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HomeMy WebLinkAboutMONTAVA - PHASE D CORE AND IRRIGATION POND - BDR240006 - SUBMITTAL DOCUMENTS - ROUND 3 - Responses (9)Bushong & Holleman PC A t t o r n e y s · a t · L a w 1966 13th Street, Suite 270, Boulder, Colorado 80302 MEMORANDUM To: Tyler Marr, Todd Sullivan, Heidi Hansen , Eric Potyondy, Ted Bender, Wes Lemarque, Jill Oropeza, Jill Baty, Brad Yatabe, Clay Fricky From: Steve Bushong Date: September 11, 2024 RE: Follow up on Phase D stormwater drainage meeting on 8-28-24 Thank you for meeting with the Montava team on August 28, 2024, to discuss Phase D stormwater drainage issues. We came away from the meeting with the following issues that would benefit from further discussion: (1) whether the box culvert point source into the Larimer & Weld Canal (“LWC” or “Ditch”) was approved by the 1986 AB Agreement with LWIC (“Agreement”); (2) the drainage pathway from the Phase D outfall to the box culvert; (3) available aerial photographs showing historical drainage through the box culvert into the LWC; and (4) next steps under the City’s Stormwater Criteria Manual (“Manual”) and timing of box culvert improvements. Based on the information provided previously and herein, we believe the City should agree that the Agreement explicitly allows stormwater from AB lands west of the railroad to discharge through the box culvert and into the LWC, controlled only by flow rate not volume. This provides a path forward under the Manual as further explained below. I. The Agreement approves the box culvert point source into the LWC. The following is a summary of our interpretation of the Agreement related to the box culvert under the railroad, how that interpretation is consistent with the facts, and recently discovered documents that further verify our understanding and interpretation. Before discussing the Agreement, it is important to clarify the meaning of “point source” used repeatedly in the Agreement. Under the Clean Water Act (“CWA”), “[t]he term ‘point source’ means any discernable, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, [or] conduit …” that discharge into waterways. CWA § 502(14). Although the CWA uses the term point source in the context of a discharge of pollutants, the Agreement used this term to describe AB’s allowed method of discharge into the Ditch to distinguish it from nonpoint sources, which are diffuse and uncontrolled discharges (e.g. stormwater moving over ground and not contained within a point source). https://www.epa.gov/nps/basic-information- about-nonpoint-source-nps-pollution. Accordingly, as used in the Agreement, a point source is simply a confined structure or channel that discharges drainage into the Ditch. 2 A. The Agreement expressly allows multiple point sources into the ditch located east of the railroad and one existing point source from lands lying west of the railroad. The recitals set the stage for the Agreement. The AB lands subject to the Agreement included “natural and historic drainage of stormwater … into the Ditch.” (2nd Recital). The AB Agreement not only addressed the brewery being constructed east of the Railroad, but also “development in the future of the remainder of the aforesaid lands,” which included all of AB’s lands west of the railroad. (See 3rd Recital; see also map showing AB lands described in the 1986 Agreement attached as App’x A). As explained further below, it is undisputed fact that AB’s lands west of the railroad naturally and historically drained to the box culvert. The Agreement specifically grants AB the right to discharge stormwater into the Ditch “from specific point sources,” with the “aggregate of all such point sources [limited] to a rate of flow rate not in excess of that historically to be expected once every one-hundred years.” (¶¶ 1.a and 1.b). Not only does this make clear that it was the flow rate – not the volume – of stormwater that was being controlled as is also expressly discussed in the recitals, but that AB was allowed multiple point sources into the Ditch. Paragraph 2.b states that “[a]ny new point sources of stormwater entry into the Ditch constructed by A-B pursuant to paragraph 1 above shall be located east of the right-of-way of the Burlington Northern Railroad….” While this makes it clear that AB can construct multiple new point sources into the Ditch east of the railroad where the brewery was being constructed, stormwater west of the railroad was treated differently in paragraph 2.c., as follows: [T]here currently exists only one (1) point source of stormwater entry into the Ditch which conveys into the Ditch stormwater from A-B’s land lying west of the right-of-way of the Burlington Northern Railroad…. [Although] said existing point source [may be relocated,] … at no time during the term of this Agreement shall A-B cause or permit point-source drainage into the Ditch from its lands lying west of said right-of-way in excess of the design capacity and historic flows of said existing point source. Paragraph 2.c is necessarily describing the existing box culvert under the railroad – and not the Birky pipeline as LWIC alleges – for the following reasons: • ¶ 2.b addresses “point sources of stormwater entry into the Ditch … located east of the railroad.” The Birky pipeline is a point source into the Ditch that is located entirely east of the railroad as shown by the pipeline certification we shared with you previously and, as described in the Birky Order, was constructed to help address a water problem existing east of the railroad. • In contrast to ¶ 2.b, ¶ 2.c describes an existing “point-source drainage into the Ditch from [AB’s] lands lying west of said [railroad] right-of-way.” The only such point source from lands lying west of the railroad is the box culvert which feeds a ditch or channel that discharges directly into the Ditch. The Birky pipeline is not a point source from lands lying west of the railroad as it lies entirely east of the railroad and collects water east of the railroad for discharge into the Ditch. • The fact that some lands west of the railroad right-of-way and mostly north of AB contribute to the drainage east of the railroad doesn’t change the locations of the point 3 sources described in the Agreement. Further, ¶ 2.c recognizes there “historically existed” “waters arising west of said right-of-way [that were] … discharged from structures east of said right-of-way,” and the Birky pipeline is such a structure. But ¶ 2.c still grants AB the right to continue discharging from a “point-source … from its lands lying west of said right-of-way.” • LWIC’s argument that the existing point source described in ¶ 2.c refers to the Birky pipeline is not only inconsistent with the above language – but also illogical. It would mean that even though AB was allowed multiple point sources into the Ditch located east of the railroad limited only by the 100-year historic rate as stated in ¶ 2.b, one of those point sources located east of the railroad (the Birky pipeline) was nonetheless limited to its current design capacity. Further, LWIC’s argument would mean the vast majority of AB’s lands west of the railroad that were included in the Agreement and historically drained to the box culvert and discharged into the Ditch were not addressed. B. The known historical condition supports Montava’s interpretation. The stormwater model shows the railroad creates a stormwater divide. 75% or more of the watershed drainage naturally and historically drained on the west side of the railroad to the box culvert. This includes all of Phase D and most of AB’s land west of the railroad. See Stormwater Model Map attached as App’x B. The stormwater model also shows that up to 25% of the watershed drainage lies east of the railroad. See App’x B. The inundated area east of the railroad was described in the Birky Order as being just north of CR 50 and the Birky lands and is visible in the 1975 aerial photograph depicted below. The water consisted of drainage arising east of the railroad and a portion of the drainage from the north and west of the railroad that crosses under the railroad. The Birky pipe helped address this 25% problem and the pipeline certification shows it was constructed entirely east of the railroad. By 1977, the ponding area east of the railroad and north of CR 50 is no longer visible in the aerial photograph depicted below. 1975 Aerial Photograph CR 50 & 125 4 1977 Aerial Photograph CR 50 and I25 Montava’s reading of the Agreement is consistent with these undisputed facts. The existing point source that the model shows historically drained 75% of the stormwater west of the railroad is retained, but may be relocated, repaired or maintained as needed, while AB is given the right to install additional point sources east of the railroad for its brewery site. LWIC’s reading of the Agreement would deprive AB of any drainage west of the railroad even though AB has prescriptive drainage rights west of the railroad that pass through the box culvert. C. New AB documents found by Montava further support its common sense interpretation. Montava has searched for AB drainage studies and attached is what it has found. First is a December 22, 1999 letter and December 1999 hydrology report prepared by AYRES Associates regarding an expansion to the AB brewery site and attached as App’x C. The report discusses in several places how the “historic drainage conditions were documented in the ‘Drainage Report for Site Master Plan and Phase 1 PUD, Anheuser-Busch Companies, Inc., Fort Collins, Colorado’ (RCI, November, 1983).” (PDF pg. 8). Although a complete copy of that 1983 report has not been found, attached to the end of the 1999 report are pages from the November, 1983 report prepared by Resource Consultants Inc. (RCI) describing the historic drainage referenced in the report (note the figure contains the date of November, 1983). The most pertinent paragraph in the 1983 report reads as follows: Drainage waters exit the 1,130-acre site at three locations under existing conditions. The first exit is through an existing culvert under the railroad at approximately the center of Section 4. This drainage water then enters the Larimer & Weld Canal. The second point of release is through an existing 18-inch drain tile located in the Northeast ¼ of section 4 which also drains into the Larimer & Weld Canal. During extreme storm events, storm water will pond along County Road 50 at the inlet to the drain tile, overtop the county road, and flow through the field in the Northeast ¼ of Section 4 into the Larrimer & Weld Canal. The third area of release is from the Northeast ¼ of Section 4. Storm water currently flows through a series of culverts under the canal maintenance road and into the Larimer & Weld Canal. (PDF Pg.26). 5 This description of the drainage conditions precisely parallels Montava’s plain reading of the Agreement. The section map attached as App’x D shows the center of Section 4 is approximately the same location as the box culvert under the railroad, meaning it was a recognized existing point source to the Ditch in 1983. The 18” drainage line in the Northeast ¼ of Section 4 is entirely east of the railroad and in all likelihood represents the Birky pipe constructed in that ¼ section. The third point source is also east of the railroad and the infrastructure is still apparent on the ground. In other words, the historic condition included one point source for lands west of the railroad (i.e. the box culvert) and multiple point sources east of the railroad (including the Birky pipeline). The 1983 report is the best evidence of what the existing drainage conditions were like at the time of the 1986 AB Agreement and what the parties were trying to address in that Agreement. The inclusion of the 1983 report into the 1999 report shows that even though modeling assumptions had changed, the historical conditions understood to exist in 1983 were still deemed to be accurate in 1999. Also, further expressing the language in the Agreement, the 1983 Figure 2 master plan shows substantial development was planned west of the railroad. The 1999 report itself describes the Agreement as allowing “developed conditions runoff into the canal at historic rates,” while actually lowering the historical rate similar to Montava’s proposal for Phase D. (PDF pg. 12). Further, the Existing Conditions map (Figure 3) from the 1999 Report shows drainage flowing west of the railroad to a “ponding area” with a label referring to a 2’ x 1’ box in the same location as the historical 2’ x 1’ box culvert. See excerpt of Figure 3 below. Montava also found an AB Master Drainage Plan dated January, 2009, attached as App’x E, which is another example of how the known drainage patterns correspond to the plain language of the Agreement and AB’s stormwater planning. The existing conditions map in the 2009 report shows drainage pathways both west and east of the railroad, with the west drainages converging at the box culvert in an existing water detention area. See excerpt of map below. 6 This is also shown in the existing conditions schematic in the 2009 Report, with stormwater connections west and east of the railroad going directly into the LWC as expressly allowed by the Agreement. (PDF pg. 7). Accordingly, the 2009 report further documents that AB’s stormwater planning has always remained consistent with a plain reading of the Agreement and the historical condition – which allows the box culvert point source into the Ditch. II. The drainage pathway from the Phase D outfall to the box culvert are consistent with the City’s Drainage Criteria. A question arose at the meeting on whether the Phase D outfall would discharge into a channel. The City’s Stormwater Criteria Manual Ch. 1 § 2.2.5 recognizes that upgradient lands have “natural easements over down-gradient properties for the drainage of waters flowing in their natural course and manner.” “Water also naturally flows into channels, creeks, streams, and other naturally occurring drainage ways … [and] they are generally considered to be the best and most appropriate location of stormwater conveyance systems.” Id. See also Id § 2.2.6 (4) and (6) (discussing the advantages of natural drainage ways and vegetated channels). The stormwater model shows the historical stormwater drainage pathways west of the railroad that drained to the box culvert. See App’x B. This is the same pathway shown in the 2009 AB drainage report and is also clear in the 1999 and 1983 AB Reports. Also, attached as App’x F is a recent survey of the land below Phase D that shows a large natural depression running through the AB land to the box culvert. That is the historical drainageway that the Phase D outfall discharges into and was likely a tributary to Cooper Slough before the LWC was constructed and intercepted the drainage. This approach also satisfies the City’s requirement that projects “have a gravity outfall and adequate downstream conveyance for said outfall.” Manual, Ch.2, § 4.1(1). 7 III. Aerial photographs document that the box culvert point source into the Ditch existed at the time of the Agreement and ever since. Only briefly discussed at our meeting was the 1969 aerial photograph LWIC provided that shows a feint line across the canal below the box culvert point source, which LWIC suggests was historically a way to pipe the water over the Ditch. While it’s not clear what the feint line is, it was not there for very long and did not exist historically, or at the time of the Agreement in 1986, or anytime thereafter. Instead, what is clear from the available aerial photographs is that historically a ditch or channel connected the box culvert to the Ditch and would have acted as a point source of stormwater discharge into the Ditch. Attached as App’x G is a list of the aerials we have compiled and a link so you may review them all yourselves. As you will see, the feint line over the Ditch that LWIC noted is only apparent in 1969 and 1972 (1973 is less clear). In all other aerials, before and after that time, including at the time of the Agreement, no line across the Ditch is visible. Also, a channel, ditch, or dark drainage pathway extending from the box culvert to the Ditch (i.e. a point source) is visible in the aerials, showing the historical point source discharge. If LWC is correct that the feint line that existed from 1969 to 1972 represented a way that the LWIC once passed historical drainage water from the box culvert over the Ditch rather than into the Ditch, it could consider doing so again with appropriate approvals. However, per the Agreement, AB was granted the right to discharge stormwater drainage into the Ditch at that location. The following are excerpted aerials from 1937, 1973, 1986, and 1992, depicting the historical condition, condition at the time of the Agreement, and post-Agreement condition. 1937 1973 8 1986 1992 IV. Next steps under Manual and timing of box culvert improvements. At the meeting we also discussed whether and when Montava would start the process of improving or replacing the box culvert. Before discussing relevant provisions of the Manual and proposed next steps to allow Montava to move forward in a timely fashion, it is important to remind the City of the practical effect of Montava’s proposal. As the Manual recognizes, “it is virtually impossible to prevent increases in post-development runoff volumes for all storm events when an area urbanizes. Peak flows must be controlled to predevelopment levels. Increases in runoff volumes are managed to minimize adverse impacts on stream stability.” Manual, Ch. 1, § 8.b. For that reason, stormwater detention designed to reduce the rate of stormwater runoff to historical conditions and which can help address stormwater volume in smaller more common storm events, coupled with other measures to reduce runoff, is the traditional standard recognized by the City. See, e.g. Manual Ch. 7 § 2. In this instance, Montava has proposed using stormwater detention to reduce the developed 100- year discharge associated with the Phase D lands to historic 2-year rates. That will significantly reduce the historical (pre-developed) rate at which stormwater leaves Phase D and passes through the natural drainage ways to the box culvert and into the LWC. The proposed detention will also help reduce stormwater volumes in smaller more common events through infiltration, but some increased stormwater volumes are expected in larger events as the Manual recognizes. Further, the stormwater model shows that the proposed Phase D detention will not adversely impact the inadvertent detention that can occur at the railroad in large events. Moreover, as was discussed at the meeting and above, the Agreement recognizes the ability to discharge increased stormwater volumes into the LWC so long as the rates discharged into the Ditch at point sources are less than or equal to the historical 100-year rate and Montava is reducing the rate below that requirement. We believe Montava’s proposal satisfies the requirements in the Manual. See Manual Ch. 2 §§ 4.1, 4.2. We are not aware of any requirement in the Manual that would require a developer to go “downstream” and construct improvements in stormwater infrastructure except perhaps stabilizing stream channels where needed. Such stabilization on the drainage pathways is not expected to be necessary given the significant reduction in stormwater rate. However, consistent with our conversation at the meeting, Montava is in the process of analyzing how best to proceed with 9 improving or replacing the box culvert and solicited a proposal from Martin/Martin on design. Montava will also initiate communications with BNSF in the near future for necessary approvals to construct an improved drainage structure. Since the Agreement already recognizes that AB “may repair, maintain, or relocate said existing point source as it deems necessary or desirable ,” further LWIC approval is not needed so longs as the design capacity of the culvert remains the same. (Agreement, ¶ 2.c). Montava has a cost sharing agreement with the City to share in the cost of stormwater improvements within the Upper Cooper Slough watershed. That would include sharing the cost of designing, permitting, and constructing an improved structure at the box culvert. However, this improvement is not needed for Phase D because of the proposed significant reduction in the historical runoff rate from the Phase D lands. In other words, the amount of stormwater leaving Phase D and eventually passing through the box culvert will be substantially reduced compared to the historical condition. It is also important to recall that Phase D represents only a small percentage of the Cooper Slough watershed that drains to the box culvert. Accordingly, Montava requests that approvals for Phase D and for construction of homes within Phase D not be delayed for an improved or replaced box culvert that is not needed for Phase D. However, Montava is willing to commit to the shared cost of design, permitting, and construction of the box culvert if it does not slow down said approvals. Based upon initial communications with BNSF, permitting the improved or replaced box culvert will likely take about 18 months. Lastly, despite its prior Agreement, LWIC appears to now be opposed to any stormwater discharges into the LWC. Its important to recall that Montava previously proposed to pass all stormwater from Montava under and over the LWC into the lower Cooper Slough, but that concept was never accepted by LWIC along with Montava’s proposed crossings of Canal No. 8 needed to develop Phases E and G. While the Agreement is clear that stormwater from the AB lands shown in App’x A may be discharged directly into the LWC subject only to the rate limits described in the Agreement, Montava remains willing to discuss with LWIC ways to deliver stormwater past the LWC as part of a larger resolution. V. Conclusion The Phase D drainage issues should be straight forward. Phase D lands have historically drained entirely west of the railroad through a natural drainageway to the box culvert and into the Ditch. Not only are there prescriptive rights for that natural drainage to continue, but contractual rights with LWIC clearly exist to continue that practice as described in detail above. By reducing the developed 100-year discharge of stormwater runoff leaving Phase D to the historic 2-year rate, Montava’s proposal exceeds the standard set forth in the Agreement and will reduce the use of both the stormwater drainageway and the box culvert under the railroad. Further, the stormwater drainageway is located on land that Montava will be acquiring from AB and will no doubt be improved when those lands are later developed. Accordingly, we request the City approve the Phase D drainage plan as proposed by Montava.