.25 ERR ."F ;j ERR 200.70 0.36 255.43 ERRi ' "'. ERR 201.70 0.36 25,62 ERR ERR 202.70 0.36 253.81 ERR r' ' ERR 203.70 0.36 253.01 ERR rs ERR 204.70 0.36 252,22 ERR 4'z ERR 205.70 0.35 251.44 ERR = ERR 206.70 0.35 250.66 ERR ERR 207.70 0.35 249.83 ERR ? ERR 208.70 0.35 249.12 ERR =y ERR 209.70 0.35 248.36 ERR`' a ERR 210.70 0.35 247.60 ERR, ' ERR 211.70 0.35 245.85 ERR j ERR 212.70 0.35 246.11 ERR t .: ERR 213.70 C.35 245.37 ERR.=^ ;'a ERR 214.70 0.34 244.64 ERR '# :<' ERR 215.70 0.34 243.91 ERR .r• y ERR 216.70 0,34 243.19 ERR" w ERR 217.70 0.34 242.43 ERR Ic > ERR 218.70 0.34 241,77 ERR ERR 219.70 0.34 241.06 ERR `"; ERR 220.70 0.34 240.36 ERR .> { ERR 221.70 0,34 23967 ERR , ERR 222.70 0.34 238.98 ERR " ERR 223.70 0.34 238.29 ERR ERR 224.70 0.34 237.61 ER R;r '.; ERR 225.70 0.33 236.94 ERR"`` ERR 226.70 0.33 236.27 ERR > ERR 227.70 0.33 235.61 ER ERR 228.70 0.33 234.95 ERR == `ji ERR 229.70 0.33 234.29 ERRS , - ERR MODIFIED RATIONAL METHOD EAST CATRON a@ CATRON ST. Op=CIA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ 1509 ACRES STORM EVENT NTENSIT ::STORM i COEFF (YR) (INlHR) A B ORE-DEV TC= 0.00 MIN 0.00 FIR 2 ERR 0.36 < 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR O.64 0.65 25 ERR 0.78 0.64 STORM A=., 1.01 50 ERR 0.92 ' 0.66 B= 0.67 d0 ERR 1.01 0.67 STORM INTENSITY= ERR IN/FIR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 1509 ACRES POST-DEV TO= 186.00 MIN 3.10 FIR POST-DEV C= 0.6 STORM INTENSITY= 0.47 IN/FIR 10 YR POST-DEV Qp= 428.5C CFS DELTA DURATION= 1 MAX VOLUh1E+{MAX1/OLUME, flAVERAGE VOLYI POND VOLUME CALCULATIONS: (CFT) , L ,(CFT) ERR =s a ERRS Triangle Release' Constant Release DURATION INTENSITY Op POND VOLUME POND VOLUME RETENTION VOL (MIN) (INrHR) (CFS) (OFT) (CFT) 176.70 0.49 443.48 ERR ERR 2672740.80 177.70 0.49 441.81 ERR ERR 178.70 0.49 440.15 ERR x + ERR 179.70 0.48 433.51 ;ERR +r. ERR 4 1:- 180.70 0.48 436-33 ERR 181.70 0.48 435.27 ERRS ERR 182,70 0.43 433.67 s-ERR 1 ''; ERR 183.70 0.48 432.09 :ERR', i ERR 184.70 0.48 433.52 ERR;-Y:;i`! ERR 185.70 0.47 428.95 ERR '; t ERR 186.70 0.47 427.42 'ERR. 5`. + ERR 187.70 0.47 425.89 ":,ERR ERR 183.70 0.47 424.33 ERR a -_' ERR 189.70 0.47 422 83 ERR ; ERR 190.70 0.47 421.39 ERR ERR 191.70 0.46 419 92 ERR ERR 192.70 0.46 418 46 "ERR ERR 193.70 0.46 417.01 ERR. :'-':'''.j ERR 194.70 0.46 415,57 ERR;'?.';= ERR 195.70 0.45 414.15 ERR ERR 196.70 0.46 412,74 ERR ';y ERR 19730 0.45 411.34 ERR ..: ERR 198.70 0.45 40995 ERR'' ERR 199.70 0.45 408.57 " ERR ERR 200.70 0.45 407.21 ERR ERR y=. ._ 201.70 0.45 405 65 ERR C : :j ERR 202.70 0.45 404.51 ERR ERR 203.70 0.45 403 18 "ERR ' i ERR 204.70 0.44 401.86 ERR,<..>, s ERR 205.70 0.44 400 55 ERR ''. ERR 206.70 0.44 399 25 ERR d " ERR 207.70 0.44 397-56 ERR -;`` ERR 208.70 0.44 39668 ERR U,'-)I ERR 209.70 0.44 355.41 ERR ERR 210.70 0.44 394,16 ERR ',,�z:( ERR 211.70 0.43 392.91 ERR r,::4q ERR 212.70 0.43 391.67 ERR ERR 213.70 0.43 390.44 ERR'd } ERR 214.70 0.43 389 22 ERR + " ''i ERR 215.70 0.43 3,1301 ERR ~j ERR 216.70 0.43 335 81 ERR '<;*;:( ERR 217.70 0.43 335 62 ERR s=; ERR 218.70 0.42 334.4, ERR, .,',„ ERR 219.70 0.42 383.26 ERR s j ERR 220.70 0.42 382.10 ERR -' .'. ERR 221.70 0.42 38094 ERR + ERR �a?4 222.70 0.42 37983 ERR ERR + 223.70 0.42 37866 ERR"W„A- ERR 224.70 0.42 377.53 c ERR"1',`_a ERR 225.70 0.42 37641 ERR '';ji ERR 226.70 0.41 375.29 �ERR ERR " 227.70 0.41 374.19 ERR ` ERR 228.70 0.41 37309 ERR . >' ERR MODIFIED RATIONAL METHOD WEST CATRON @ MINTEER ST. Qp=CiA PRE-DEVELOPMENT I=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 427 ACRES STORM EVENT NTENSIT :STORM 1 COEFF (YR) (IN/HR) A B PRE-DEV TC= 0.00 MIN 0.00 HR 2 ERR 0.36 :<` 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR 0.64 0.65 ERR 0.78 - 0.64 STORM A= 0.78 50 ERR 0.92 0.66 B= ' 0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 427 ACRES POST-DEV TC= i 245.00 MIN 4.08 HR POST-DEV C= 0.4 STORM INTENSITY= 0.32 INtHR 10 YR POST-DEV Op= 54,14 CFS DELTA DURATION= 1 MAX VOLUME lMA VOLUMEi (AVERAGE VOL, POND VOLUME CALCULATIONS: (CFT) ii(CF�7 ,1 �r (CFT) a '�`-ERR, � •x,A;�ERR .,��_ERR �,x; 7riangla Release Constant Release DURATION INTENSITY Qp POND VOLUME'I POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT) (CFT) (CFT) 23235 0.33 55.95 ERR ERR 504201.60 233.75 0.33 55.80 - ERR ;?j ERR 234.75 0.33 55.64 ERR t ERR 235.75 0.32 55,49 ERR e''.ry ERR 236.75 0.32 55.34 ERR 237.75 0.32 55.19 ERR r'j ERR 238.75 0.32 55.04 ERR ,', 3 ERR 23915 0.32 54.90 ERR .W ERR 240.75 0.32 54.75 ERRS ERR 241.75 0.32 54.61 ERR W ERR 242.75 0.32 54.46 ERR\wr<4h', ERR 243.75 0.32 54.32 ERR ERR 244.75 0.32 54.18 ERR ERR 245,75 0.32 54.04 ERR ERR 245.75 0.32 53.90 ERR}?`=-`- ERR 247.75 0.31 53 76 ERR,.,`- :� ERR 243.75 0.31 53.62 ERR ', -"{ ERR 249.75 0.31 5348 ERR ' ERR 250.75 0.31 53.34 ERR ((">'- ERR 251.75 0.31 53.21 ERR i ERR 252.75 0.31 53.07 ERR ``',. ; ERR 253.75 0.31 52.94 ERR «'; ERR 254.75 0.31 52.81 ERR: : `` ERR 255.75 0.31 52.67 "ERR,,, ,`r ERR 256.75 0.31 52.54 ERR "i' +l ERR 257.75 0.31 52.41 ERR",; ERR 258.75 0.31 52.28 ERR ``' '; ERR 259.75 0.31 52.15 ERR F,�'1,;i'1 ERR 260.75 0.30 52.03 ERR ;ti ERR 251.75 0.30 5t90 ERR ERR 262.75 0.30 51.77 ERR ERR 263.75 0.30 51.65 ERR ; ERR 264Y5 0.30 51.52 ERR_,'- ":I' ERR 265.75 0.30 51.40 ERR ' ERR 256.75 0.30 51.27 ERR i y ERR 267.75 0.30 51.15 ERR ERR 268.75 0.30 51,03 ERR - ERR 269.75 0.30 50.91 ERR:p! ERR 270.75 0.30 50.79 - ERR,'---__ a ERR 271.75 0.30 50.67 ERR ;, ERR 272.75 0.30 50 55 ERR ERR 273.75 0.30 50,43 ERR ERR 274.75 0.29 50,31 ERR ERR 275.75 0.29 50.20 ERR"•+."':; ERR 276.75 0.29 50.08 ERR *> 1 ERR 277.75 0.29 49,96 ERR, '. '`i ERR 278.75 0.29 43.85 ERR ERR 279.75 0.29 4974 ERR ERR 230.75 0.29 49,62 ERR6 ...,. ERR 281.75 0.29 49,51 ERR ERR 282.75 0.29 49.40 ERR .>.J ERR 283.75 0.29 49.29 ERR_, ERR 284.75 0.29 49 17 ERR ;� ERR 285.75 0.29 49,06 ERR_?- .'y ERR - MODIFIED RATIONAL METHOD WEST CATRON @ DURSTON RD. Qp=CIA PRE-DEVELOPMENT I=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 200 ACRES STORM EVENT NTENSIT STORM 1 COEFF (YR) (IN/HR) A B °RE-DEVTC= + '!'' 0,00 MIN 0.00 FIR 2 ERR 0.36 0.6 S ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR O.M4 0.65 2 ERR 0.78 .0.64 STORM A=" 0.78 50 ERR 1.0.92 0.66 B= 0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 200 ACRES POST-DEV TC= 103.00 MIN 1.80 HR POST-DEV C= 0.3 STORM INTENSITY= 0.54 IN/HR 10 YR POST-DEV Qp= 32A3 CFS DELTA DURATION= 1 MAX VOLUME ,MAX VOLUME ,AVERAGE VOL POND VOLUME CALCULATIONS: (CFS Triangle Releases Constant Release DURATION INTENSITY Qp POND VOLUME'S POND VOLUME RETENTION VOL I.(MIN) (INIHR) (CFS) (CFT) `` (CFl) (CFT) 102.60 0.55 33.20 ERR,; Z14 ERR 177120.00 103.60 0.55 32.99 ERR ' ERR 104.60 0.55 32.79 ',ERR;:`,-:j ERR 105.60 0.54 32.59 ERR >"') ERR 106.60 0.54 32 40 ERR i} ERR 107.60 0.54 32.20 ERR ERR 106.60_ 0.53 32.01 ERR 109.60 0.53 31.83 "','ERR ": ERR 110.60 0.53 31.64 ERR •;' 1 ERR 111.60 0.52 31.40 ERR 112.60 0.52 31.28 ERR 3 ERR 113.60 0.52 31.10 ERR ; ERR 114.60 0.52 30.93 „ERR ,1 ERR 115.60 0.51 30.76 •ERR,_..,.v`r;:;,� ERR 116.60 0.51 30.59 ERR z°r' ERR 117.60 0.51 30.42 ERR ERR 118.60 0.50 30.26 ERR ERR 119.60 0.50 3010 ERR ERR 120.60 0.50 29.94 ERR '' ERR 121.60 0.50 29.78 ERR ', ERR 122.60 0.49 29.62 ERR ERR 123.60 0.43 29 47 ERR ERR 124.63 0.49 29.32 ERR_, ERR 125,60 0.49 29.17 ERR `;, ERR 126.60 0.48 29.02 i ERR t ERR 127.60 0.43 25.87 ERR 's. ERR 128.60 0,43 28.73 "_ ERR iS ERR 129.60 0A8 28.59 ERR;`":*'j ERR 130.60 0.47 28.45 ERR ERR 131.60 0.47 28.31 ERR ``i ERR 132.60 0.47 23.17 ERR ERR 133.60 0.47 23.0.1 ERR ERR 134.60 0.47 27.90 'ERR": ERR 135.60 0.46 27.77 ERR;'`:i ''y ERR 136.60 0.46 27.64 ERR ERR 137.60 0.46 27.51 ERR + ERR 138.60 0.46 27.39 ERR s a ERR 139.60 0.45 27.26 ERR "'_ ERR 140.60 0.45 27.14 ERR ERR 141.60 0.45 27.01 ERR ERR 142.60 0.45 26.89 ERR ERR 143.60 0.45 26.77 ERR -T"' ;'1 ERR 144.60 0.44 26.65 ERR . -'I ERR 145.60 0.44 26 54 ERR `_, ERR 146.60 0.44 2642 ERR ;.', y ERR 147.60 0.44 2531 ERR :` ERR 148,60 0.44 2519 ERR,,'. " ERR ! 149.60 0.43 26.08 ERR A ERR 150.60 0.43 2597 ERR .^ ERR 151.60 0.43 25.86 ERRu ;; ERR 152.60 0.43 25.75 ERR ERR 153.60 0.43 25.64 ERR H; ERR 154.60 0.43 2554 r ERR ERR MODIFIED RATIONAL METHOD WEST CATRON @ BAXTER LN. Op=CiA PRE-DEVELOPMENT 1=a'(DURATION)^-(b) (CITY OF BOZEMAN) BASIN AREA PRE ACRES STORM EVENT NTENSIT ':STORM i COEFF, (YR) (IN/HR) A B °RE-DEV TC= :'0.00 MIN 0.00 HR 2 ERR 0.36 0.6 5 ERR 0.52 0.64 PRE-DEV C= ;,'0,2 10 ERR "0.64 >0.65 25i ERR 0.78 0.64 STORM A 0.78 50 ERR 0.92 0.66 B= 0,64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 386 ACRES POST-D=_V TC= `228.00 MIN 3.80 HR POST-DEV C= 0.3. STORM INTENSITY= 0.33 IN/HR 10 YR POST-DEV Qp= 38.44 CFS DELTA DURATION= 1 MAX VOLUME MAX VOLUME l CAVERAGE VOL h y POND VOLUME CALCULATIONS: (CFT) .c (CFT) ( FT) ERR , ERR �u E ;ERR .Triangle Release Constant Release DURATION INTENSITY Op POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CF7) ? ? (CFT) (CFT) 216.60 0.34 39.72 ERR' ERR 341841.60 217.60 0.34 39.60 ERR ERR 218.60 0.34 39.49 ERR', ERR 219.60 0.34 39.37 ERR ERR 220.60 0.34 39.26 ERR ERR 221.60 0.34 39.14 ERR =s ERR 222.60 0.34 39.03 ERR .*: ERR 223.60 0.34 38.92 ERR 2 ERR 224.60 0.34 33.81 ERR ERR 225.60 0.33 38.70 ERR ERR 226.60 0.33 38.59 ERR, ;"- ERR 227.60 0.33 35.45 ERR': ERR 228.60 0.33 38.37 ERR ERR 229.60 0.33 38.26 ERR` " ERR 230.60 0.33 38.16 ERR; `' ERR 231.60 0.33 38.05 ERR ERR 232.60 0.33 37.95 ERR < ERR 233.60 0.33 37.84 ERR ': ERR 234.60 0.33 37.74 ERR ERR 235.60 0.33 37.64 ERR ERR 235.60 0.32 37.54 ERR -: ERR 237.60 0.32 37.44 ERR.;'' ERR 233.60 0.32 37,33 ERR` ERR 233.60 0.22 37.23 ERR ERR 240.60 0.32 37.14 ERR '' ERR 241.60 0.32 37.04 ERR=.`_.; ERR 242.60 0.32 36.94 ERR 7 ERR 243,60 0.32 36.84 ERR,; ERR 244.60 0.32 36.75 ERR <+ ERR 245.60 0.32 36.65 ERR ERR 246.60 0.32 35,55 ERR ERR 247.60 0.31 36.46 ERR ^.`. ERR 248.60 0.31 36.37 ERR;j ERR 249.60 0.31 36.27 ERR;';'`,' ERR 250.60 0.31 36.18 ERR;;;: ERR 251.60 0.31 36.09 ERR : , ERR 252.60 0.31 36.00 ERR ERR 253.60 0.31 35.91 ERR "i ERR 254.60 0.31 35.82 ERR;'.`'. ERR 255.60 0.31 35.73 ERR ERR 256.60 0.31 3564 ERR ?t:: ERR 257.60 0.31 35 55 ERR,.".; ERR 258.60 0.31 35.46 ERR ' ERR 259.60 0.31 35.37 ERR ' . ERR 260.60 0.30 35.29 ERR >''.- ERR 261.60 0.30 35,20 ERR` ERR 262.60 0.30 35.11 ERR ERR 263.60 0.30 35.03 ERR ;<• ERR 264.60 0.30 34.94 ERR ERR 265.60 0.30 34.86 ERR } ERR 266.60 0.30 34.78 ERR,,, ERR , 267.60 0.30 34.69 ERR. ERR 268.60 0.30 34.61 ERR .:` ERR 269.60 0.30 34.53 ERR,. ERR MODIFIED RATIONAL METHOD WEST CATRON @ SEITZ ST. Qp=CiA PRE-DEVELOPMENT 1=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= 404 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN1HR) A B PRE-DEV TC= i b.00 MIN 0.00 HR 2 ERR 0.36 0.6 5 ERR 0.52 '0.64 PRE-DEV C= 0.2 0 ERR 0.64 0.65 ERR 0.78 0.64 STORM A '0.78 50 ERR 0.92 0.66 B=''• ; 0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 404 ACRES POST-DEV TC= 235.80 MIN 3.93 HR POST-DEV C= 0.35 STORM INTENSITY= 0.32 IN/HR 10 YR POST-DEV Qp= 45.93 CFS DELTA DURATION= 1 MAX VOLUME b fW VOLUME' AVERAGE VOL j POND VOLUME CALCULATIONS: {CFT) ERR $; JERKa Triangle,Rele'ase Constant Release DURATION INTENSITY Op 'POND VOLUME,tt POND VOLUME RETENTION VOL (MIN) (INIHR) (CFS) ;(CFT) `z'N (CFT) (GFT) �r 224.01 0.34 47.47 ERR ERR 417412.80 225.01 0.33 47.33 ERR 226.01 0.33 47.20 ERR = •'i ERR 227.01 0.33 47.06 ERR ,;, ERR 228.01 0.33 46.93 ERR ERR 229.01 0.33 46.80 ERR ' ERR 230.01 0.33 46.67 ERR tiff .:a ERR 231.01 0.33 46.54 ERR a}w :'! ERR 232.01 0.33 46.41 ERR r` ^ ERR 233.01 0.33 45.29 ERR ERR 234.01 0.33 45.16 ERR ERR 235.01 0.33 45.03 ERR ERR 235.01 0.32 45.91 ERR"' ERR 237.01 0.32 45.78 ERR ERR 233.01 0.32 45.66 ERR ERR 239.01 0.32 45.54 ERRj j _ ERR 240.01 0.32 45A2 ERR ERR 241.01 0.32 45.30 ERR ERR 242.01 0.32 45.18 ERR ERR 243,01 0.32 4506 ERR ERR 244.01 0.32 44.94 ERR ERR 245.01 0.32 44.82 ERR z ' ERR 246.01 0.32 44.70 ERR, .;<-`.,i ERR 247.01 0.32 44.59 ERR ERR 248.01 0.31 44 47 ERRs�� ?< ERR 249.01 0.31 44.36 ERR ERR 250.01 0.31 44.25 ERR ,,: ERR 251.01 0.31 44.13 ERR ". ':.;• ERR 252.01 0.31 44.02 ERR ERR 253.01 0.31 43.91 ERR ERR 254.01 0.31 43.80 ERR '. ERR 255.01 0.31 43.69 ERR c ERR 256.01 0.31 43.58 ERR :` ERR 257.01 0.31 43.47 ERR ERR 25a.01 0.31 43.36 ERR ERR 259.01 0.31 43 26 ERR ERR 260.01 0.31 43.15 ERR ERR 261.01 0.30 43.04 ERR ` ;�:; ERR 262.01 0.30 42.94 ERR ';_: =r; ERR 263.01 0.30 42.83 ERR ERR 264.01 0.30 42.73 ERR ERR 265.01 0.30 42.63 ERR'; ERR 266.01 0.30 42.52 ERR ERR 267.01 0.30 42.42 ERR ERR 268.01 0.30 42.32 ERR ERR 269.01 0.30 42.22 ERR ERR 270.01 0.30 42.12 ERR : ERR 271.01 0.30 42.02 ERR;ti; ERR 272.01 0.30 41.92 ERR:'`.k` ERR 273.01 0.30 41.82 ERR.' ERR 274.01 0.30 41.72 ERR• s:� ERR 275.01 0.29 41.63 ERR ` ERR 276.01 0.29 41.53 "ERR' :, i;'. ERR MODIFIED RATIONAL METHOD WEST CATRON @ DEADMAN'S GULCH Qp=CiA PRE-DEVELOPMENT i=a'(DURATION)A-(b) (CITY OF BOZEMA,1) BASIN AREA PRE= f:„'` ,423 ACRES STORM EVENT NTENSIT >?STORM i COEFF 'RE-DEV TC= `;0.00 MIN 0.00 HR (2R) (IN/HR) 0.36 0.6 PRE-DEV C= 5 ERR 0.52 0.64 0.2 10 ERR 0.64 > 0.65 (25,) ERR OJ8 0.64 STORM A 0.78 50 ERR 0.92 0.66 B ,+• ,<`0,64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Op= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 428 ACRES POST-DEV TC= .1.245.00 MIN 4.13 HR POST-DEV C= 0.4 STORM INTENSITY= 0.31 IN/HR 10 YR POST-DEV Op= 63.85 CFS DELTA DURATION= 1 t+tAX VOLEY-fUME'-MAX VOLUME; +AVERAGE VOL POND VOLUME CALCULATIONS: (CFT) (CF7) ERR a " 7(CFT} Triangle Release j Constant Rela...ease DURATION INTENSITY Op POND VOLUME POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFT} , (CFT) ;a (CFT) 235.60 0.33 55.64 ERR R i ERR 505382.40 236.60 0.32 55.49 ERR 237.60 0.32 55.34 -"•:;ERR i ERR 238.60 0.32 55.20 ERR ERR 239.60 0.32 55.05 IERR r'� a ; ERR 240.60 0.32 54,90 ERR t { ERR 241.60 0.32 54.76 `;ERR ERR 242.60 0.32 54.61 '.ERR 11 ERR 243.60 0.32 54.47 ;,ERR �} ERR 244.60 0.32 54.33 ERR a ( ERR 245.60 0.32 54.19 ERR -) ERR 246.60 0-32 54.04 'ERR ERR 247.60 0.31 53.90 ERR ERR 248.60 0.31 53.76 ERR ERR 249.60 0.31 53.63 ERR ERR 250.60 0.31 53.49 ERR ERR 251.60 0.31 5335 ERR ERR 252.60 0.31 53.22 ERR ERR 253.60 0.31 53.08 ERR ERR 254.60 0.31 52.95 ERR ERR 255.60 0.31 52.82 `ERR. ERR 256.60 0,31 52,69 ERR ERR 257.60 0.31 52.55 ERR ERR 258.60 0.31 52A2 ERR ', ERR 259.60 0.31 5229 ERR ERR 260-60 0.30 52.17 ERR ERR 261.60 0.30 52.04 ERR ERR 252.60 0.30 51,91 ERR ,,.;`. ERR 263.60 0.30 51.79 ERR i ERR 264.60 0.30 51.66 ERR ,;r,( ERR 255.60 0.30 51.54 ERR ERR 266.60 0.30 51.41 ERR ERR 267.60 0.30 51.29 ERR '7 ERR 268.60 0.30 51.17 ERR ERR 269.60 0.30 51,05 ERR ERR 270.60 0.30 50.92 ERR ERR 271.60 0.30 50.80 ERR ERR 272.60 0.30 5063 ERR ERR 273.60 0.30 5057 ERR ERR 274.60 0.29 50.45 ERR t ERR 275.60 0.29 5033 ERR ERR 276.60 0.29 5021 ERR ERR 277.60 0.29 5010 ERR ERR 278.60 0.29 49.98 ERR ERR 279.60 0.29 49.87 ERR , ERR 280.60 0.29 4976 ERR . ERR 281.60 0.29 49 E4 :'ERR r " ERR 282.60 0.29 49.53 ERR ' ERR 283.60 0.29 4942 ERR t _7 ERR 284.60 0.29 .49 31 ERR ERR 235,60 0.29 49.20 ;;ERR ) ERR 286.60 0.29 4909 ERR s i ERR 287.60 0.29 4693 ERR ".:' ERR MODIFIED RATIONAL METHOD WEST-CATRON @ CATRON ST. Qp=CiA PRE-DEVELOPMENT I=a.(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE= t•';, 436 ACRES STORM EVENT NTENSIT = STORM i COEFF (YR) (IN/HR) A. B PRE-DEV TC= 0,00 MIN 0.00 HR 2 ERR ;0.36 0.6 5 ERR 6.52 0.64 PRE-DEV C= „ 0.2 10 ERR 0.64 0.65 C2•$� ERR 0.78 : 0.64 STORM A= 0.78 50 ERR 0.92 "' 0.66 B= 0.64 100 ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 436 ACRES POST-DEV TC= `,'300.00 MIN 5.00 HR POST-DEV C= 0.41 STORM INTENSITY= 0.28 IN/HR 10 YR POST-DEV Qp= 49.78 CFS DELTA DURATION= 1 MAX VOLUME MAXUO'LUME IAVERPGE VOL POND VOLUME CALCULATIONS: (CFT) - ERR t4ERR,:�i';'! Triangle Release�Constant Release UM DURATION INTENSITY Op POND VOLE 4 POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) {CFS -.') (CFT) (CFT) 285.00 0.29 51.4 ERR ERR 527699.52 286.00 0.29 51.32 ERR 287.00 0.29 51.21 ERR *" ERR 208.00 0.29 51.09 ERR V tij ERR 289.00 0.29 50.98 ERR ;`.>i ERR 290.00 0.28 50.87 ERR '-, ? ERR 291.00 0.28 50.76 ERR 'I ERR 292.00 0.28 50,65 ERR } ERR 293.00 0.28 50.53 ERR ERR 294,00 0.28 50.42 ",ERR,,kid�,t ERR 295.00 0.28 50.31 ERR��t�[z6' ERR 296.00 0.28 50.21 ERR •'.'.eI ERR 297.00 0.28 50.10 ERR ERR 298.00 0.28 49.99 ERR ERR 299.00 0.28 49.86 ERR:,Y? ;; ERR 300.00 0.23 49.78 ERR 'c ERR 301.00 0,28 49.67 ERR "_; ERR 302.00 0.28 49.57 ERR ERR 303.00 0.28 49.45 ERR ° ERR 304.00 0.28 49.36 ERR ;•;.;; ERR 305.00 0.28 49.25 ERR ERR 306.00 0.27 49.15 ERR 3 ERR 307.00 0.27 49.05 ERR ERR 308.00 0.27 48.95 ERR ` ; ERR 309.00 0.27 43.84 ERR •1'-"' ERR 310.00 0.27 48,74 ERR kr,» ERR 311.00 0.27 48.64 ERR <` ERR 312.00 0.27 48,54 ERR ERR 313.00 0.27 48.44 ERR :;;< ERR 314.00 0.27 43 34 ERR"?;i°_, ERR 315:00 0.27 43 25 ERR ERR 316.00 0.27 4?t5 ERR W ERR 317.00 0.27 43.05 ERR ERR 318.00 0.27 47.95 ERR ERR- 319.00 0.27 47.85 ERR ':" ERR 320.00 0.27 47.76 ERR ;, ERR 321.00 0.27 47.67 ERR ERR 322.00 0.27 47.57 ERR i ERR 323.00 0.27 47A3 ERR i ERR 324.00 0.27 47,38 ERR r, `'• ERR 325.00 0.26 4729 ERR ERR 326.00 0.26 47,20 ERR ERR 327.00 0.26 47.11 ERR ._t,4 ERR 328.00 0.26 47,01 ERR r ` ERR 329.00 0.26 46.92 ERR z <j ERR 330.00 0.26 46.83 ERR, i r ERR 331.00 0.26 46.74 ERR ;4 ERR 332.00 0.26 46,65 ERR " -> ERR 333.00 0.26 46.56 ERR" ERR 334,00 0.26 4647 ERR t :;a ERR 335.00 0.26 46 38 ERR `A ERR 336.00 0.26 46,29 ERR ft a ERR 337.00 0.26 45.21 ERR `' ERR ERR 338.00 0.26 46,12 , _: _? ERR MODIFIED RATIONAL METHOD WEST CATRON @ DEADMAN'S GULCH Qp=CIA PRE-DEVELOPMENT 1=a'(DURATION)A-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ :;• 428 ACRES STORM EVENT NTENSIT STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= 0.00 MIN 0.00 HR 2 ERR 0.3E 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR 0.64 0.65 25 ERR 0.78 0.6-4 STORM© ;'�0.01 so ERR 00 ERR 0.92 0.66 .01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Qp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 428 ACRES POST-DEV TC= 248.00 MiN 4.13 HR POST-DEV C= .0.6 STORM INTENSITY= 0.39 IN/HR 10 YR POST•DEV Qp= 100.23 CFS DELTA DURATION= 1 ' _MAXVOLUME MAXVOLUME` AVERAGEVOL7I POND VOLUME CALCULATIONS: (CFT) ERR..ERR ERR Triangle Release;I Constant Release DURATION INTENSITY Op POND VOLUME.3 POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) (CFTj w�`'' (CFT) (CFT) 235.60 0,40 103.73 -ERR ERR 758073.60 236.60 0.40 103.44 ERR ' ERR 237.60 0.40 103.15 ERR. ;'z?;f ERR 238.60 0.40 102.8E ERR %ri ERR 239.60 0.40 102.57 ERR ; ERR 240.60 0.40 102.28 ERR 4 !,`i ERR 241.60 0.40 102.00 ERR xi ERR 242.60 0.40 101.72 ERR ';`y ERR 243.60 0.40 101.44 . ERR ERR 244.60 0.39 101.16 ERR 'i ERR 245.60 0.39 100.88 :'ERR 1' :.-; ERR 246.60 0.39 100.61 ERR ERR 247.60 0.39 100.3-1 ERR ',`' ERR 248.60 0.39 100.07 ERR?;>:'•'.`• ERR 249.60 0.39 59.80 ERR ERR 2$0.60 0.39 99.53 ERR ERR 251.60 0.39 99.27 ERR '` ERR 252.60 0.39 99,00 ERR " ERR 253.60 0.38 98.74 ERR ••+ ERR 254.60 0.38 98A8 ERR ERR 255.60 0.38 93.22 ERR - `'::ri ERR 256.60 0.38 97.97 ERR .•', ERR 257.60 0.33 97.71 ERR ERR 253.60 0.33 97.46 'ERR '''.• ERR 259.60 0.38 97.21 ERR;; : ERR 250.60 0.38 96.96 ERR ERR 251.60 0.38 96.71 ERR ERR 252.60 0.38 96.46 ERR,.a,: ERR 263.60 0.37 96.22 ERR ERR 264.60 0.37 95.97 ERR ERR 265.60 0.37 95.73 ERR ERR 266.60 0.37 95.43- ERR ERR 267.60 0.37 95.25 ERR 1` ERR 268.60 0.37 95,01 ERR -'_ ERR 269.60 0.37 94.78 ERR "`'' ERR 270.60 0.37 94.54 ERR - ERR 271.60 0.37 94.31 ERR `, ERR 272.60 0.37 94.08 ERR ERR 273.60 0.37 93.84 ERR -. ,' ! ERR 274.60 0.36 93.62 ERR ' ERR 275.60 036 93.39 ERR c' ERR 276.60 0.36 93.1E ERR ERR 277.60 0.36 92.94 ERR ERR 278.60 0,36 92.71 ERR >;'. ERR 279.60 0.3E 92.49 ERR ERR 280.60 036 92.27 ERR " ERR 281.60 0.36 92.05 ERR.,-".. ERR 282.60 0.36 91.83 ERR's?'c`-<I ERR 283.60 0.36 91.61 ERR ' ! ERR 284.60 0.36 91.40 ,ERR ` ERR 285.60 0.3E 91.18 ERR ` ``•? ERR 286.60 0.35 9097 ERR ERR ERR ERR 287.60 0.35 90.7E 'i.` ,' MODIFIED RATIONAL METHOD WEST CATRON @ CATRON ST. Op=CIA PRE-DEVELOPMENT 1=a'(DURATION)"-(b) (CITY OF BOZEMAN) BASIN AREA PRE_ .436 ACRES STORM EVENT NTENSIT : STORM i COEFF (YR) (IN/HR) A B PRE-DEV TC= < 0.00 MIN 0.00 HR 2 ERR 0.36 0.6 5 ERR 0.52 0.64 PRE-DEV C= 0.2 10 ERR 0.64 0.65 25 ERR 0.78 0.64 STORM A `1.01 50 ERR 0.92 0.66 B= 0.67 Qi) ERR 1.01 0.67 STORM INTENSITY= ERR IN/HR PRE-DEV Cp= ERR CFS POST-DEVELOPMENT BASIN AREA PRE= 436 ACRES POST-DEV TC= ' 300.00 MIN 5.00 HR POST-DEV C= _ 0.6 STORM INTENSITY= 0.34 IN/HR 10 YR POST-DEV Cp= $9.88 CFS DELTA DURATION= 1 MAX VOLUME* MAX VOLUME) EAVERAGE VOE'•i POND VOLUME CALCULATIONS: (CFT) (CFT) {CF fj 47 i -'ERR .. ;ERRJL Triangle Release:')Constant Release DURATION INTENSITY Op `POND VOLUME 1 POND VOLUME RETENTION VOL (MIN) (IN/HR) (CFS) ,,(CFT)y,x (CFT) (CFT) 285.00 0.36 93.02 �!ERR� r? ERR 772243.20 286.00 0.35 92.80 vERR r40 ERR 287.00 0.35 92,58 ERR ERR 288.00 0.35 92.37 :ERR ERR 289.00 0.35 92.15 ERR i ERR 290.00 0.35 91.94 i>ERR ERR 291.00 0.35 91.73 ERR` ,, ERR 292.00 0.35 91.52 ERR N�3;'u ERR 293.00 0.35 91.31 ERR ERR 294.00 0.35 91.10 ,..ERR _;; ERR 295.00 0.35 90.89 ERR ;: ERR 296.00 0.35 90.69 ERR ERR 297.00 0.35 90.46 ERR ERR 298.00 0.35 90.28 ERR ERR 299.00 0.34 90.08 ERR ERR 300.00 0.34 89 68 ERR ERR 361.00 0.34 89.68 ERR ERR 302.00 0.34 89A8 ERR ERR 303.00 0,34 89.28 ERR .' ERR 304.00 0.34 89.08 ',ERR,- ERR 305.00 0.34 88.59 ERR ERR 306.00 0.34 88.69 ERR ERR 307.00 0.34 Ba.50 ERR ERR 303.00 0.34 83.31 ERR ERR 309.00 0.34 88.11 ERR ERR 310.00 0.34 87.92 ERR ERR 311.00 0.34 87.73 ERR j ERR 312.00 0.33 87.55 ERR ERR 313.00 0.33 87.36 ERR ERR 314.00 0.33 87.17 ERR ERR 315.00 0.33 86.99 ERR ERR 316.00 0.33 85.80 ERR ERR 317.00 0.33 86.62 ERR ERR 318.00 0.33 86.44 ERR ERR 319.00 0.33 86.25 ERR ERR 320.00 0.33 86.07 ERR ERR 321.00 0.33 85.89 ERR ERR 322.00 0.33 65.72 -ERR 'j'7; ERR 323.00 0.33 85.54 ERR : `;.,' ERR 324.00 0.33 85 36 ERR ERR 325.00 0.33 85.13 ERR ERR 326.00 0.32 85,01 ERR ERR 327.00 0.32 84 83 ERR, ;: `; ERR 328.00 0.32 84.66 ERR`- . ERR 329.00 0.32 84A9 ERR ERR 330.00 0.32 84 32 ERR "''§. ERR 331,00 0.32 84.15 ERR i, ERR 332.00 0.32 8398 ERR', ' ERR 333.00 0.32 8181 ERR ERR 334.00 0.32 8364 ERR,- ` ERR 335.00 0.32 83.47 ERR ;::'': ERR 336.00 0.32 83.31 ERR: ERR 337.00 0.32 83,14 ERR •,i".`„+ ERR 338.00 0.32 82.97 ERR. ERR - CULVERT NOMOGRAMS The Gallatin Center Subdivision Phase 1 {�' ,,am. .32".:�'T.�,'�s:..�-cZ;-;�:1'-'a;<�;'---.. - �.- K:rTf--:-._ - --•;^`-;o:a-'-,-': - =�_ NUAL FIGURE S 289 I FIGURE 92 CULVERT CAPACITY �H 27 x 44-INCH (RISE x SPAN) ARCH -AR EQUIVALENT 36-INCH CIRCULAR 20 • F ..... 1 I , 1 F I 13 r Manning s n=0.012r I i ! ' u'-, Projecting Inlet 2 :..... Outlet Unsubmerged -1 : Approx.Equivalent Circular _.:i:•' i' _.._.___..:.__:, '_ _. O 16 Size Based on Periphery _ �= o ......... a to _. .. .. . _ i o LL O __�- --— _.• � '� t—._.—_.__—!__.r_.____--�~� by 1_ _ __-- ••'�- %. p LU - - - — — — ----- ----— I �� i ;.: Et COtdTRO; OUTLET:CO`JTRO!c ....i:..: _... -- — -•e-/ Z I ......— - -..L.:.._....__ -_� :...:...E..7 i 8 l' O . / Q V f I J b 1 ..._...._..... _ 1 ; i. LL � . �� : f I r i. .. •.j 0 D0 60 70 20 40 60 80 100 120 140 T PER SECOND CULVERT DISCHARGE Q IN CUBIC FEET PER SECOND �� SScF's M I Q = 6,o �. 290 CONCRETE PIPE DESIGN MANUAL C) nJ 1 . � � O O FIGURE 93 _ II CULVERT CAPACITY N/ s CFS ? 31 x 51•INCH (RISE x SPAN) ARCH 3 p�,pry FIGURE 94 EQUIVALENT 42_INCH CIRCULAR 00 20 >.:._.:..._ _ 1 E +- �I - t •i. 1 ..4..,, t 18 i w - f- Projecting n=0.012 I i w Inlet 1 B Z • Outlet Unsubmerged Q O APProx.Equivalent Circular �1 F 16 Size Based on Periphery ` _ ' Z _ �I Z + i it N O o Z 16 o i 0 14 ' Lu ' t •• r•.i'... O= 14 cc LL II Q 12 - Toq + 1 O �. �h�, ..t 1 12 LL �ry 1 tih Q _ t o - , a j > I w 10 f Z w t durt�r_caKrR:a: _ _ w Z Z ;._ - J 8 O - 4 _ 0 • f i- Z f- _ - GQ 6 ��. 4 .;• 1 ' O _i.y :.:i.:. 6 ..i... .. Z 1 v) :. w --- + T 4 \) LL - .-.._ t. Lu ;.;.�.�,,, Z) \ i 2 0 .......:._...... - 1 40 b0 80 100 120 140 0 CULVERT DISCHARGE Q IN CUBIC FEET PER SECOND 160 50 75 .d r-0S'+• 7 +'''X� 5 2, '' '7 it �' t �. 9 ♦ _ ,•� n;.w"r•4" i"i — d4 sit�.a•`F R" «•� r a.t tf M t 'f - �+ �' >yai5 jX i rp =iri >� +*:� +'". � r-ry �'-.+. ' 7��' ; �,��5. 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'.� f .`.urq�SLq�y.�...i", a7'•'+�.. �' ..,,Y" kart;{:}�G^c Fir.S' '`?:�.,{,.�s`,r�itr�?s�".{.r,�4wy{F! *,J Ac .l.'�;`^4 fp}`T'.'i:wF,r�'t'`�`..Y ,!"'�{.t„' .._'�c{i.,'y�j"��.�+�'1�n';e'�'..laz'i�".[4� w�''�;f4 t s�'., 1{•�.�.%.•;' LJ;Wr+;f{ �'vRf•.t, tr t�v�::^'r� ..�t::s,. ?}• ift ....ti Y ��...�* d � �' ��a,;,�f�fcr�t,��yv�'•?4':g .'.;- .:fi�'YBrt1•.::r f,Yr?,{w f,,�E;`•,'(;�:t`#r^Y"6• b?y'i r1i°7y �b .�.-:�,y ,ft, ar.. r�t�..r,xJ,J� .y a}.5, %S;i•�,h t�yy 3• r w`xt.4o }"f!�T M� A,.s 3X �'f"b' i .t.` :r,°:"rr �:Lti,i':4 ,,.a�j/ ,:..;rK. ;.1,..:y:yf F.*x.y "h;•�`"� ..X ^ '1i Any .M,� yi,,i y' .•. *�i'1''�:4 ysa' s7z•,,"s jtE;!i..f�i+�;�z1 t�,.` •.:its�+f.. a''{��i '?a.Fi k'a is `F: i,t>.X y�4•• ," :wrt�,.° r x a 3;}r,, : •<:y�,a,4�,,�r rt y. s 't[K J. t•C�'..yrt..lx_r�n t�};�'t r'p'iMF vs ,fir, 9v sF r`t•..�•e.:.•, t., � .c i:.1'N•-�.A,.,•"' n � y+ :.3t >f..,:Y,:t* x�..xa.e��'say��k"'3a�.sls�:•?�'S."2 w{, 'v�'�rv'lhCt • • • • • • • • • • • • • • • • L-4J, II-71 5,000 -- I6'-7'x 10'-1' 4,000 a~ 42� ' 15'-4'x 9'-3' 3,000 EXAMPLE Site: 36•x 22' 2,000 0. 20 cfl 3 4 - Hwe ttw 3 1 o w 0 (feet) 3 e �N 11'-5'x 7'-3' 1,000L (l) Llo 2.0 l+o (2) 1.15 2.1 2 C J :6 O t` 800 (3) 1.22 2.2 9'-6' x 6'-5' z v V 600 •0 in feet 2 2 500 N8'-2'x 5'-9' 400 — 300 1.5 1.5 7'-0'x 5'-1' 200 v6'-1' x 4'-7' G: 1.0 — a 2' x 44' 100 // 1.0 ..0- Z 80 1.0 LL p 65`z 40' O 60 +pj% N 9 50 / g- 58'x 36' 40 // 8 .8 0 / o x Q Z 0 30 / a 5 0'x 31' _O / cr 7 .7 N 20 F / HW SCALE ENTRANCE ? •7 w p N 43'z 27' TYPE / r (I) Heod.all a .6 10 .6 (2) Alilered to conform 8 _ tailo Ix •6 36'x 22' w o (3) Projecting H a 6 3 z 5 0 a C .5 ~ 4 w .5 .5 N To via seals (2)or(3) Project = 29'x 18' 3 horixonlallr to scale (1),then uxs straight Inclined line through _ 0 and 0 scales, or reverse as 25'x 16' 2 Illustrated. .4 4 :4 2 2'x 13' 1.0 B z 0 18' z t l' 5 .35'6 .35 .35 HEADWATER DEPTH FOR C. M. PIPE-ARCH CULVERTS BUREAU OF PUBLIC ROAOS JAN.1963 WITH INLET CONTROL �-rr1 tb c./L--1 f 11-64 300 _ H HW �. 200 Slop• So--. SUBMERGED OUTLET CULVERT FLOwiNG FULL HW.H•ho-LSo u For oulltl Cron hol wbmIr9Id. Compul• HW bT = W en'lhod, dMCrib�d iR tho deli n ¢ z C Proddw� CK J .4 100 O 90 aJ b0 .5 80 Z .6 60 6 5-X 40' "� 0 w 7 �0 w 8 50 u <'� Z 9 o; 58'X36' Z 0 1.0 �0 u 4 0 U O'4O d 0 a 2 4 50'X31' —EXAMp w 30 aL \ - ,Lp O x O O \ N.1.7 Lai w 43'X27" 200 \ tD _N a 20 2 x x 300 U � 0 a 36'X2Y <�3e0 300 : 9 3 w 400 N 400 N 4 10 29'X18' 9 5 8 500 0 5 7 25'X16' 6 6 7 8 5 9 10 4 HW --r3 �'�a -� a `z �o DigYr� HEAD FOR STANDARD Q M. PIPE-ARCH CULVERTS FLOWING FULL BUREAU OF PU80C ROA03 JAN. 1963 n=0.024 NATURAL CHANNEL CROSS SECTIONS The Gallatin Center Subdivision Phase 1 > o m m !A ro z 3 _o 4 o u) N 0 ca 0 L ti OC:D C 00 to U o (T3 v � O � O N U Q. o cc C/) tL �— o � L o O .0- L N U � o O U � U N [n cn E co O U) O u L � t'- U 0 N L � Q. O .0 E C (0 cn O O O O C) _ C � U • N 0 0 0 � tOL 00M000 � L3 -0 t/T O O O CVc- O c- CO N O C C �C fll R5 U) U O 0 O U N O L1 O-0 vvi � � a 0 o Dena 0 a) E N � N O + a. .0 N 'O ILL C N U U u) L U O O C U) E to •� L 3 7 C C " �O V U (0 Q .. O O >O O O N .� O .N LLB > li � U) cn � U � JEmoC) c a) c ' N tD In O O \ \/ o ) & 3 { J . � z . < . : R 1 . 8 p � o / . Q co U ' C) 8 ( '0 . \ . / CL £ _ @ ) § M \ E 0 5 * � § ~ _ U 2 /Q / e 2 O f � m o m E \ U E . . \ ( ¥ � 2 ± - 0' / \ CL g CD / . k _ � � CD � a > > \ Co / � 2 _ / § R R R % � � / � C) C) o .Eo 2 duo oo0oq / � 3 7 p a a g a Q) § '§ 2 k § LA§ E r E o o m 5 3 \ E 6 Eo e a • o : y e0aQQ � Ea £ Q _o D a) § L- - = Q 6 y 7— o \ / / k k n § / 2 g £ 5 k0k � 32i wm C p / } o co CI. • c o 0 0 0 o g 06 ° 9 , k k k k k k E \ / . w e o # n A 8 [ \ Lr) fu r vfu A N 0^ C4 a ' 3 n� _o V LL 4 � f— S Z 9 oAS N co co N M O � N... C C w «C � U C6 U _ O O N c m U O o `° O � C cB U w s � ~ o L Cy O O ) C O _Y O L o (D N CO E h co v- 0 C- V O U c L N U o [Z L E U N co N cu C C O 0 0 = cu s "C3E C7 0 0 ULL OOOOOOM 'o -0 N N Ci C7 CV M c*? tt? cn N C co O O C .0 O Q- C U O (B N C U O {— �GC� O U Q � O V C co O Q 0- 0 .0 cv .. N - U o ow - N '_ O N Cn a) O W O O O co C C '� C� 0 C 3 > � ccan c � U n`_ n`_ � u � U coU � . , � m0 co r m � N C L7 N O O _ N ri a 3 0 L N cm L LO = Q o C N "C o U n 0 cc -0 U O ON c cu10 o Z a U N (n Y U E m U a 2 � Q• O O o L' r L E c O o c > > c� d N C 5 0 c E 000 _ U o 0 00 ro c u LL N O_ 0 0 X O t�B nm 00000 C15 to N C O a C7 C13 0 O O C C M CL C U C O CU C U O I- �c C) O Lq E O O •U Q N E O N Q U C O II 0 .9-- C O E ` sn � � o cv Cll o c cn— m t3 co U v W p Ll' .c .0 *- CO 3 > N c = 6 � o s o aooOo ocoa a cia � ti � CA ottYM CL p 0 o a o 0 o ao rno O0 LO 0 o Q Q o ' o N � N N LO 00 M co Lti 00