The New California Water Atlas

Making water understandable in California

Chacha Sikes

The California Department of Water Resources has 515 PDFs that give valuable descriptions and 'metadata' about the various groundwater basins across the state.

We converted these PDFs to text files, and want to get them into tabular data format (well, CSV, comma-separated, data).

The files are all in this git repository on Github.

Yesterday, Laci called the DWR to ask them if they had this information in tabular format, and they don't - but people keep calling to ask. We would like to help them help the citizens of California.

If you feel inclined to help clean up this data, please have at it!

We are adding a README that lists the fields.

The project

  1. Write a scraper in the language of your choosing (we prefer nodejs and python, but php and ruby are fine.)
  2. Parse the 515 text files:
  3. Create a CSV data table structure with machine-friendly column names.
  4. Populate the CSV with the data.


  1. Convert also to a JSON document with an ID based on the basin unit ID.

Sign up

Just tweet at us or email us to let us know you want to volunteer to tackle this. You can fork the repo and send us a pull request.

A preview of the data

This is the text of one file. You can see how there is lots of useful information in it. If it were in tabular format, it could more easily be used in interactives that help us visualize and understand groundwater.

Central Coast Hydrologic Region Soquel Valley Groundwater Basin
Soquel Valley Groundwater Basin
• Groundwater Basin Number: 3-1
• County: Santa Cruz
• Surface Area: 2,500 acres (4 square miles)
Basin Boundaries and Hydrology
The Soquel Valley Groundwater Basin is bounded to the south by Monterey Bay, and to the north by a series of hills that define the contact of Quaternary and Pliocene deposits (Purisima Formation) at or near the Zayante Fault.
The western boundary coincides with the western boundary of the Soquel Creek Water District. The eastern boundary is generally the coastward projection of the drainage divide between the Soquel and Aptos Creek watersheds. In addition to the areas of Quaternary deposits, the eastern limit of the Soquel Creek and Central Water District’s service area may be considered the basin boundary for the purposes of managing and monitoring groundwater resources in the area. Soquel Creek is the major drainage in the Basin. Average annual precipitation is 25 inches along the coast to 29 inches inland.
The adjoining basins include West Santa Cruz Terrace to the west and the Pajaro Valley to the southeast.
Hydrogeologic Information
Water-bearing sediments consist of the Pliocene Purisima Formation, which is overlain by Quaternary terrace deposits, and the Pleistocene Aromas Red Sands Formation. The Purisima and Quaternary terrace deposits have been locally incised by streams filled with Quaternary alluvium (Muir 1980). The Purisima Formation is exposed along Monterey Bay where it is a cliff- forming unit. The Aromas Red Sands Formation extends into the Pajaro Valley Basin.
Water Bearing Formations
The Purisima Formation, of Pliocene geologic age, is a sequence of gray, sometimes described as blue, moderately consolidated, silty to clean, fine to medium sandstone containing siltstone and claystone interbeds (Greene 1977). It has not been explored to basement north of the Soquel Creek Water District’s (SCWD) boundaries but is thought to terminate at or near the Zayante Fault. The granite basement surface, which is uniformly sloping to the southeast, is approximately 450 feet beneath sea level at the western SCWD boundary, and approximately 1,300 feet beneath sea level at approximately Valencia Creek. Farther to the southeast, the Purisima continues to dip at the same rate, but is overlain by predominantly unconfined Aromas Red Sands (SCWD 2003).
Based on the lithologic and geophysical logs developed during the installation of SCWD’s network of production wells and monitoring wells, combined with other water well logs and a few geophysical logs of oil and gas borings in the vicinity, seven distinct subunits of the Purisima Formation have been identified and designated AA, A, B, C, D, E, and F, from deepest to shallowest (LSCE 1984). Groundwater occurs in all the subunits of the Purisima beneath the Soquel-Aptos area. Except in the vicinity of its outcrop
California’s Groundwater Bulletin 118
Central Coast Hydrologic Region Soquel Valley Groundwater Basin
at the surface, the Purisima subunits are confined by claystone or siltstone interbeds. In general, fresh water is introduced into the various Purisima subunits through the recharge areas, or outcrop locations, of the subunits and then flows through the respective subunits generally toward Monterey Bay (SCWD 2003).
The Aromas Red Sands Formation is brown to red, poorly consolidated, fine to coarse-grained sandstone containing lenses of silt and clay (LSCE 1996). The formation consists of upper eolian and lower fluvial sand units that are separated by confining layers of interbedded clays and silty clay (RMC 2001). Based on limited lithologic and geophysical logs and other geologic data, the Aromas is underlain by the Purisima Formation throughout the eastern third of the Soquel-Aptos area, although the exact depth of the contact has not been identified. Essentially unconfined throughout the Soquel-Aptos area, the Aromas Red Sands contain fresh water above a wedge-shaped intrusion of seawater which is about 200 feet below sea level at the coastline and slopes away form the coast to nearly 500 feet below sea level in the vicinity of the SCWD Seascape and Altivo supply wells (SCWD 2003).
Restrictive Structures
There are no known restrictive structures in the Soquel Valley Basin. Groundwater flow in the Soquel Valley portion of the confined Purisima Formation is southward, toward and beneath Monterey Bay.
Recharge Areas
Recharge is from deep percolation of rainfall, especially near the upper watersheds of Soquel, Branciforte, and Arana-Rodeo Creeks. Recharge also occurs along the streambeds of Soquel and Aptos Creeks, and other minor creeks.
Groundwater Level Trends
Purisima Formation Coastal water levels have declined in the central portion of the Soquel Creek Water District between about New Brighton Beach and Aptos Creek, notably in the Purisima A subunit where water levels have been near historic low and continuously below sea level during the drought periods of the late 1980s and early 1990s. Groundwater levels have since partially recovered such that they fluctuate seasonally above and below sea level (SCWD 2003).
Aromas Red Sands Groundwater levels throughout SCWD’s Aromas well field area remain above sea level. At one monitoring location at the southern end, coastal water levels were essentially at sea level until recently; presently, levels are about five feet above sea level (SCWD 2003).
Groundwater Storage
Groundwater Storage Capacity. The total storage capacity of the basin has not been determined.
California’s Groundwater Bulletin 118
Central Coast Hydrologic Region Soquel Valley Groundwater Basin
Groundwater Budget (Type C)
There are not enough data to estimate a budget for this basin. Within the Soquel-Aptos area, pumpage in the Pursima Formation was estimated by the Santa Cruz County Environmental Health Department in October 1999 to be about 6,890 acre-feet, including 2,200 acre-feet for private pumping, about 910 acre-feet for the Central Water District and the City of Santa Cruz, and 3,780 acre-feet for the Soquel Creek Water District (SCWD 2001a). Pumpage from the Aromas Red Sands was estimated by SCWD in December 1998 to be about 6,240 acre-feet, including 3,650 acre-feet for private pumping, 490 acre-feet by Central Water District, and 2,100 acre-feet by SCWD (SCWD 2003).
Groundwater Quality
Characterization. Groundwater in the Purisima formation can generally be classified into two water quality types. In the Purisima A subunit, groundwater is a calcium-bicarbonate water; in the upper Purisima subunits, groundwater is generally a calcium-magnesium bicarbonate water (LSCE 1996). Based on data for the SCWD water supply wells, TDS values in the Purisima formation range from 310 to 850 mg/L, with an average value of 492 mg/L (based on 11 wells; SCWD 2001b). EC values range from 440 to 1,000 μmhos/cm, with an average value of 721 (SCWD 2001b). TDS values in the Aromas Red Sands Formation range from 160 to 290 mg/L, with an average value of 237 mg/L (based on 6 wells; (SCWD 2001b). EC values range from 240 to 425 μmhos/cm, with an average value of 348 μmhos/cm (SCWD 2001b).
Impairments. Declining coastal groundwater levels in the area between New Brighton Beach and Aptos Creek are of concern. The Purisima Formation aquifer produces water with elevated levels of iron and manganese. Most municipal wells are treated for manganese and iron at the wellhead (SCWD 1999a and 2000b).
Water Quality in Public Supply Wells
California’s Groundwater Bulletin 118
Constituent Group1
Inorganics – Primary Radiological
VOCs and SVOCs Inorganics – Secondary
Number of wells sampled2 14
10 10 8 8 14
Number of wells with a concentration above an MCL3 0
0 0 0 0 8
1 A description of each member in the constituent groups and a generalized discussion of the relevance of these groups are included in California’s Groundwater – Bulletin 118 by DWR (2003).
2 Represents distinct number of wells sampled as required under DHS Title 22 program from 1994 through 2000.
3 Each well reported with a concentration above an MCL was confirmed with a second detection above an MCL. This information is intended as an indicator of the types of activities that cause contamination in a given basin. It represents the water quality at the sample location. It does not indicate the water quality delivered to the
Central Coast Hydrologic Region Soquel Valley Groundwater Basin
consumer. More detailed drinking water quality information can be obtained from the local water purveyor and its annual Consumer Confidence Report.
California’s Groundwater Bulletin 118
Well Characteristics
Well yields (gal/min)
Total depths (ft) Domestic Municipal/Irrigation
Range: 276 – 1,373
Range: 316 – 930
Active Monitoring Data
Average: 662
(16 SCWD wells)
Average: 607
( 16 SCWD wells)
Number of wells /measurement frequency
10 Monthly
34 Varies
10 Annually 34 Varies
16 Varies
Department of Health Services and cooperators
Parameter Groundwater levels
Mineral, nutrient, & minor element.
Title 22 water quality
Basin Management
Groundwater management: Water agencies
Public Private
References Cited
SCWD Adopted AB 3030 Plan, April 1996
SCWD and Central Water District None
California Department of Health Services (DHS), 2000. California Water Quality Monitoring Database; Division of Drinking Water and Environmental Management, Sacramento [on CD-ROM].
California Department of Water Resources, San Joaquin District. Well completion report files.
Green, Gary H. 1977. Geology of the Monterey Bay Region. USGS Open File Report 77-718.
Luhdorff and Scalmanini, Consulting Engineers. 1981. Review and Analysis of Reports Relating to Ground-Water Resources in the Soquel-Aptos Area, Santa Cruz County, California. Soquel Creek Water District.
________ .1984. Groundwater Resources and Management Report, 1983, Soquel Creek Water District.
________. 1985. Groundwater Resources and Management Report, 1984, Soquel Creek Water District.
________. 1996. Soquel Creek Water District and Central Water District, AB3030 Ground- Water Management Plan Soquel-Aptos Area.
Muir, K.S., 1980. Seawater Intrusion and Potential Yield of Aquifers in the Soquel-Aptos Area, Santa Cruz County, California; U.S.G.S. Water-Resources Investigation 80-84, 29 p.
Central Coast Hydrologic Region Soquel Valley Groundwater Basin
Rains, Melton, Carella (RMC). 2001. Pajaro Valley water Management Agency-Revised Basin Management Plan (Draft).
Soquel Creek Water District (SCWD), 1999a. SCWD February 16, 1999 news release.
________. 1999b. SCWD September 2, 1999 news release.
________. 2000a. 1999 Water Quality Report [prepared in compliance of annual public notification requirements].
________. 2000b. Unpublished data provided by District engineers.
Thorup, R.R., 1981. Groundwater Review of the Soquel-Aptos Area, Santa Cruz County,
California; consultant report prepared for the Santa Cruz Builders Exchange, 125p.
________. 2001a. Urban Water Management Plan Update 2000
________. 2001b. Title 22 Water Quality Data.
________. 2003. Comments and Corrections to B-118, Soquel Valley Groundwater Basin write-up.
Additional References
Akers, J.P. and Hickey, J.J. 1966. Geohydrologic Reconnaissance of the Soquel-Aptos area, Santa Cruz County, California: U.S. Geological Survey open-file report, 58 p.
Bader, J.S. 1969. Groundwater Data as of 1967, Central Coastal Subregion, California. USGS Open file report. 16 p.
Bloyd, R.M. 1981. Approximate ground-Water-Level Contours, April 1991, for the Soquel- Aptos Area, Santa Cruz County, California; U.S.G.S. 81-680.
California Department of Water Resources (DWR). 1975. Bulletin No. 63-5. Sea-Water Intrusion in California, Inventory of Coastal Groundwater Basins. 394 p.
California State Water Resources Board (SWRCB). 1953. Bulletin No. 5, Santa Cruz- Monterey Counties Investigation, 230 p.
Hickey, J.J. 1968. Hydrogeologic Study of the Soquel-Aptos area, Santa Cruz County, California; U.S. Geological Survey open file report , 48 p.
Jennings, C.W. and Strand, R.G. (compilers). 1958. Santa Cruz Sheet of Geologic Map of California. California Division of Mines and Geology (CDMG). Scale 1:250,000.
Luhdorff and Scalmanini, Consulting Engineers. 1987. Groundwater Monitoring and Management, Aromas Red Sands, 1987. Soquel Creek Water District.
________. 1990. Groundwater Monitoring and Management 1990 Update, Aromas Red Sands. Soquel Creek Water District.
Muir, K.S. and Johnson, J.J., 1979. Classification of Ground-Water Recharge Potential in Three Parts of Santa Cruz County, California; U.S.G.S. Water-Resources Investigation Open file report 79-1065
Thorup, R.R., 1987. Groundwater Review of the Soquel-Aptos Area, Santa Cruz County, California; consultant report for the Santa Cruz Builders Exchange, 125 p.
Changes made to the basin description will be noted here.
California’s Groundwater Bulletin 118

Today we chatted again with Carolyn Remick, who directs the Berkeley Water Center, a consortium of UC Berkeley researchers who study water. She knows a lot about the many facets of water data in California.

We told her about how we are now doing this "Summer of Groundwater," and focusing on getting something concrete done, which might help facilitate broader dialogues about groundwater in California. We had learned from Carolyn a few months back about the need for work on groundwater, and that was what inspired us to jump in and do something helpful.

Apparently, we have good timing, because there is a lot of new legislation in California that is coming up that will effect groundwater. We will find out more about what this legislation is and what it means for California.

We also asked her the same questions we asked David Zetland about groundwater:

Groundwater has many facets such as aquifer location, aquifer type, land subsidence, water levels, water quality, sensor location, sensor distribution, drinking quality standards. What is the clearest and most useful narrative tell the general public.

What do we need to know first that will be the most impactful?

Is there water in the aquifers?

Both Carolyn and David suggested that we look into the issue of water quantity in the aquifers. Water quality, if it was drinkable or not, is also important, but you need to know where the water is first, and what it is useful for!

After our call, we broke down the basic questions about groundwater into this 'tree.' We are trying to eliminate complexity so that we can make sure to release something that is useable by the end of the summer. If we do a good job with our first groundwater visualization we, or anyone, can add to it.

Essential Questions about Groundwater

Laci has been researching groundwater & groundwater data for the last few weeks, and blogging about where he found it, so we now have a good idea of where information is.

What is Groundwater?

Groundwater is water that exists in the ground in aquifers. In California this is often a gravelly area in the Earth, that sort of acts as a sponge to hold water. This water can be pumped out, or pumped into, to act as water storage. Since we are in a drought, the surface water is scarce in places, and so farmers have to "turn their pumps on," and pump water from the ground to water the food we eat (40% of which, sidenote, we wind up throwing away, which includes food from restaurants, convention centers, expired food etc that we wind up throwing away for legal reasons.)

What is an aquifer?

An aquifer is the container, a geologic structure, in the ground that has the capacity to hold water. Not all aquifers have water in them. If an aquifer goes dry, it's not always possible to fill it back up again. When an aquifer empties, it can collapse. Such an effect produces large regions that sink or "subside" and thus become newly created flood plains. Aquifers that compact can forever be broken, and therefore never bear water in their newly consolidated state.

Do we have data for where the aquifers are?
Yes. We have data for aquifers. The data we are working with lives on Github, and will be improved throughout the summer.

Community Feedback/User Research opportunity

We can interview people who don't know about groundwater to learn what they want to know, and get these answers to be well written.

Proposed logic map for groundwater interactive

Community Feedback/User Research opportunity

We have this basic outline of questions based on research and interviewing researchers. We can build a paper prototype of this, and put it in front of a few people to see what kinds of questions come up. This should help with framing the map to be more understandable for the average person as well as the average researcher.

1. Where are aquifers?

We can map the aquifers. Here is a a still image of where they are. The point of what we are doing this summer to to make it easier for everyone to map the aquifers, via tutorials in Tilemill, etc.

2. Is there water in the aquifer?

Short answer: Sometimes. This changes. Not all water is drinkable.

  • Yes. If YES:
    • How much water is there? (...and this is the level)
    • Is this level a steady level? (usgs has historic levels) - what is the level?
    • Was it always this way? (time series data)
    • Is this ground water depleting? and if so how fast?
    • Is this ground water being recharged? and if so how?
    • Is this groundwater being recharged in a sustainable / healthy way?
    • If yes - how?
    • How certain are we? (Grades: DWR's Bulletin 118, BUDGET_TYP, uses withdrawal vs. deposit model)
    • A - Groundwater budget understood
    • B - Estimated
    • C - Little known about groundwater budget
    • For later: If yes, Is this water OK? Yes / No / I don’t know / It’s complicated
      We are not going to talk about the water quality yet. That will be added in after we answer basic questions about where the groundwater is.
    • What is the level over time?
  • Kind of: On a Gradient in between YES / NO
    • Sometimes, borderline, Yellow, something’s going wrong here, threatened aquifer
    • Yes but the level wavers. (& Why?)
    • Threatened and almost extinct - can it be saved?
    • This is going extinct and that was always the plan.
    • Are you serious, really? (Yes... link to historical Alaska plans)
    • Does it have to be this way?
    • How could we fix this? - suggestion, share information, help us
  • No. If NO:
    • How? How to fix it?
    • If data & no water (DRY)
    • What is the likelihood of land subsidence?
    • Can be recharged?
    • Already a subsided?
    • How could we fix this? - suggestion, share information, help us
  • We don’t know.
    • Why?
    • No data, no local regulations, no state regulation.
    • Start open data collection to fill in uncertain information
    • How could we fix this? - suggestion, share information, help us

More general questions

  • Why does this matter?
  • Why do we need this information?
  • How do we depend on the groundwater, and how much?
  • Who pumps water out, and why?
  • people that need well water if not connected to municipal supply
  • Where is groundwater running out?
  • Is the groundwater part of a sustainability program?
  • Will groundwater running out effect the price of water?
  • How do changes in groundwater relate to drought?
  • How does groundwater extraction effect surface water?
  • Where is the land going to cave in? (subsidence/sink holes)
  • Is it economical to pump a given aquifer? Paying for pumping vs. value of the water itself. For example, for an agricultural operation with surface rights & access to groundwater basin, there is a threshold to start using their water right again, it might be more economical to use surface water. Some farmers sell water rights and pumping aquifers with no regulations. The economics of this work in their benefit. Sort of a “peak water” situation.
  • Where are aquifers being recharged? For example, injection wells. Paying money to push water back into aquifers, injecting surface water into groundwater basins to store it in a "water in/water out" model. Natural vs. artificial recharge.
  • How fast is the groundwater being depleted?
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