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Vulnerability of Manitou’s Mineral Springs Aquifer and Williams Canyon Flood Channel Contributing Factors Williams Canyon Flood Channel 1/14/2015 Presented to Manitou Springs City Council 11/1/2016 by Dave Wolverton Contents Watersheds Above the Manitou Springs Aquifer 4 Contributed Watersheds 5 Geology of Manitou Springs and Vicinity 6 Manitou Springs Aquifer Hydrogeologic Setting 7 Karst Type Aquifers 8 Aquifer Recharge 9 Williams Canyon Flood Channel 10 Best Management Practices 13 Waldo Canyon Fire Influences 15 U.S. Highway Corridor and Associated Risks 16 Recommendations 17 Supporting Links 17 Preface Deep ecology is a philosophy of the connected environmental inter-relationships of an entire ecosystem. The overall health of the Manitou Springs aquifer ecosystem is vulnerable and threatened due to human- caused influences. The intent of this document is to explain how and why Manitou Springs’ aquifer re- charge is susceptive and suggests steps to mitigate threatening circumstances. As residents and policymakers, we must consider the deep ecology of a resource branding our community. Sustaining the pristine character of the ecosystem is in the best interest of all stakeholders. 3 67 N LEGEND Contributing Watersheds MN SCALE 1 1/2 0 1 Mile Williams Canyon Creek Watershed Drainage basins contributing recharge to the Manitou Springs Fountain Creek Watershed WatershedsWatersheds AboveAbove Ruxton Creek Watershed Woodland Park aquifer are primarily Fountain Creek and Williams Canyon Creek Paved Two Lane Road Graded Gravel Road thethe ManitouManitou MineralMineral watersheds. The map on the previous page illustrates the locations of Fountain Creek depicted in green and Williams Canyon Creek SpringsSprings AquiferAquifer depicted in red. The importance of the map is to show proximity to 24 Manitou Springs and area extent of each basin. Both watersheds include land within Pike National Forest. The 2012 Waldo Canyon fire caused significant impact to watershed areas impacting both Fountain Creek and Williams Canyon Creek significantly. An important detail to call out is the U.S. Highway 24 transportation corridor adjacent to Fountain Creek, discussed later in this document. Fo u n t North ai Catamount n Cr Reservoir ee South k Catamount Reservoir Crystal Creek Reservoir W i l 24 l i d a a m o R s e C g a n a n Manitou R y t Reservoir o r n a p C m a r R e e k ek re Manitou Ruxton C Springs Pikes Peak Big Tooth Reservoir Lake Moraine 4 5 Rampart Range Fault Manitou Springs Aquifer Hydrogeologic Setting From the 2011 Shomaker report (pgs 91-93) - “The map on the previous page shows a dramatic boundary along the Front Range between the very old granite and metamorphic rocks of the Rocky Mountain block, uplifted on the west side of a fault zone (or in places a monoclinal fold) of great displacement, and the Great Plains block on the east. In one area of a few square miles, however, the small remnant of early sedimentary rocks at Manitou Springs, some of the oldest sedimentary rocks in the region are preserved on top of the granite and metamorphic rocks in the upthrown Rocky Mountain Manitou block, west of the great bounding faults of the Front Range. The small Ute Pass Fault remnant of old sedimentary rocks preserves beds of the Manitou Springs Limestone and the thin underlying Sawatch Sandstone and Peerless Remnant Dolomite, and a thick sequence of overlying units including the Leadville Limestone and the Fountain Formation. These rocks have been removed by erosion from much of the area of the mountain block. The sedimentary strata in the preserved remnant generally dip to the east, toward the bounding fault, and for that reason, the wedge- shaped sequence of beds is thickest at its eastern limit. The Manitou Limestone, and parts of the immediately underlying sandstone and weathered granite, and overlying dolomite and limestone beds, Great Plains constitute the Manitou Springs artesian aquifer, and the Fountain Formation serves as a sequence of low-permeability confining beds Block above it.” Rocky Mountain Block Ute Pass Fault Geology of Manitou Springs and Vicinity MN SCALE 1 0.5 0 1 MILE 10 O 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET 1 COLORADO 0.5 0 1 KILOMETER CONTOUR INTERVAL 20 FEET NATIONAL GEODETIC VERTICAL DATUM OF 1929 QUADRANGLE LOCATION 6 7 PERIOD PERIOD MEMBER MEMBER Fountain Creek Williams Canyon FORMATION FORMATION Fountain Formation f ~299 - 318 Million years ago PLIOCENE PLEISTOCENE PLIOCENE PLEISTOCENE Up to 4,050 feet of red and white, coarse-grained, arkosic sandstone and pebble to boulder conglomerate, medium-to-thickly bedded conglomeratic sandstone. This is an aquiclude. Glen Eyrie Member of FOUNTAIN P fg FOUNTAIN Manitou Springs PENNSYLVANIAN Fountain Formation PENNSYLVANIAN Maximum thickness of 362 feet, black to blue-gray ~318 Million years ago shale and lesser amounts of varicolored blue-green to Generalized purple shale and orange-tan sandstone beds. GLEN EYRIE GLEN EYRIE An aquiclude. Stratigraphic Hardscrabble Member of Correlation MDlh Leadville Limestone ~318 - 360 Million years ago Not exceeding 100 feet, tan to gray, sandy dolomitic of Fountain Creek limestone. Massive-bedded carbonates, upper part LEADVILLE LEADVILLE MISSISSIPPIAN MISSISSIPPIAN HARDSCRABBLE HARDSCRABBLE consists of well-indurated karst breccia. An aquifer. and Williams Canyon Williams Canyon Limestone Dwc ~360 - 416 Million years ago Approximately 30 feet, distinguished by thin bedding and bright red color. An aquifer. WILLIAMS CANYON WILLIAMS CANYON DEVONIAN DEVONIAN *LTD Manitou Formation *LTD Om ~444 - 488 Million years ago About 160 feet of pinkish-gray to tan, thin wavy-bedded to medium bedded carbonates giving way to an upper cliff-forming, dolostone, about 30 feet thick. An aquifer. MANITOU MANITOU ORDOVICIAN ORDOVICIAN PTARMIGAN CHERT PTARMIGAN PTARMIGAN CHERT PTARMIGAN HELENA HELENA CANYON CANYON Sawatch Sandstone Approximately 57 feet. Lower sequence is s ~488 - 542 Million years ago white-to-light-gray-green sandstone passing upward into dolomitic sandstones of deep purple and green SAWATCH SAWATCH CAMBRIAN CAMBRIAN color. A limited aquifer. Pikes Peak Granite Ypp ~1.02 - 1.08 Billion years ago Unknown thickness. Pink to light reddish-brown, Unknown thickness. Potassium feldspar-biotite coarse-grained, locally porphyritic granite. migmatite, quartzose gneiss, biotite schist, and Migmatitic gneiss Weathering produces grüs amphibolite gneiss that are intruded by the Pikes MIGMATITIC GNEISS Xgn PIKES PEAK GRANITE PRECAMBRIAN ~1.66 - 1.79 Billion years ago PRECAMBRIAN (loose granular disintegration). Peak Granite. An aquiclude. * LEAVICK TARN DOLOMITE * LEAVICK TARN DOLOMITE Digital Elevation Model with Surface Geology Overlay of Manitou Springs and U.S. Highway 24 Karst Type Aquifers Aquifer Recharge From the 2011 Shomaker report (pg 105) - “The type aquifer that Confining geologic layers above and below the carbonate rock supplies the mineral springs is formed principally by fractures, and strata (listed as aquicludes on stratigraphic correlation graphic - fractures that have been enlarged by solution of carbonate rocks, in previous page) encompassing the Manitou Springs aquifer primarily the upper part of the sequence of limestone beds of the Ordovician- restricts recharge to stream sections where aquifer host strata is age Manitou Limestone, but also in overlying limestone beds of the directly exposed to stream flows. The image above illustrates sections Devonian-age Williams Canyon Limestone and Mississippian-age of Fountain Creek and Williams Canyon Creek crossing strata where Leadville Limestone. The aquifer also appears to include sandstones of most recharge from surface sources occurs. The amount of recharge the Sawatch Sandstone which underlies the Manitou, and weathered each drainage basin contributes is controlled by the amount of stream granite beneath the Sawatch.” flow in Williams Canyon. Williams Canyon Creek begins to cross Carbonate rocks, enlarged by solution, eroded into caverns and the carbonate strata recharge section approximately 300’ higher in caves are categorized as karst type aquifers. Expressed in Williams elevation than Fountain Creek. When consistent flows occur, this Canyon as Cave of the Winds, the cavernous system of carbonate rock condition raises the level of the aquifer to a level above the recharge strata dips under the city of Manitou Springs. Cave of the Winds, now section in Fountain Creek. From a deep ecology perspective, the above the water table, is a dormant part of the aquifer system. The environmental ecosystem in Williams Canyon is much more pristine underground cavernous system dipping under the city fills with water than that of Fountain Creek reducing vulnerability caused by human- and becomes the mineral springs karst aquifer. induced influences significantly but not entirely. 8 9 Williams Canyon Flood Channel Lower Basin Construction 8/26/2014 Williams Canyon Flood Channel Lower Basin 1/9/2015 Flood Channel Condition Before Construction 10/31/2013 Flood Channel Recharge Blocks Installation 9/30/2014 Recharge Blocks Installation Detail Showing Perforated PVC 9/30/2014 Constant Flow of Groundwater Into Lower Basin Corrugated Drain Pipe Channeling Runoff From U.S. Highway 24 Williams Canyon Flood Channel After completion, a number of problems with the channel have been identified. A steady flow of groundwater emitting from A recent development is the Williams Canyon flood channel underground into the lower catchment basin is out of character constructed in the lower canyon section in 2015. The project was from pre-flood channel conditions. A situation where groundwater fast-tracked by the City of Manitou Springs in response to the has little or no chance of providing recharge to the aquifer. During devastating effects caused by the Waldo Canyon fire in 2012. Wright pre-construction meetings, former City Administrator Jack Benson Water Engineers, Inc., contracted to design the flood channel, were indicated a deliverable component of the flood channel engineering made aware of the critical aspects of the Manitou Springs aquifer by contract included a maintenance manual. The maintenance manual local citizens during the design phase of the project.

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